benzofurans and dibenzo(1-4)dioxin

The Yusho incident is an unprecedented mass food poisoning that occurred in Japan in 1968. It was caused by the ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The victims of Yusho have suffered from characteristic skin manifestations associated with systemic, ophthalmological, and mucosal symptoms for a long period of time. The Study Group of Yusho (the Yusho Group) has been conducting annual medical check-ups on Yusho victims for more than 45years. Since 2002, when concentrations of dioxins in the blood of Yusho patients started to be measured, the pharmacokinetics of dioxins, relationship between blood levels of dioxins and symptoms/signs in patients directly exposed to dioxins, and the adverse effects on the next generation have become dramatically clear. Herein we review recent findings of studies conducted by the Yusho Group to evaluate chronic dioxin-induced toxicity to the next generation as well as Yusho patients in comparison with a similar food mass poisoning, the Yucheng incident. Additionally, we summarized basic studies carried out by the Yusho Group to re-evaluate the mechanisms of dioxin toxicities in experimental models and various functions of the aryl hydrocarbon receptor (AhR), known as the dioxin receptor, pathway.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Foodborne Diseases; Humans; Japan; Male; Middle Aged; Plant Oils; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Receptors, Aryl Hydrocarbon; Rice Bran Oil

The Yangtze River has been a source of life and prosperity for the Chinese people for centuries and is a habitat for a remarkable variety of aquatic species. But the river suffers from huge amounts of urban sewage, agricultural effluents, and industrial wastewater as well as ship navigation wastes along its course. With respect to the vast amounts of water and sediments discharged by the Yangtze River, it is reasonable to ask whether the pollution problem may be solved by simple dilution. This article reviews the past two decades of published research on organic pollutants in the Yangtze River and several adjacent water bodies connected to the main stream, according to a holistic approach. Organic pollutant levels and potential effects of water and sediments on wildlife and humans, measured in vitro, in vivo, and in situ, were critically reviewed. The contamination with organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), and others, of water and sediment along the river was described. Especially Wuhan section and the Yangtze Estuary exhibited stronger pollution than other sections. Bioassays, displaying predominantly the endpoints mutagenicity and endocrine disruption, applied at sediments, drinking water, and surface water indicated a potential health risk in several areas. Aquatic organisms exhibited detectable concentrations of toxic compounds like PCBs, OCPs, PBDEs, and PFCs. Genotoxic effects could also be assessed in situ in fish. To summarize, it can be stated that dilution reduces the ecotoxicological risk in the Yangtze River, but does not eliminate it. Keeping in mind an approximately 14 times greater water discharge compared to the major European river Rhine, the absolute pollution mass transfer of the Yangtze River is of severe concern for the environmental quality of its estuary and the East China Sea. Based on the review, further research needs have been identified.

Topics: Animals; Benzofurans; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Halogenated Diphenyl Ethers; Humans; Hydrocarbons, Chlorinated; Pesticides; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Rivers; Wastewater; Water Pollutants, Chemical; Water Pollution, Chemical

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Humans; Occupational Exposure

Thyroid hormones play a critical role in the proper development of brain function and cell growth. Several epidemiological studies have been conducted to assess potential associations between pre- and post-natal exposure to dioxins or dioxin-like compounds (DLCs) and the levels of circulating thyroid hormones during early development. Dioxins and DLCs include chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and mono- and non-ortho polychlorinated biphenyls (PCBs). We identified a total of 23 relevant epidemiological studies (21 cohort studies and 1 case-control study) that measured exposures to various types of dioxins and DLCs as well as markers of thyroid function, such as thyroid stimulating hormone (TSH), total thyroxine (T4), free T4, total triiodothyroxine (T3), free T3, and thyroid-binding globulin concentrations in cord blood or circulation. While some of the studies reported associations between concentrations of dioxins and/or DLCs and some biomarkers of thyroid function, the majority of the observed associations were not statistically significant. Moreover, there were no clear and consistent effects across studies for any of the hormone levels examined, and while a number of studies showed a statistically significant association with exposure for a given marker of thyroid function, other studies showed either no change or changes in the opposite direction for the same thyroid function marker. Similarly, when the results were analyzed considering developmental stage, there generally were no clear and consistent effects at any age from birth through 12 years of age. The absence of a clear correlation between background exposures to dioxins and DLCs and thyroid function biomarkers during development is not consistent with the hypothesis that background exposures to these chemicals cause effects on thyroid function during development.

Topics: Benzofurans; Biomarkers; Dioxins; Environmental Exposure; Humans; Infant, Newborn; Polychlorinated Biphenyls; Thyroid Gland; Thyroid Hormones; Thyrotropin

Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were introduced into the biosphere on a large scale as by-products from the manufacture of chlorinated phenols and the incineration of wastes. Due to their high toxicity they have been the subject of great public and scientific scrutiny. The evidence in the literature suggests that PCDD/F compounds are subject to biodegradation in the environment as part of the natural chlorine cycle. Lower chlorinated dioxins can be degraded by aerobic bacteria from the genera of Sphingomonas, Pseudomonas and Burkholderia. Most studies have evaluated the cometabolism of monochlorinated dioxins with unsubstituted dioxin as the primary substrate. The degradation is usually initiated by unique angular dioxygenases that attack the ring adjacent to the ether oxygen. Chlorinated dioxins can also be attacked cometabolically under aerobic conditions by white-rot fungi that utilize extracellular lignin degrading peroxidases. Recently, bacteria that can grow on monochlorinated dibenzo-p-dioxins as a sole source of carbon and energy have also been characterized (Pseudomonas veronii). Higher chlorinated dioxins are known to be reductively dechlorinated in anaerobic sediments. Similar to PCB and chlorinated benzenes, halorespiring bacteria from the genus Dehalococcoides are implicated in the dechlorination reactions. Anaerobic sediments have been shown to convert tetrachloro- to octachlorodibenzo-p-dioxins to lower chlorinated dioxins including monochlorinated congeners. Taken as a whole, these findings indicate that biodegradation is likely to contribute to the natural attenuation processes affecting PCDD/F compounds.

Topics: Aerobiosis; Bacteria; Benzofurans; Biodegradation, Environmental; Dibenzofurans, Polychlorinated; Dioxins; Molecular Structure; Polychlorinated Dibenzodioxins

Analytical techniques for the determination of polychorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and dioxin-like PCBs (DLPCB) are reviewed. The focus of the review is on recent advances in methodology and analytical procedures. The paper also reviews toxicology, the development of toxic equivalent factors (TEF) and the determination of toxic equivalent quantity (TEQ) values. Sources, occurrence and temporal trends of PCDD/PCDF are summarized to provide examples of levels and concentration ranges for the methods and techniques reviewed.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollutants; Humans; Polychlorinated Biphenyls

This article reviews the state of the science regarding the health effects of polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs). While thousands of articles have been published on the health effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs), little is know about the brominated and mixed chloro/bromo homologs. Available literature suggests that brominated compounds have similar toxicity profiles to their chlorinated homologs. However, further research investigating health effects will only be useful if exposure scenarios truly exist. Current exposure data is extremely limited, posing a major data gap in assessing potential risk of these chemicals. The rapid increase in the use of brominated flame retardants has raised the level of environmental concern regarding PBDDs/PBDFs as it is likely that human, as well as wildlife, exposure to brominated dioxins and furans will increase with their use.

Topics: Benzofurans; Dioxins; Environmental Exposure; Hydrocarbons, Brominated; Public Health

Polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs) occur as trace (ppb) contaminants in brominated flame retardants and are produced during combustion of these chemicals. They are also formed when organics are incinerated in the presence of bromine, e.g., in municipal and industrial incinerators and in internal-combustion engines. Combustion of organics in the presence of both bromine and chlorine results in the formation of mixed (i.e., bromo, bromo/chloro and chloro) halogenated dibenzo-p-dioxins and dibenzofurans (HDDs and HDFs). There are 4600 potential mixed congeners. The biological effects of PBDDs and PBDFs are similar, if not identical, to those of PCDDs and PCDFs. Both groups of compounds induce hepatic aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-o-deethylase (EROD) in rats and cause wasting and thymic atrophy in rats and guinea pigs. Tetrabrominated dinenzo-p-dioxin (TBDD) and dibenzofuran (TBDF) are reproductive toxins in mice and produce skin lesions in the rabbit-ear acnegenic test. The brominated compounds appear to bind to the same cytosolic receptors believed to mediate the toxicities of the chlorinated analogs. When compared on a molar-concentration basis, the brominated compounds are equipotent to the chlorinated analogs. TBDD is absorbed after oral, dermal, or intratracheal administration in rats, stored in the liver and adipose tissue, and eliminated in the feces through biliary excretion. The biological half-lives of the brominated compounds appear to be somewhat shorter than those of the corresponding chlorinated species. The brominated compounds, like their chlorinated congeners, have the potential to cause dermal, hepatic, and gastrointestinal toxicities in humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Benzofurans; Dioxins; Female; Humans; Male; Tissue Distribution

The experimental and theoretical data available concerning the gas- and particle-phase reactions of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) are discussed. These data lead to the expectation that the dominant tropospheric loss processes of gas-phase PCDDs and PCDFs will be photolysis and reaction with the OH radical, with the OH radical reaction being the most important for the less chlorinated species. The estimated tropospheric lifetimes of gas-phase PCDFs increase significantly more rapidly with the degree of chlorination than is the case for PCDDs. For particle-associated PCDDs and PCDFs, the dominant tropospheric removal processes are expected to be photolysis and wet and dry deposition, with wet and dry deposition of the host particles being the most important. The estimated lifetimes in the lower troposphere range from less than 1 day for dibenzo-p-dioxin, the mono-, di- and trichlorodibenzo-p-dioxins, dibenzofuran and the monochlorodibenzofurans present in the gas phase, to greater than or equal to 10 days for particle-associated PCDDs and PCDFs, with a general increase in the tropospheric lifetime with the degree of chlorination. While long-range transport of PCDDs is expected to occur for those PCDDs which are totally or mainly particle associated, gas- and particle-phase PCDFs containing four or more chlorine atoms are also expected to have sufficiently long tropospheric lifetimes to undergo long-range transport.

Topics: Air Pollutants; Atmosphere; Benzofurans; Dioxins; Drug Stability; Molecular Structure; Photolysis; Polychlorinated Dibenzodioxins; Polymers

Topics: Animals; Benzofurans; Dioxins; Humans; Risk Factors; Soil Pollutants; Water Pollutants, Chemical

Blubber from Faroese pilot whales (Globicephala melas) was analysed for brominated dioxins PBDD/Fs, with a subset also analysed for chlorinated dioxins, PCDD/Fs. The studied individuals were restricted to juvenile male whales sampled in the Faroe Islands during the period 1997-2013. Among the PBDD/Fs, the furans were predominant, although the relative abundance of various congeners differed between samples. Furans accounted for, on average, 79% of the ∑PBDD/Fs in the samples, with 1,2,3,4,6,7,8-HpBDF the most abundant congener, found in half of the analysed pilot whales. The concentration range for ∑PBDD/Fs among the samples was 0.080-71 pg/g l.w. (lipid weight), and the sum of toxic equivalents ranged from 0.0039 to 4.7 pg TEQ/g l.w. No relationship was found between PBDD/Fs and PCDD/Fs. In addition, 20 pilot whale samples from the period 2010-2013 were analysed for PBDEs. Several PBDE congeners were found in all of the sampled pilot whales, and at noticeably higher levels than PBDD/Fs and PCDD/Fs. The ∑PBDEs ranged from 140 to 1900 ng/g l.w., with BDE #47 the most abundant congener detected in the samples. Results from the present study were then compared with data from previous studies on pilot wales to investigate temporal trends between 1986 and 2013. The comparison indicated that PBDE concentrations in juvenile males have decreased from 1996 to the latest observations in 2013. No relationship between the concentration levels of PBDD/Fs and PBDEs in the sampled pilot whales could be identified, which indicates possible differences in the metabolism of, or exposure to, PBDEs and PBDD/Fs.

Topics: Animals; Benzofurans; Denmark; Dibenzofurans; Dioxins; Environmental Monitoring; Furans; Halogenated Diphenyl Ethers; Male; Wales; Whales, Pilot

Polychlorinated naphthalenes (PCNs) have been found widely in the aquatic environment and can be transferred through food chains, which can magnify or dilute their toxic effects on humans. In this study, PCNs were analyzed in samples of 17 species of fish with different dietary habits collected in the Bohai coastal area in China. Dichloronaphthalenes, which have rarely been quantified in previous studies, were determined. The total PCN concentrations were from 7.3 to 214 pg/g wet weight, and the highest concentration was found in ditrema. The trichloronaphthalenes were the most abundant PCNs, followed by the dichloronaphthalenes and pentachloronaphthalenes. The relatively high contributions of the less-chlorinated homologs to the total PCN concentrations indicated that the main PCN sources around the Bohai were industrial thermal process emissions rather than technical PCN formulations. The trophic magnification factors of the PCN homologs were from 3.1 to 9.9, indicating that PCNs were biomagnified by fish. The trophic magnification factor of dichloronaphthalene and trichloronaphthalenes was 5.8 and 6.4, respectively, indicating for the first time that dichloronaphthalene and trichloronaphthalenes can undergo trophic magnification by fish. The two highest trophic magnification factors were for the pentachloronaphthalenes and hexachloronaphthalenes, probably because these PCNs having fewer vicinal carbon atoms without chlorine atoms attached are less easily biotransformed than the other homologs. The dioxin-like toxicities of the PCNs in the samples, expressed as potential toxic equivalences (TEQs), were assessed. The highest total TEQ was 0.0090 pg/g ww, in Pacific herring, and the hexachloronaphthalenes were the dominant contributors to the total TEQs in the fish samples. The PCN TEQs were much lower than the polychlorinated dibenzo-p-dioxin and dibenzofuran and dioxin-like polychlorinated biphenyl TEQs found in fish from the Bohai in previous studies, and made marginal contributions to overall human exposure to dioxin-like TEQs, suggesting that PCNs pose no toxicological concerns.

Topics: Animals; Benzofurans; China; Dioxins; Fishes; Naphthalenes; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Seafood; Water Pollutants, Chemical

Accidental fires and open combustion are regarded as major potential contributors to the environmental release of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs). The characterization of PBDD/Fs emitted from thermal treatment of simulated polystyrene (PS) foam is reported in this study. PS, hexabromocyclododecane (HBCDD) and metals (or metallic compounds) composed the test samples, which imitated real extruded (XPS) and expanded (EPS) polystyrene thermal insulation foams. Test samples were subjected to thermal treatments under different experimental conditions. This study shows that the temperature, metal (metallic compound) content, and type of atmosphere are the key factors in the formation of congeners and PBDD/Fs during thermal processes. The total yield of polybrominated dibenzofurans (PBDFs) was greater than that of the polybrominated dibenzo-p-dioxins (PBDDs) during the test, and 1,2,3,7,8-PeBDF and 2,3,7,8-TBDF were the predominant congeners emitted during the thermal treatment experiments.

Topics: Benzofurans; Dioxins; Metals; Polystyrenes

In addition to unintentional formation of polychlorinated (PCDD/Fs), polybrominated (PBDD/Fs), and mixed halogenated (PXDD/Fs) dibenzo-p-dioxins/dibenzofurans during industrial activities, recent studies have shown that several PBDD and PXDD congeners can be produced by marine algal species from the coastal environment. However, multiple exposure status of anthropogenic and naturally derived dioxins in marine organisms remains unclear. The present study examined the occurrence, geographical distribution, and potential sources of PCDD/Fs, PBDD/Fs, and PXDD/Fs using mussels and brown algae collected in 2012 from Seto Inland Sea, Japan. The results showed the widespread occurrence of not only PCDD/Fs but also PBDDs and PXDDs in Seto Inland Sea. The geographical distribution pattern of PBDDs was similar to that of PXDDs, which were obviously different from that of PCDDs and PCDFs, and a significant positive correlation was observed between the levels of their predominant congeners, i.e., 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs. Interestingly, potential precursors of 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs, hydroxylated tetrabrominated diphenyl ethers (6-HO-BDE-47 and 2'-HO-BDE-68) and their mixed halogenated analogue (HO-TrBMoCDE), were also identified in the mussel and brown alga samples collected at the same site, by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-ToFMS) analyses. It is noteworthy that residue levels of 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs in the mussel were 30 times higher than those in the brown alga, suggesting the bioaccumulation of these natural dioxins.

Topics: Animals; Benzofurans; Bivalvia; Dioxins; Environmental Monitoring; Japan

The thermal treatment of waste electrical and electronic equipment (WEEE) is regarded as the largest potential contributor to the environmental release of polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs). Herein, the pyrolysis of decabromodiphenyl ether (deca-BDE), polyethylene (PE) and metal blends was conducted to investigate the emission characteristics of PBDD/Fs at different thermal treatment conditions. The total yield of polybrominated dibenzo-p-dioxins (PBDDs) was less than that of polybrominated dibenzofurans (PBDFs) during the pyrolysis of the PE matrix and metal blends. 2,3,7,8-TBDF and 1,2,3,7,8-PBDF were the dominant congeners emitted from the pyrolysis. Temperature, presence of oxygen and type of added metal were the critical influencing factors for the PBDD/F formation rates and speciation in the pyrolysis process.

Topics: Air Pollutants; Benzofurans; Dioxins; Electronic Waste; Halogenated Diphenyl Ethers; Incineration; Metals; Polyethylene

Pine needles have been used for many decades as a cheap and convenient biosampler to monitor atmospheric levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), collectively known as PCDD/Fs. However, it is unknown whether accumulation of PCDD/Fs varies according to pine tree species or pine needle age, which hampers the precise application of this biosampler. We collected 0.3-2.3-year-old pine needles from four different species of pine at three sites in Hangzhou City, Zhejiang Province, China. The PCDD/Fs were quantitatively analyzed by gas chromatography high-resolution mass spectrometry. The results show that Pinus massoniana and Cedrus deodara absorbed more PCDD/Fs than Pinus thunbergii and Pinus parviflora at the same site. More cuticular wax and cuticular cell secretions in the pine needles from P. massoniana and C. deodara, as observed by scanning electron microscopy (SEM), might explain this discrepancy. The PCDD/Fs concentrations in 0.3-, 1.3-, and 2.3-year-old pine needles, indicated that concentrations increase with ascending age. This may be ascribed to the enhancement of lipids and cuticular waxes with age in pine needles as indicated by the lipid contents and morphologies observed by SEM. Our results may be useful for selecting the species and age of pine needles used for biosampling, especially for monitoring PCDD/Fs in large areas where the pine species growing in one place may differ from those in another place.

Topics: Benzofurans; China; Cities; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Pinus; Plant Leaves; Polychlorinated Dibenzodioxins

There is significant concern regarding the contamination of riverine sediments with dioxins and dioxin-like compounds (DLCs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and some polycyclic aromatic hydrocarbons (PAHs). The majority of studies investigating the ecotoxicology of DLCs in fish have focused on a few standard model species. However, there is significant uncertainty as to whether these model species are representative of native river fish, particularly in Europe. In this study, the transcriptional responses following exposure to equipotent concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), PCB 156 or the dioxin-like PAH, benzo[k]fluoranthene (BkF), were investigated in juvenile roach (Rutilus rutilus), a fish species that constitutes a large proportion of the fish biomass in freshwater bodies throughout Europe. To this end, RNA sequencing analysis was used to comprehensively characterise the molecular mechanisms and pathways of toxicity of these DLCs. Whole transcriptome analyses using ClueGO software revealed that DLCs have the potential to disrupt a number of important processes, including energy metabolism, oogenesis, the immune system, apoptosis and the response to oxidative stress. However, despite using equipotent concentrations, there was very little conservation of the transcriptional responses observed in fish exposed to different DLCs. TCDD provoked significant specific changes in the levels of transcripts related to immunotoxicity and carbohydrate metabolism, while PCB 156 caused virtually no specific effects. Exposure to BkF affected the most diverse suite of molecular functions and biological processes, including blood coagulation, oxidative stress responses, unspecific responses to organic or inorganic substances/stimuli, cellular redox homeostasis and specific receptor pathways. To our knowledge, this is the first study of the transcriptome-wide effects of different classes of DLCs in fish. These findings represent an important step towards describing complete toxicity pathways of DLCs, which will be important in the context of informing risk assessments of DLC toxicity in native fish species.

Topics: Animals; Benzofurans; Cyprinidae; Dibenzofurans, Polychlorinated; Dioxins; Environmental Pollutants; Europe; Gene Expression; Gene Expression Profiling

The formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) was explored during de novo tests designed to compare the catalytic activity of copper (II) chloride (CuCl2) with that of iron (III) oxide (Fe2O3) and to test some synergistic effect between these two catalytic compounds. Both copper chloride (CuCl2) and iron oxide (Fe2O3) were earlier proposed as catalysts to explain the PCDD/F emissions from, e.g. municipal solid waste incineration (MSWI). In addition, haematite (Fe2O3) is the main iron ore and could be responsible for the typical iron ore sintering plant fingerprint. A total of nine model fly ash (MFA) samples were prepared by mixing and grinding of sodium chloride (NaCl), activated carbon and a powder matrix of silica (SiO2) with the selected metal compound(s). The conditions of these de novo tests were 1 h in duration, 350 °C in a flow of synthetic combustion gas (10 vol.% oxygen in nitrogen). The effect of Fe-Cu catalyst concentration on yield and distribution pattern of PCDD/F was systematically explored; three strongly differing ratios of [Fe]:[Cu] were considered (1:1, 10:1 and 100:1) to study the potential interactions of Fe2O3 and CuCl2 suggested earlier. The results show some slight rise of PCDD/F formed with raising iron concentration from 0 to 10.1 wt% (no Cu added; 0.1 wt% Cu), as well as strong surging of both amount and average chlorination level of PCDD/F when rising amounts of copper (0 to 1.1 wt%) are introduced. The resulting fingerprints are compared with those from sintering and from MSWI.

Topics: Benzofurans; Catalysis; Coal Ash; Copper; Dioxins; Ferric Compounds; Incineration; Polychlorinated Dibenzodioxins

Dioxins and dioxin-like compounds (DLCs) are potent toxicants to most vertebrates. Sensitivities to DLCs vary among species. In the present study, the sensitivities of avian species (chicken [Gallus gallus], ring-necked pheasant [Phasianus colchicus], and Japanese quail [Coturnix japonica]) to some polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were determined by using species-specific, in vitro, transactivation assays based on a luciferase reporter gene under control of species-specific aryl hydrocarbon receptors. In ring-necked pheasant and Japanese quail, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was not the most potent inducer of toxic effects. Especially for Japanese quail, the relative potency values of most of 9 PCDD/Fs tested were greater than for TCDD. The rank order of avian species sensitivities to DLCs was chicken > ring-necked pheasant > Japanese quail. Effects of binary mixtures of TCDD, 2,3,7,8-tetrachlorodibenzofuran, and 2,3,4,7,8-pentachlorodibenzofuran were strictly additive. Moreover, we also found that the primary DLCs that were responsible for most of the potency of the DLC mixtures can be deduced by using ordination in a multidimensional space defined by the avian species sensitivities. Overall, the relative potency and the species sensitivities of these chemicals could guide risk assessments to wild species when exposure to mixtures of DLCs in the environment.

Topics: Animals; Benzofurans; Chickens; Coturnix; Dioxins; Dioxins and Dioxin-like Compounds; Galliformes; Genes, Reporter; Luciferases; Polychlorinated Dibenzodioxins; Receptors, Aryl Hydrocarbon; Species Specificity; Transcriptional Activation

The relationship of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in sediment, water, and fish was studied for 55 fish farms near a contaminated site in Tainan, Taiwan. Samples were collected from the farms and analyzed for seventeen 2,3,7,8-substituted PCDD/Fs congeners. High correlations were found between PCDD/Fs in water and sediment in regard to both concentration and toxicity (R(2) = 0.933 for concentration and R(2) = 0.832 for toxicity). The congener profiles of the 17 PCDD/Fs in water were similar to those in the sediment. However, the PCDD/Fs congener composition in the fish and fish belly samples were different from those in the sediment and water samples obtained from the same fish farm and were also different among the fish samples. It is thus suggested that the biotic PCDD/Fs distribution is more complex than the abiotic PCDD/Fs distribution. Among the seven factors analyzed, only the lipid percentage presented a relationship with the PCDD/Fs congener composition in the fish and fish bellies. A multiple linear regression of the concentration of each congener in the fish was conducted using the concentration of each congener in the site-matched sediment and the lipid content of the fish as independent variables. The results showed that only seven PCDD/Fs congeners with a lower degree of chlorination, which were 4-6 chlorine substitutes, in the fish presented a significant correlation with the lipid content in the fish and their concentration in sediment (r > 0.65, P < 0.005 for both independent variables). In addition, the octanol-water partition coefficients were not significantly related to this distribution behavior.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollution; Fishes; Geologic Sediments; Seafood; Soil Pollutants; Stereoisomerism; Taiwan; Water Pollutants, Chemical

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are toxic and persistent organic pollutants that are able to enter the food chain, accumulate in the fat tissues of animals, and consequently pose a serious risk for human health. Consolidated tools for exposure assessment have been implemented during the last decades and widely used, both in the environmental monitoring and in modeling activities. Although the emissive trend and the concentrations in the environment have gradually decreased during the last 20 years, some situations are still underrated and not adequately controlled by the environmental legislation. On the other hand, a complete monitoring of all the pathways of exposure to PCDD/Fs and PCBs is technically and economically unfeasible. Therefore, this paper aims at providing an overview of the traditional approaches used to assess the impacts of PCDD/Fs and PCBs and presenting the novelties introduced during the last years. After an initial characterization of their toxicity and their effects on health, this paper focuses on activities and situations that can result in critical releases of PCDD/Fs and PCBs into the atmosphere and that can represent a hidden threat for the population. In the final part, this study presents the current methodologies for exposure assessment, summarizes the food chain models in a unified way, and puts the light on new methods that can help environmental scientists, risk assessors, and decision makers to estimate the risk related to exposure to PCDD/Fs in different contexts.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollutants; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Risk Assessment

Levels and profiles of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) were analyzed for the first time in raw and treated water from five water treatment plants in Shenzhen, South China. The average PCDD/Fs concentrations were 32.93 pg/L (0.057 pg international toxic equivalent quantity (I-TEQ)/L) and 0.64 pg/L (0.021 pg I-TEQ/L) in raw and treated water, respectively. The removal rate of PCDD/Fs in terms of mass concentration varied from 93.4% to 98.8%, whereas a negative removal rate was observed in one plant in terms of TEQ concentration. The PCDD/Fs concentration in raw water was lower than most of the published data from other countries and regions, and the PCDD/Fs concentration in treated water was below the Maximum Contaminants Level (MCL) of 30 pg/L for dioxin in drinking water set by the US EPA. Historical pentachlorophenol usage, local waste incineration and industrial emissions, as well as surface runoff or even soil erosion, might be the main sources for PCDD/F pollution in water. The daily intake of PCDD/Fs for local residents from drinking water was estimated to be 0.69 fg I-TEQ/kg/day, which is negligible compared with that from food consumption (1.23 pg WHO-TEQ/kg/day) in the local area.

Topics: Benzofurans; China; Dibenzofurans, Polychlorinated; Dioxins; Drinking Water; Environmental Monitoring; Fresh Water; Polychlorinated Dibenzodioxins; Water Pollutants, Chemical; Water Purification

Information on environmental distribution and human exposures of polybrominated dibenzo-p-dioxins and dibenzo-furans (PBDDs/Fs) are little reported. In the present study, workshop dust, soil and sediment samples from Longtang and Shijiao, the intensive e-waste recycling sites within Qingyuan City, southern China, were collected and analyzed following the standard method. PBDD/F concentrations (sum of eight 2378-substituted PBDD/F congeners) in different environmental matrices were in the range of 122-4667 ng kg(-1) dry wt (dw) for workshop dust, 19.6-3793 ng kg(-1) dw for the top soils, and 527 ng kg(-1) dw for the surface sediment, which were substantially higher than those of reference sites. The long-distance transport of PBDDs/Fs also impacted the adjacent areas. Contribution of the most two toxic congeners (2,3,7,8-TBDD and 1,2,3,7,8-PeBDD) to the total toxic equivalent quantity (TEQ) increased significantly from "source" (dust) to "sink" (sediment). Dismantling and open burning were the two procedures contributing relatively higher level PBDDs/Fs to the atmosphere, while acid leaching would contaminate soils and waters directly. The estimated daily intakes of eight PBDD/F congeners via soil/dust ingestion and dermal absorption for local residents were higher than those contributed by seventeen PCDD/F congeners in the same set of samples. Children and e-waste processing workers were the most affected groups by the low-tech recycling activities there.

Topics: Benzofurans; China; Dioxins; Dust; Electronic Waste; Humans; Recycling; Soil

Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.

Topics: Benzofurans; Carbon; Coal Ash; Dioxins; Environmental Monitoring; Hazardous Substances; Incineration; Naphthalenes; Polychlorinated Dibenzodioxins; Solid Waste; Waste Products

Flocculants are widely used to improve the properties of sludge dewatering in industrial wastewater treatment. However, there have been no studies conducted on the influence of flocculants on the formation of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) during sewage sludge incineration. This paper selected three typical kinds of flocculants, including polyacrylamide (PAM), poly-ferric chloride (PFC), and polyaluminum chloride (PAC) flocculant, to study their influences on the formation of PCDD/Fs during sewage sludge incineration. The results indicated that PAM flocculant, which is an organic flocculant, inhibited the formation of PCDD/Fs in sewage sludge incineration, while inorganic flocculant, such as PFC and PAC flocculant, promoted the formation. The most probable explanation is that the amino content in the PAM flocculant acted as an inhibitor in the formation of PCDD/Fs, while the chlorine content, especially the metal catalyst in the PFC and PAC flocculants, increased the formation rate. The addition of flocculants nearly did not change the distribution of PCDD/F homologues. The PCDFs contributed the most toxic equivalent (TEQ) value, especially 2, 3, 4, 7, 8-PeCDF. Therefore, the use of inorganic flocculants in industrial wastewater treatment should be further assessed and possibly needs to be strictly regulated if the sludge is incinerated. From this aspect, a priority to the use of organic flocculants should be given.

Topics: Acrylic Resins; Aluminum Hydroxide; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Ferric Compounds; Flocculation; Incineration; Polychlorinated Dibenzodioxins; Sewage; Water Purification

This study was launched to establish comprehensive environmental monitoring on the levels and patterns of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polycyclic aromatic hydrocarbons (PAHs) both in soil and ambient air around a thermal desorption plant in China. All 209 congeners of PCBs, 136 congeners of PCDD/Fs (P = 4 to 8) and 16 EPA priority PAHs were analyzed. The concentration of PCBs ranged from 20.0 to 536 ng g(-1) (or 0.077-5.27 pg WHO-TEQ g(-1)) in soil and from 972 to 991 ng Nm(-3) (or 0.245-0.374 pg WHO-TEQ Nm(-3)) in air samples, much higher than the levels in cities. A single soil sampling point could have been affected by some transfer of PCBs from the untreated soil by the fingerprint characteristics and the statistical analysis. Establishing blank values prior to the start-up of new plant is a safe and sure method to establish subsequent impacts on the environment. During the treatment of hazardous waste, strict control of all waste materials and all emissions is required.

Topics: Air Pollutants; Benzofurans; China; Dioxins; Environmental Monitoring; Environmental Pollution; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Soil; Soil Pollutants

We present, in this study, mechanistic and kinetic accounts of the formation of dibenzofuran (DF), dibenzo-p-dioxin (DD) and their hydroxylated derivatives (OHs-DF/OHs-DD) from the catechol (CT) molecule, as a model compound for phenolic constituents in biomass. Self-condensation of two CT molecules produces predominantly a DD molecule via open- and closed-shell corridors. Coupling modes involving the o-semiquinone radical and the CT molecule (o-SQ/CT) generate two direct structural blocks for the formation of OHs-DF/OHs-DD structures, ether-type intermediates and di-keto moieties. The calculated reaction rate constants indicate that the fate of ether-type intermediates is to make hydroxylated diphenyl ethers rather than to undergo cyclisation reactions leading to the formation of preDF structures. Unimolecular loss of a H or OH moiety from a pivotal carbon in these hydroxylated diphenyl ethers then produces hydroxylated and non-hydroxylated DD molecules. Formation of OHs-DF initiated by o(C)-o(C) cross-linkages involving o-SQ/o-SQ and o-SQ/CT reactions incurs very similar reaction and activation enthalpies encountered in the formation of chlorinated DFs from chlorophenols.

Topics: Benzofurans; Catechols; Dioxins; Hydroxylation; Molecular Structure

A major part of sheep livers contains levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) above the former but to some extent also the new maximum levels (MLs) in the EU. In order to investigate the relationship between the intake of these contaminants and their accumulation in livers, kidney fat and meat, young blackhead sheep were fed with grass pellets containing PCDD/Fs at 2.5 times the maximum level. Levels of PCDD/Fs in livers were already quite high at the start of the exposure but increased 3-fold within 56d, exceeding the new product based MLs. Levels in meat and fat also increased but did not exceed the MLs. Although less elevated in the grass, both dl- and ndl-PCB levels also increased in liver and fat. Their kinetics in the tissues was less clear, potentially caused by increased levels in the straw given to the sheep during the whole experimental period. There was a clear difference in the behavior of the various congeners, the PCDFs and especially the higher chlorinated PCDFs and PCDDs showing a higher accumulation in the liver. In the case of the PCBs, this was particularly true for PCB 126. When switched to clean grass after 56d, the levels in livers and other tissues decreased to about the levels in the control sheep within 56d. This offers a potential solution for decreasing the intake of consumers.

Topics: Animal Feed; Animals; Benzofurans; Dioxins; Kidney; Liver; Muscle, Skeletal; Netherlands; Organ Size; Poaceae; Polychlorinated Biphenyls; Sheep; Tissue Distribution

In this study the occurrence of polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) in street dust samples was investigated using pressurized liquid extraction and gas chromatography coupled to mass spectrometry. Street dust samples were taken from rural, urban, industrial and industrially influenced urban areas. PCB6 concentrations ranged from 5090±2200 μg/kg (average±standard error of mean) in dusts from industrial premises to 29±8.7 μg/kg in rural areas. Concentration ranges were for dioxin-like PCB toxicity equivalents (dl-PCB TEQ) from 362±164 ng/kg (industrial premises) to 6.5±1.8 ng/kg (rural areas), and for PCDD/PCDF TEQ from 503±448 ng/kg to 2.4±0.13 ng/kg, respectively. Area concentrations of PCB6 (0.040 μg/m2-22 μg/m2), dl-PCB TEQ (0.0038 ng/m2-2.6 ng/m2) and PCDD/PCDF TEQs (14 pg/m2-1980 pg/m2) were estimated. Furthermore, particle size related concentrations of PCBs and PCDD/PCDFs in street dusts were analysed showing throughout almost all samples a distinctive trend of increasing concentrations with decreasing particle sizes. Characterization of homologue patterns of PCBs and PCDDs/PCDFs in street dusts was performed showing a dependence of homologue patterns on different area types, especially for PCBs. It could be demonstrated that the analysis of concentrations in combination with specific homologue patterns of PCBs and PCDDs/PCDFs in street dust samples enables allocation of potential emission sources.

Topics: Air Pollutants; Benzofurans; Dioxins; Dust; Environmental Monitoring; Germany; Polychlorinated Biphenyls

We compared polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations [expressed as toxic equivalent quantities (TEQs)] in agricultural soil samples from Chongming Island (Shanghai, China) determined using two analytical approaches, an enzyme-linked immunoassay (EIA) method and a high resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) method. The PCDD/F concentrations in all 31 soil samples were at background levels (7.30-16.7 pg EIA-TEQ/g from the EIA analysis and 0.526-1.99 pg WHO-TEQ/g from the HRGC/HRMS analysis). Although, the EIA method overestimated the PCDD/F concentrations compared with the concentrations determined using the HRGC/HRMS method. The absence of false-negatives showed by the EIA analysis verified that this method is useful for preliminary sample screening (prior to HRGC/HRMS analysis) and the preliminary characterization of potentially contaminated sites.

Topics: Agriculture; Benzofurans; China; Dioxins; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Islands; Soil

Are the levels of biologically active and the most toxic dioxin-like substances in adipose tissue of patients with deep infiltrating endometriosis (DIE) higher than in a control group without endometriosis?. DIE patients have higher levels of dioxins and polychlorinated biphenyls (PCBs) in adipose tissue compared with controls without endometriosis.. Some studies have investigated the levels of dioxin-like substances, in serum samples, in patients with endometriosis, with inconsistent results.. Case-control study including two groups of patients. The study group (DIE group) consisted of 30 patients undergoing laparoscopic surgery because of DIE. In all patients, an extensive preoperative work-up was performed including clinical exploration, magnetic resonance imaging (MRI) and transvaginal sonography. All patients with DIE underwent a confirmatory histological study for DIE after surgery. The non-endometriosis control group (control group), included the next consecutive patient undergoing laparoscopic surgery in our center due to adnexal benign gynecological disease (ovarian or tubal procedures other than endometriosis) after each DIE patient, and who did not present any type of endometriosis.. During the surgical procedure 1-2 g of adipose tissue from the omentum were obtained. Dioxin-like substances were analyzed in adipose tissue in DIE patients and controls without endometriosis.. The total toxic equivalence and concentrations of both dioxins and PCBs were significantly higher in patients with DIE in comparison with the control group (P < 0.05), mainly due to the significantly higher values of the two most toxic dioxins (2,3,7,8-tetrachlorodibenzo-p-dioxin [2,3,7,8-TCDD] and 1,2,3,7,8-pentachlorodibenzo-p-dioxin [1,2,3,7,8-PeCDD]) (P < 0.01 for each compound). The levels of furan 2,3,4,7,8-PeCDF were statistically higher in the DIE group compared with controls. Only four congeners of PCBs had toxic equivalence values and concentrations that were statistically higher in patients with DIE, but these included the most toxic and carcinogenic PCB-126 (PCB-114 P < 0.05; PCB-156 P < 0.05; PCB-189 P = 0.04; PCB-126 P < 0.01).. Since few patients were recruited, the study is only exploratory. Our results need to be confirmed in larger and more heterogeneous population studies since environmental and even genetic factors involved in determining dioxins and PCBs widely vary in different countries. Furthermore, the strict eligibility criteria used may preclude generalization of the results to other populations and the surgery-based sampling frame may induce a selection bias. Finally, adipose tissue was obtained only from the omentum, and not from other adipose tissue of the body.. Our results suggest a potential role of dioxin-like substances in the pathogenesis of DIE. Further studies are warranted to confirm our findings.. None.. Not applicable.

Topics: Adipose Tissue; Adolescent; Adult; Benzofurans; Body Mass Index; Case-Control Studies; Dioxins; Endometriosis; Female; Humans; Laparoscopy; Limit of Detection; Magnetic Resonance Imaging; Polychlorinated Biphenyls; Ultrasonography; Vagina; Young Adult

The formation and environmental release of highly toxic organohalogen compounds associated with informal recycling of waste electric and electronic equipment (e-waste) is a growing problem at e-waste dumps/recycling sites (EWRSs) in many developing countries worldwide. We chose a cross-sectional study design to measure the internal exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as polychlorinated biphenyls (PCBs) of individuals working on one of the largest EWRSs of Africa, located at Agbogbloshie, Accra, Ghana, and in controls from a suburb of Accra without direct exposure to EWRS activities. In whole blood samples of 21 age matched male exposed individuals (mean age: 24.7 years, SD 6.0) and 21 male controls (mean age: 24.4 years, SD 5.7) 17 PCDD/F congeners were determined. Moreover three indicator PCB congeners (#138, #153 and #180) were measured in blood of 39 exposed (mean age: 27.5 years, SD 11.7) and 19 non-exposed (mean age: 26.8 years, SD 9.7) patients. Besides a health examination, biometric and demographic data, residential and occupational history, occupational exposures and working conditions were recorded using a standardized questionnaire. In the exposed group, median PCDD/F-concentrations were 6.18 pg/g lipid base WHO2005-TEq (range: 2.1-42.7) and significantly higher compared to the control group with 4.60 pg/g lipid base WHO2005-TEq (range: 1.6-11.6). Concentrations were different for 2,3,7,8-TetraCDD, three HexaCDD and all 10 PCDF congeners, indicating a combustion pattern. Using a multivariate regression analysis exposure to EWRS activities was the most important determinant for PCDD/F exposure. Median PCB levels for the indicator congeners #138, #153 and #180 were 0.011, 0.019 and 0.008 μg/l whole blood (ranges: 0.002-0.18, 0.003-0.16, 0.002-0.078) in the exposed group and, surprisingly, significantly higher in the controls (0.037, 0.062 and 0.022; ranges: 0.005-0.46, 0.010-0.46, 0.004-0.21). In a multivariate regression approach e-waste related activities had no positive influence on internal PCB exposure, but rather the time living in Accra. The internal PCB exposure is in particular notable for a country where PCBs have historically never been produced or used. The impact of EWRS activities on organohalogen compound exposure of individuals working at and living in the surroundings of the Agbogbloshie EWRS, and the surprisingly high PCB exposure of people living in Accra not involved in e-waste act

Topics: Adult; Benzofurans; Biphenyl Compounds; Case-Control Studies; Cross-Sectional Studies; Dioxins; Electronic Waste; Environmental Pollutants; Female; Ghana; Humans; Male; Middle Aged; Multivariate Analysis; Occupational Exposure; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Recycling; Young Adult

Sewage sludge samples collected from 43 different domestic and industrial wastewater treatment plants and petrochemical industries that discharge to the Houston Ship Channel (HSC) were analyzed for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), which are highly toxic and carcinogenic towards humans and animals. The measured total PCDD/F toxic equivalency (TEQ) ranged between 0.73 and 7348.40 pg/g dry weight. The mean TEQ of PCDD/Fs in industrial sludge was approximately 40 times higher than that in sewage sludge. The PCDD homolog concentrations in the industrial samples were higher than those observed at the wastewater treatment plants by a factor of 10, with total heptachlorodibenzodioxin (HpCDD) exhibiting the maximum concentration in most of the samples. Among the PCDF homologs, total heptadichlorodibenzofuran (HpCDF) dominated the total homolog concentration in sludge from the wastewater treatment plants, whereas total tetradichlorodibenzofuran (TeCDF) dominated the industrial sludge samples. Overall, the total PCDD/F TEQ in sludge samples was much higher than that in effluent samples from the same facility. A linear correlation (R (2) = 0.62, p value < 0.068) was found indicating that sludge sampling can be used as a surrogate for effluent concentrations in wastewater treatment plants but not for industrial discharges.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Humans; Industrial Waste; Polychlorinated Dibenzodioxins; Sewage; Wastewater; Water Pollutants, Chemical

In this study, the removal efficiency of 136 tetra- to octa-chlorinated dibenzo-p-dioxin (CDD)/furan (F) congeners from a nitrogen + oxygen carrier gas was studied using a laboratory-scale, fixed bed adsorption system. Two kinds of activated carbon with dissimilar pore structures were used as adsorbents. The total concentration of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in the source gas was 541 ng/Nm(3) and that of the 17 toxic 2,3,7,8-substituted PCDD/Fs 96.35 ng/Nm(3), accounting for 17.8% of the total original weight amount. Their toxic equivalent quantity (TEQ) was 8.31 ng I-TEQ/Nm(3). For both activated carbons, the removal efficiencies of the ten PCDD/F homologue groups rise with chlorine substitution number. The removal efficiencies vary approximately as a power function of vapor pressure (correlation coefficients r(2) = 0.93 and 0.81, respectively). Competitive adsorption and desorption occur as adsorption time went on, causing elution of the lower chlorinated homologues, i.e. tetra-CDD/F and Penta-CDD/F congeners. In addition, there are significantly different concentration distributions for isomers in the same homologue groups. However, their removal efficiencies have weak correlation with their initial concentrations. The correlation coefficients are from -0.47 to 0.32 and from -0.57 to 0.46 respectively for the two kinds of activated carbons.

Topics: Adsorption; Benzofurans; Charcoal; Dioxins; Environmental Pollutants; Polychlorinated Dibenzodioxins

This contribution investigates mechanistic and kinetic parameters pertinent to formation of mixed dibenzo-p-dioxins and dibenzofurans (PXDD/Fs) from the condensation reactions involving 2-chlorophenoxy (2-CPxy) and 2-bromophenoxy (2-BPxy) radicals. Keto-ether structures act as direct intermediates for the formation of DD, 1-MCDD, 1-MBDD, 1-B,6-CDD and 1-B,9-CDD molecules. Likewise, diketo adducts initiate the formation of 4-MCDF, 4-MBDF and 4-B,6-CDF compounds through interconversion and rearrangement reactions. As formation mechanisms of halogenated dibenzo-p-dioxins and dibenzofurans from precursors of brominated and chlorinated phenols are insensitive to substitution at meta and para sites, our mechanistic and kinetic analysis of reactions involving 2-BPxy and 2-CPxy should also apply to higher halogenated phenoxy radicals.

Topics: Benzofurans; Dioxins; Environmental Pollutants; Halogenation; Hydrocarbons, Halogenated; Kinetics; Models, Chemical; Molecular Structure; Phase Transition; Phenols

Copper dichloride is an important catalyst both in the dechlorination of chlorinated aromatic compounds and the formation of PCDD/Fs. The effect of copper dichloride on polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) was studied in treated soil and off gas after thermal desorption of PCB-contaminated soil at 300, 400, 500, 600 °C. The presence of copper dichloride clearly enhances thermal desorption by promoting PCBs removal, destruction, and dechlorination. After thermal treatment at 600 °C for 1 h, the removal efficiency and destruction efficiency for PCBs reached 98.1 and 93.9%, respectively. Compared with the positive influence on PCBs, copper dichloride catalyzed large amount of PCDFs formation at 300 °C, with the concentration ratio of 2.35. The effect of CuCl2 on PCDFs formation weakened with the rising temperature since PCDFs destruction became dominant under higher temperature. Different from PCDFs, PCDDs concentration in treated soil and off gas decreased continuously with the increasing temperature.

Topics: Benzofurans; Copper; Dibenzofurans, Polychlorinated; Dioxins; Environmental Pollution; Hot Temperature; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Soil; Soil Pollutants

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were estimated for different particle size distributions in a carbon black feeding process at a tire manufacturing plant on 15 days in March and April of 2014. A total of 75 integrated air samples were collected using a micro-orifice uniform deposition impactor (MOUDI). Particle-bound PCDD/Fs were analyzed using a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Concentrations of thoracic particles and total particles produced in the carbon black feeding process of a tire manufacturing plant were measured in ranges of 0.19-2.61 and 0.28-4.22 mg/m(3), respectively. On all sampling days, the three most abundant species of PCDD/Fs were OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF. The mean concentrations of total PCDD/Fs were 0.74-6.83 pg/m(3) within five particle size ranges. Total I-TEQ in particulate matter (PM)<1.0 was 2.2 and 3.2 times higher than those in PM>18 and PM2.5-10, respectively. However, the total I-TEQ of thoracic PM contributed approximately 74 % of the total I-TEQ of total PM. The assessment of health risk indicates that exposure to fractions of thoracic PM by inhalation poses a significant cancer risk (>10(-6)).

Topics: Air Pollutants; Air Pollution; Benzofurans; Dioxins; Gas Chromatography-Mass Spectrometry; Industry; Particulate Matter; Soot

During this study wipe sampling was applied to various impervious surfaces for the determination of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) area concentrations. To that end, a wipe sampling method based on solvent wetted cotton wipes was evaluated and transfer efficiencies of PCBs and PCDD/PCDFs in particulate films (PFs) and oily liquid films (OFs) during sampling were investigated. For PFs sufficient transfer efficiencies of low concentrated PCB and PCDD/PCDF congeners in 1g/m(2) spiking surrogate were achieved after the first wipe using n-hexane as wetting solvent. Transfer efficiencies for OFs were the highest in the first wipe if n-hexane or n-heptane were used rather than toluene. The spiking experiments of OFs showed a log-linear correlation between the number of wiping procedures and transfer efficiency which indicates that transfer efficiencies were constant in subsequent wipes. Furthermore, it was successfully demonstrated that pressurized liquid extraction is a suitable tool for the extraction of wipe samples. Finally, the feasibility of this wipe sampling method was demonstrated on various impervious surfaces of different origin, and concentration levels of PCBs and PCDD/PCDFs in wipe samples are discussed. Hereby, remarkably high ∑CB6 concentrations of up to 1400μg/m(2) (taken at a transformer recycling site) were detected.

Topics: Air Pollutants; Benzofurans; Dioxins; Environmental Monitoring; Polychlorinated Biphenyls

Plastics from cathode ray tube (CRT) casings were sampled in Nigeria and analysed for their polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) content. PBDD/Fs, consisting mainly of PBDFs, were detected in BFR containing plastic with a median (mean) concentration of 18,000 ng/g (41,000 ng/g). The PBDD/Fs levels were highest in samples containing PBDEs, but the levels of PBDFs were two orders of magnitude higher than the levels reported in the technical PBDE mixtures and where frequently exceeding 1000 μg/g of PBDE content. These higher levels are likely to arise from additional transformation of PBDEs during production, use, recycling, or storage, but the processes responsible were not identified in this study. PBDD/Fs in CRT casings containing1,2-bistribromophenoxyethane (TBPE) were dominated by tetrabrominated dibenzo-p-dioxin (TBDDs) with concentrations around 10 μg/g of the TBPE content. The PBDD/Fs in CRT casings containing tetrabromobisphenol A (TBBPA) were found at concentrations around 0.1 μg/g of TBBPA levels. Casings treated with TBPE or TBBPA often contained PBDEs (and PBDF) as impurities-probably originating from recycled e-waste plastics. It was estimated that the 237,000 t of CRT casings stockpiled in Nigeria contain between 2 and 8 t of PBDD/Fs. The total PBDD/F contamination in polymers arising from total historic PBDE production/use is estimated in the order of 1000 t. TEQ values of CRT samples frequently exceeded the Basel Convention's provisional low POPs content of 15 ng TEQ/g. Due to the significant risks to health associated with PBDD/Fs, more detailed studies on the exposure routes from PBDD/Fs in stockpiles are needed.

Topics: Benzofurans; Dioxins; Electronic Waste; Environmental Monitoring; Environmental Pollutants; Halogenation; Humans; Nigeria; Plastics

Hazardous Air Pollutants (HAPs) such as exhaust particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxide (NOx), mercury (Hg) and polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans ( PCDD/Fs) are emitted by the process of cremation and the burning of oblation. Risks to health posed by emissions of hazardous air pollutants from crematories are emerging concerns. Through field investigation and data collection, we obtained the related activity levels and monitored the concentrations of air pollutants from typical cremators, so as to better understand the current pollutants emission levels for crematory. Using the emission factor method, we calculated the emission inventory of HAPs for crematory of Beijing in 2012 and quantified the range of uncertainty. Using atmospheric diffusion model ADMS, we evaluated the influence of crematories on the surrounding environment, and identified the characteristics of air pollution. The results showed that: for the cremators installed with flue gas purification system, the emission concentration of exhaust PM was rather low, and the CO emission concentration fluctuated greatly. However, relative high emission concentrations of PCDD/Fs were detected mainly due to insufficient combustion. Exhaust PM, CO, SO2, NOx, Hg and PCDD/Fs emitted by crematory of Beijing in 2012 were estimated at about 11. 5 tons, 41.25 tons, 2.34 tons, 7.65 tons, 13.76 kg and 0.88 g, respectively; According to the results of dispersion model simulation, the concentration contributions of exhaust PM, CO, SO2, NOx, Hg, PCDD/Fs from crematories were 0.05947 microg x m(-3), 0.2009 microg x m(-3) and 0.0126 microg x m(-3), 0.03667 microg x m(-3) and 0.06247 microg x m(-3), 0.004213 microg x m(-3), respectively.

Topics: Air Pollutants; Benzofurans; China; Cities; Cremation; Dioxins; Environmental Monitoring; Hazardous Substances; Mercury; Particulate Matter; Sulfur Dioxide; Vehicle Emissions

To explore the levels and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in airborne fine particulate matter (PM25) in Shenzhen and roughly discuss its correlations between PM25 concentration and meteorological factors.. The high volume air samplers were used to collect the samples in six sampling sites in respective winter and spring phase and summer and autumn phase. Referring to the US EPA TO-9A for dioxins detection methods, the concentrations of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans in airborne fine particulate matter were determined by HRGC/HRMS.. The total concentrations of PCDD/Fs ranged from 0.32 to 9.35 pg/m3, with average of 2.45 pg/ m3. The TEQ concentrations ranged from 0.006 to 0.388 pg I-TEQ/m3, with average of 0.095 pg I-TEQ/m3. The four abundant congeners were found to be OCDD (36.49%), 1, 2, 3, 4, 6, 7, 8-HpCDF (14.89%), OCDF (13.34%) and 1, 2, 3, 4, 6, 7, 8-HpCDD (10.92%). 2, 3, 4, 7, 8-PeCDF was the dominant contributor to toxicity equivalent (TEQ), accounting for 34.65%. Positive relationship was found between the levels of fine particle-bound PCDD/Fs and PM2.5 concentration (r(s) = 0.794, P = 0.006), whereas no correlation was observed for temperature, humidity and atmospheric pressure. Inhalation exposure to PCDD/Fs were 0. 023 pg I-TEQ/(kg · d) for adult and 0.035 pg I-TEQ/(kg · d) for children during winter and spring and relatively higher than those during summer and autumn (0.014 pg I-TEQ/(kg · d). for adult and 0.021 pg I-TEQ/(kg · d) for children respectively).. The levels of PCDD/Fs in airborne fine particle-bound samples collected in Shenzhen were lower than those in Hangzhou and Beijing.

Topics: Adult; Benzofurans; Child; China; Dioxins; Humans; Particulate Matter; Polychlorinated Dibenzodioxins; Risk Assessment

To analyze the contamination levels and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fish samples in Shenzhen areas of China, and to reveal the status of PCDD/Fs pollution for fish samples in a decade.. The fish samples including freshwater and saltwater fishes, were collected and analyzed from 2004 to 2013, and PCDD/Fs were detected by isotope dilution HRGC/HRMS using multiple ion detection mode (MID), which was an advanced and authority technique referenced US EPA1613 method.. The average concentration of PCDD/Fs in fish was 0.90 pg/(g wet weight), and the average total toxicity equivalency factor (TEQ) calculated on the basis of the toxic equivalency factor (TEF) published by the World Health Organization (WHO) in 2005 was 0.088 pg WHO-TEQ/(g, wet weight). PCDD/Fs levels in fishes varied widely depending on the species. The PCDD/Fs average contamination levels of fish in 10 years did not exceeded the limit standards of European Commission. The evaluation dietary intake of PCDD/Fs from fish for local residents was 4.80 pg WHO-TEQ/(kg · BW · m).. The PCDD/Fs levels in fish in a decade was less than the maximum limit standards set by European Commission 2011.

Topics: Animals; Benzofurans; Biological Assay; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollution; Fishes; Food Analysis; Fresh Water; Nutrition Assessment; Water Pollutants, Chemical

Human activities are emitting persistent organic pollutants (POPs) to the environment. These compounds have raised concerns about the risk of transfer through the food chain via animal products. They are characterized by a strong persistence in environmental matrices and a lipophilicity which may lead to their accumulation in fat tissues. In EU Regulations (no. 1881/2006, 1259/2011), maximum acceptable levels for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like or nondioxin-like polychlorinated biphenyls (PCBs) in food of animal origin have been set. Transfer rates from contaminated fodder to milk have been established: for PCBs, the rate of transfer varies from 5 to 90% and for PCDD/Fs from 1 to 40%. The differential transfer of the compounds towards milk is related to the hydrophobicity of the pollutants and to their metabolic susceptibility. According to numerous authors, soil is the major reservoir for POPs, and its involuntary ingestion by farm animals reared outdoors may be the main cause of animal product contamination (meat, milk, or eggs). Recent studies seem to indicate that soil is a real risk matrix in terms of transfer of pollutants to the food chain. A POP crisis management is extremely difficult, since it impacts many farmers located in the contaminated area. The question arising is to know if livestock contaminated by POPs may be decontaminated and further used for their initial purpose. Recent data demonstrate that the decontamination process appear feasible and depends on initial level of contamination or the physiological status of the animals.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Eggs; Food Chain; Hazardous Substances; Herbivory; Meat; Milk; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Ruminants; Soil; Soil Pollutants

Bivalve samples from 142 sites were analyzed to determine the concentration and toxicity equivalents (TEQ) of dioxins and furans (D/F) as part of the NOAA National Status and Trends Program. The total concentration of 17 D/F ranged from not detected to 203 pg/g wet weight of tissue. Octachlorinated dibenzo-p-dioxin, OCDD, had a concentration range from not detected to 189 pg/g and a mean concentration of 8.65 pg/g. OCDD was the dominant D/F compound detected and accounted for, on average, over 70% of the total D/F concentration. The TEQ (compared to 2,3,7,8-TCDD) ranged from 0.12 to 7.32 pg TEQ/g. The TEQ for 39% of the bivalves analyzed were below 0.238 pg TEQ/g. TEQ above human consumption advisory concentration of 1.2 pg TEQ/g were found in 9.3% of the samples analyzed. TEQ for D/F indicate very limited human health concerns from consumption of bivalves at most of the locations sampled.

Topics: Animals; Benzofurans; Bivalvia; Dioxins; Humans; Polychlorinated Dibenzodioxins; Water Pollutants, Chemical; Water Pollution, Chemical

We measured serum concentrations of seven dibenzo-p-dioxin congeners (PCDDs), ten dibenzofurans (PCDFs), four non-ortho polychlorinated biphenyls (noPCBs) and six mono-ortho polychlorinated biphenyls (moPCBs) in 1950 veterans of the Vietnam War. The veterans were participants in the Air Force Health Study (AFHS) who attended the final medical examination in 2002. Blood samples were collected from 777 Ranch Hands involved in the aerial spraying of herbicides in Vietnam and a comparison group of 1173 veterans ("Comparisons") who served in Southeast Asia during the same time period. Results for moPCBs were based on a random subsample of 800 veterans. The median 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations in 2002 were 5.0 pg g(-1) lipid in Ranch Hands and 2.2 pg g(-1) lipid in Comparisons. No substantial differences were found in measured concentrations of other PCDDs, PCDFs, and noPCBs. Similarly, no substantial differences were found for moPCBs in the subsample. The median total dioxin toxic equivalent (TEQ) in Ranch Hands was 18.7 pg g(-1) lipid for PCDDs, 3.4 pg g(-1) lipid for PCDFs, and 3.2 pg g(-1) lipid for noPCBs. Median TEQs in Comparisons were 14.4 pg g(-1) lipid for PCDDs, 3.5 pg g(-1) lipid for PCDFs, and 3.3 pg g(-1) lipid for noPCBs. These TEQs, with the exception of PCDD TEQ in Ranch Hands (primarily due to elevated TCDD), were similar to or lower than those reported for similar age and gender groups in the 2001-2002 National Health and Nutrition Examination Survey (NHANES). These findings support the assumption that the Ranch Hand veterans were not more highly exposed to dioxin-like compounds other than TCDD than were Comparison veterans or the general US population.

Topics: Aged; Aged, 80 and over; Benzofurans; Dioxins; Herbicides; Humans; Male; Middle Aged; Military Personnel; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Veterans; Vietnam; Vietnam Conflict

In developing countries such as China, there is a strong need for simple and rapid bioassays for the determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in environmental samples; i.e., flue gas and fly ash from waste incinerators. In this study, we applied the DR-EcoScreen cell (DR-cell) assay to determination of PCDD/Fs in 78 flue gas samples obtained from various waste incinerators in China between 2009 and 2011. The flue gas samples were obtained from four kinds of incinerators, classified into hazardous, medical and municipal-solid waste, and iron ore sintering, and the flue gas extracts were cleaned up using an SPD-600 automated-sample preparation device for DR-cell assay. The PCDD/Fs values obtained from the DR-cell assay were compared with those obtained from conventional high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) analysis. The bioanalytical equivalent (BEQ) values obtained from the DR-cell assay were very closely correlated with the international toxicity equivalent (I-TEQ) values from HRGC-HRMS analysis (r2=0.98, n=78), while the BEQ values were 5.52-fold higher than the I-TEQ values, as the PCDFs, which account for 80% of the total I-TEQ value, were overestimated by DR cell-assay. Therefore, we multiplied the BEQ values from the DR-cell assay by a conversion coefficient (0.181, the reciprocal of 5.52), and could approximate the TEQ values from the HRGC-HRMS analysis. These results suggest that the DR-cell assay combined with SPD-600 cleanup provides a promising method for the simple and rapid screening of PCDD/Fs levels in flue gas samples, such as those from various waste incinerators in China.

Topics: Animals; Benzofurans; Biological Assay; Cell Line; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Gases; Humans; Incineration; Mice; Polychlorinated Dibenzodioxins

A total of 126 food samples, categorised into three groups (seafood and seafood products, meat and meat products, as well as milk and dairy products) from Malaysia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The concentration of PCDD/Fs that ranged from 0.16 to 0.25 pg WHO05-TEQ g(-1) fw was found in these samples. According to the food consumption data from the Global Environment Monitoring System (GEMS) of the World Health Organization (WHO), the dietary exposures to PCDD/F from seafood and seafood products, meat and meat products, as well as milk and dairy products for the general population in Malaysia were 0.064, 0.183 and 0.736 pg WHO05-TEQ kg(-1) bw day(-1), respectively. However, the exposure was higher in seafood and seafood products (0.415 pg WHO05-TEQ kg(-1) bw day(-1)) and meat and meat products (0.317 pg WHO05-TEQ kg(-1) bw day(-1)) when the data were estimated using the Malaysian food consumption statistics. The lower exposure was observed in dairy products with an estimation of 0.365 pg WHO05-TEQ kg(-1) bw day(-1). Overall, these dietary exposure estimates were much lower than the tolerable daily intake (TDI) as recommended by WHO. Thus, it is suggested that the dietary exposure to PCDD/F does not represent a risk for human health in Malaysia.

Topics: Benzofurans; Dioxins; Eating; Environmental Pollutants; Food; Food Analysis; Food Contamination; Humans; Malaysia

Sediment cores from Xingyun Lake close to the pulp mill region of Jiangchuan (China), earlier found to be highly contaminated by pulping at least from the 1990s, were analyzed by HRGC/HRMS for the concentrations of 17 polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). Regarding the contribution of individual congeners, PCDD/F levels ranged from ND (non-detectable) to 82.05 pg g(-1) dw (from ND to 0.16 pg WHO-TEQ g(-1) dw) in 0-20 cm of sediment and from ND to 45.61 pg g(-1) dw (from ND to 0.67 WHO-TEQ g(-1) dw) in 20-40 cm of sediment for 17 PCDD/Fs (WHO-TEQ: WHO-endorsed toxic equivalents). Major PCDD/Fs identified and confirmed were high-chlorinated congeners including OCDD/Fs and HpCDD/Fs in the two depths. For high-chlorinated PCDD/Fs such as O, Hp-CDD/Fs across the depth of sediment, sediment had a higher proportion in 0-20 cm than that in 20-40 cm. On the contrary, for low-chlorinated PCDD/Fs such as T, Pe, Hx-CDD/Fs, the lower proportion was found in 0-20 cm. The results demonstrated that PCDD/Fs loads in the sediment of Xingyun Lake were very low compared to loads in the other regions about 8 years after closedown of a majority of pulp production with chlorine, which indicated that pulp production was an important emission source of dioxins.

Topics: Benzofurans; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Geologic Sediments; Lakes

The levels and specific profiles of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in Mytilus galloprovincialis from the Mar Grande and the Mar Piccolo of Taranto were determined during the extensive monitoring plan of Local Health Authority to assess PCDD/Fs and DL-PCBs contamination in food and farm products, within 20 km from the industrial areas of Taranto, between March and December 2011. The average Total Toxicity Equivalence (TEQ) values for the sum of PCDD/F and DL-PCBs ranged from 1.61 to 5.63 pg WHO2005-TEQ g(-1) wet weight basis, with the highest in the first inlet of the Mar Piccolo. In particular, DL-PCBs were the dominant chemicals in all samples, followed by PCDFs and PCDDs. Congener patterns in mussels were similar, indicating a homogeneous behavior in studied areas and, probably, the same type of source. The seasonal concentrations trend showed a relevant increase of dioxin and dioxin-like PCBs TEQs during the summer months, exceeding the limits set by the European Community for food and foodstuff. Reducing PCDD/Fs and PCBs is necessary to decrease contamination levels in order to safeguard marine ecosystem and human health in the Taranto area.

Topics: Animals; Benzofurans; Dioxins; Food Contamination; Humans; Italy; Mediterranean Sea; Mytilus; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Seasons

More than 300 samples of human milk were collected from individuals residing in various regions across Canada in the years 1992 to 2005. The milks were taken from the main populated areas east to west in southern Canada as well as from the region of Nunavik in northern Quebec and analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). The concentrations, expressed in ng kg(-1) milk lipid, show an overall decrease of virtually all compounds examined including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), World Health Organization 2005 toxic equivalents (WHO2005-TEQ) PCDD/PCDFs, WHO2005-TEQ dioxin-like PCBs (dl-PCBs), and total PCBs. Median values of 2,3,7,8-TCDD changed from about 1.5 ng kg(-1) milk lipid in 1992 to 0.8 ng kg(-1) in 2005 while the median WHO2005-TEQ PCDD/F fell from about 14-7 ng kg(-1) milk lipid in the same period. The concentrations of PCDD/Fs and PCBs in samples from Nunavik, which is in Arctic Quebec, were higher than those observed in milk from southern Quebec although this difference was not large. Over two time periods, milk samples from Hamilton, Ontario showed slightly higher levels of PCBs than Austin, Texas, USA--a North American city of similar size and development but with more than twice the PBDE exposure. When compared with earlier human milk data going back to the early 1980s, this large data set shows a steady decline of human exposure to POPs in Canada by a factor of about four times.

Topics: Adult; Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Female; Furans; Humans; Lipids; Milk, Human; Ontario; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Quebec; Time Factors; World Health Organization

Experimental studies have shown that dioxin-like chemicals may interfere with aspects of the endocrine system including growth. However, human background population studies are, however, scarce. We aimed to investigate whether early exposure of healthy infants to dioxin-like chemicals was associated with changes in early childhood growth and serum IGF1. In 418 maternal breast milk samples of Danish children (born 1997-2001) from a longitudinal cohort, we measured polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls (pg or ng/g lipid) and calculated total toxic equivalent (total TEQ). SDS and SDS changes over time (ΔSDS) were calculated for height, weight, BMI, and skinfold fat percentage at 0, 3, 18, and 36 months of age. Serum IGF1 was measured at 3 months. We adjusted for confounders using multivariate regression analysis. Estimates (in parentheses) correspond to a fivefold increase in total TEQ. TEQ levels in breast milk increased significantly with maternal age and fish consumption and decreased with maternal birth year, parity, and smoking. Total TEQ was associated with lower fat percentage (-0.45 s.d., CI: -0.89; -0.04), non-significantly with lower weight and length at 0 months, accelerated early height growth (increased ΔSDS) (ΔSDS 0-18 months: +0.77 s.d., CI: 0.34; 1.19) and early weight increase (ΔSDS 0-18: +0.52 s.d., CI: 0.03; 1.00), and increased IGF1 serum levels at 3 months (+13.9 ng/ml, CI: 2.3; 25.5). Environmental exposure to dioxin-like chemicals was associated with being skinny at birth and with higher infant levels of circulating IGF1 as well as accelerated early childhood growth (rapid catch-up growth).

Topics: Adult; Benzofurans; Child Development; Denmark; Dibenzofurans, Polychlorinated; Dioxins; Environmental Pollutants; Female; Furans; Humans; Infant; Infant, Newborn; Insulin-Like Growth Factor I; Longitudinal Studies; Male; Maternal Exposure; Milk, Human; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Young Adult

A series of treatment experiments were carried out to evaluate the applicability of a high-temperature melting treatment (GeoMelt process) to the destruction of polychlorinated naphthalene (PCN) formulation. We started with 10-kg-scale experiments in which a small melting furnace was used and then scaled up to a 1-t-scale experiment in which a melting furnace that resembled an actual treatment system was used. These runs were evaluated whether destruction efficiency (DE) of total PCNs was more than 99.999% and whether concentrations of PCNs and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/DFs) in vitrified materials, emission gas, and scrubber water were below the target levels. Because DE values and the target levels of PCNs and PCDDs/DFs in these runs were satisfactory, then we carried out a demonstrative experiment using the actual treatment system and confirmed destruction of PCNs. Based on good results of the demonstrative experiment, stock of PCN formulation was successfully treated continuously.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Equipment Design; Hot Temperature; Incineration; Naphthalenes; Polychlorinated Biphenyls

Tests were conducted to study the removal efficiencies (REs) of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from flue gas during a test program involving a pilot-scale catalytic filter (CF) module and a full-scale municipal solid waste incinerator (MSWI). The REs attained with the CF on a side stream and a conventional activated carbon (AC) injection and baghouse filtration system in the full-scale MSWI are evaluated via simultaneous sampling and analysis of both gas- and particle-phase PCDD/Fs. Flue gas without AC is supplied to the pilot-scale CF module for evaluating its RE capabilities. The REs achieved with the CF at 180 °C are 96.80 and 99.50%, respectively, for the gas phase and the particulate contained. The gas-phase PCDD/F RE rises significantly at 200 and 220 °C. The air/cloth (A/C) ratio defined as is the gas flow rate (m(3)/min) divided by the filtration area (m(2)) also affects the PCDD/F RE, especially in the gas phase. At 180 °C, a RE of gas-phase PCDD/Fs of 95.94% is attained with the CF at 0.8 m/min, yet it decreases at higher A/C ratios (1 and 1.2 m/min). A significantly lower toxic equivalency (TEQ) concentration (0.71 ng I-TEQ/g) was measured in the filter dust of the CF module compared to that collected by the AC adsorption system (4.18 ng I-TEQ/g), apparently because of the destruction of gas-phase PCDD/Fs by the catalyst.

Topics: Adsorption; Benzofurans; Catalysis; Charcoal; Cities; Dibenzofurans, Polychlorinated; Dioxins; Filtration; Gases; Incineration; Pilot Projects; Solid Waste

Dioxin levels in the breast milk of mothers residing near a contaminated former airbase in Vietnam remain much higher than in unsprayed areas, suggesting high perinatal dioxin exposure for their infants. The present study investigated the association of perinatal dioxin exposure with autistic traits in 153 3-year-old children living in a contaminated area in Vietnam. The children were followed up from birth using the neurodevelopmental battery Bayley-III. The high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposed groups (⩾3.5 pg per g fat) showed significantly higher Autism Spectrum Rating Scale (ASRS) scores for both boys and girls than the mild-TCDD exposed groups, without differences in neurodevelopmental scores. In contrast, the high total dioxin-exposed group, indicated by polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs)--the toxic equivalents (TEQ) levels⩾17.9 pg-TEQ per g fat, had significantly lower neurodevelopmental scores than the mild-exposed group in boys, but there was no difference in the ASRS scores. The present study demonstrates a specific impact of perinatal TCDD on autistic traits in childhood, which is different from the neurotoxicity of total dioxins (PCDDs/Fs).

Topics: Autistic Disorder; Benzofurans; Child Development; Child, Preschool; Cohort Studies; Dioxins; Dose-Response Relationship, Drug; Female; Follow-Up Studies; Humans; Male; Maternal Exposure; Milk, Human; Polychlorinated Dibenzodioxins; Psychiatric Status Rating Scales; Sex Factors; Vietnam

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDF) were overall measured and compared in ambient air, water, soils, and sediments along the upper reaches of the Haihe River of North China, so as to evaluate their concentrations, profiles, and to understand the processes of gas-particle partitioning and air-water/soil exchange. The following results were obtained: (1) The average concentrations (toxic equivalents, TEQs) of 2,3,7,8-PCDD/PCDF in air, water, sediment, and soil samples were 4,855 fg/m(3), 9.5 pg/L, 99.2 pg/g dry weight (dw), and 56.4 pg/g (203 fg TEQ/m(3), 0.46 pg TEQ/L, 2.2 pg TEQ/g dw, and 1.3 pg TEQ/g, respectively), respectively. (2) Although OCDF, 1,2,3,4,6,7,8-HpCDF, OCDD, and 1,2,3,4,6,7,8-HpCDD were the dominant congeners among four environmental sinks, obvious discrepancies of these congener and homologue patterns of PCDD/PCDF were observed still. (3) Significant linear correlations for PCDD/PCDF were observed between the gas-particle partition coefficient (K p) and the subcooled liquid vapor pressure (P L (0)) and octanol-air partition coefficient (K oa). (4) Fugacity fraction values of air-water exchange indicated that most of PCDD/PCDF homologues were dominated by net volatilization from water into air. The low-chlorinated PCDD/PCDF (tetra- to hexa-) presented a strong net volatilization from the soil into air, while high-chlorinated PCDD/PCDF (hepta- to octa-) were mainly close to equilibrium for air-soil exchange.

Topics: Atmosphere; Benzofurans; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollutants; Mass Spectrometry; Rivers; Soil; Volatilization

Fluorine-containing halogenated fluorophenol may have effect as intermediate species involved in the formation of polyfluorinated dibenzo-p-dioxin/dibenzofurans (PFDDs/Fs). The mechanism for the atomic H initiated reactions with complete series of nineteen fluorophenol congeners was studies using the density functional theory. At the MPWB1K/6-31+G(d,p) level, the geometries and frequencies of reactants, transition states, and products were obtained, and the accurate energetic values were acquired at the MPWB1K/6-311+G(3df,2p) level. The rate constants were evaluated by the canonical variational transition-state theory with the small curvature tunneling contribution over a wide temperature range of 600-1000 K. The study shows that the intramolecular hydrogen-bond in the ortho-substituted FPs as well as the inductive effect of the electron-withdrawing fluorine and steric repulsion of multiple substitutions may ultimately be responsible for the relative strength of the O-H bonds in FPs. The results can be used for further studies on PFDD/Fs formation mechanism.

Topics: Benzofurans; Chlorophenols; Dioxins; Hydrocarbons, Fluorinated; Hydrogen; Kinetics; Phenols

Chlorine bleaching is still practiced by most of nonwood pulp and paper mills, resulting in a considerable amount of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) formation and emission. In this study, the effects of primary chlorination conditions on the formation of PCDD/Fs from nonwood pulp bleaching with elemental chlorine were investigated. It was found that low-chlorinated PCDD/Fs were usually formed and then underwent further chlorination to form highly chlorinated PCDD/Fs with increasing chlorination time. Higher available chlorine dosages and lower system pH values greatly accelerated dioxin formation, and pH 3 was the threshold for the formation of tetra- to octa-CDD/Fs. Higher temperatures promoted the formation of lower-chlorinated PCDD/Fs, while caused significant reduction of tetra- to hepta-CDDs and penta- to octa-OCDFs. PCDFs were formed much faster than PCDDs. A first-order kinetic model showed a good fit to the data for tetra- to oct-CDFs formation under different chlorination conditions, indicating that chlorine substitution was the rate determining step for their formation. Finally, the optimum chlorination conditions for minimizing and eliminating the formation of 2,3,7,8-TCDD/TCDF in nonwood pulp bleaching with elemental chlorine were established.

Topics: Benzofurans; Chlorine; Dibenzofurans, Polychlorinated; Dioxins; Halogenation; Hydrogen-Ion Concentration; Kinetics; Models, Theoretical; Paper; Polychlorinated Dibenzodioxins; Temperature; Time Factors; Wood

Unintentionally produced persistent organic pollutants (UP-POPs) including polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) were characterized and quantified in stack gas and fly ash from the second ventilation systems in five typical converters in five different steelmaking plants. The 2378-substituted PCDD/Fs (2378-PCDD/Fs) and dioxin-like PCB (dl-PCBs) toxic equivalents (TEQs) were 1.84-10.3 pg WHO-TEQ Nm(-3) in the stack gas and 5.59-87.6 pg WHO-TEQ g(-1) in the fly ash, and the PCN TEQs were 0.06-0.56 pg TEQ Nm(-3) in the stack gas and 0.03-0.08 pg TEQ g(-1) in the fly ash. The concentrations of UP-POPs in the present study were generally lower than those in other metallurgical processes, such as electric arc furnaces, iron ore sintering, and secondary metallurgical processes. Adding scrap metal might increase UP-POP emissions, indicating that raw material composition was a key influence on emissions. HxCDF, HpCDF, OCDF, HpCDD, and OCDD were the dominant PCDD/Fs in the stack gas and fly ash. TeCB and PeCB were dominant in the stack gas, but HxCB provided more to the total PCB concentrations in the fly ash. The lower chlorinated PCNs were dominant in all of the samples. The 2378-PCDD/F, dl-PCB, and PCN emission factors in stack gases from the steelmaking converter processes (per ton of steel produced) were 1.88-2.89, 0.14-0.76, and 229-759 μg t(-1), respectively.

Topics: Air Pollutants; Benzofurans; Coal Ash; Dioxins; Environmental Monitoring; Gases; Hazardous Substances; Metallurgy; Naphthalenes; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

We determined the distribution of polychlorinated biphenyls (PCBs), pentachlorobenzene (PeCBz), hexachlorobenzene (HxCBz), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in surface sediments at 21 sites inside and outside Muroran Port, Japan. The concentration ranges and geometric means of PCBs (Σ209PCB), PeCBz, HxCBz, and PCDD/Fs and toxicity equivalence quantity (total TEQ) of dioxins inside Muroran Port were 1,100-65,000 (mean, 17,000) pg/g dw, 37-220 (100) pg/g dw, 31-810 (84) pg/g dw, 69-410 (170) pg/g dw, and 0.51-6.2 (2.3) pg TEQ/g dw, respectively. Their corresponding inventories inside Muroran Port were estimated to be 76, 0.31, 0.32, 0.55, and 7.8 g TEQ, respectively. The amounts of these pollutants were higher inside the port than outside the port and especially large in the inner part of the port. Most PCBs were homologues and congeners of penta- to hepta-chlorinated compounds, and the PCBs around Muroran Port were derived from technical PCBs, especially KC500 and KC600. As for PCDD/Fs, the influence of pentachlorophenol was significant, although pollution due to chloronitrofen and combustion was detected. The congeners of PCDD/Fs predominantly contributed to total TEQ. The concentration distributions of PeCBz, HxCBz, and PCDD/Fs and total TEQ were highly correlated with one another. This indicates that they are derived from the same combustion process.

Topics: Benzofurans; Chlorobenzenes; Dioxins; Environmental Monitoring; Environmental Pollutants; Geologic Sediments; Hexachlorobenzene; Japan; Polychlorinated Biphenyls

Chlorobenzene (CBz) is the precursor of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) generated in the processes of waste incineration, and it is regarded as a good indicator of PCDD/Fs for realizing PCDD/Fs online monitoring, moreover, pentachlorobenzene (PeCBz) and Hexachlorobenzene (HxCBz) belong to Persistent Organic Pollutants (POPs). However, the emission control of CBz in waste incineration does not attract enough attention, so this study focused on the inhibition of the 3 CBz formation routes in waste combustion by ammonium sulfate and urea, including CB formation from fly ash, CB formation from 1,2-dichlorobenzene (1,2-DiCBz) and the combustion of model medical waste. The results showed that both ammonium sulfate and urea reduced CBz yield during these three thermal processes. For instance, the inhibition rates of tetrachlorobenzene (TeCBz), PeCBz and HxCBz were 66.8%, 57.4% and 50.4%, respectively, when 1% urea was co-combusted with medical waste. By comparing the effect of ammonium sulfate and urea on CBz formation by three routes, urea was considered as a comparatively stable inhibitor for CBz.

Topics: Ammonium Sulfate; Benzofurans; Chlorobenzenes; Coal Ash; Dioxins; Hexachlorobenzene; Incineration; Polymers; Urea

Superficial sediments collected from seven estuarine systems located along the Portuguese coast were analyzed for 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like polychlorinated biphenyls (dl-PCBs). Total PCDD/F concentration ranged from 4.6 to 464 pg g(-1) dry weight (dw), while that of dl-PCBs varied from 26.6 to 8,693 pg g(-1) dw. In general, the highest PCDD/F and dl-PCB concentrations were associated with densely populated and industrially impacted areas. Additionally, PCDD/F revealed a predominance of octachlorodibenzodioxin (OCDD) to total PCDD/Fs, while PCB 118 was the major contributor to total dl-PCBs. This study provided a global perspective of the contamination status of Portuguese estuaries by dioxin-like compounds and allowed a comparison between the investigated systems and other systems worldwide. PCDD/F and dl-PCB levels found in the collected sediments were lower than those of highly impacted areas from different parts of the globe. Nevertheless, comparison with guidelines and quality standards from other countries indicated that some Portuguese estuarine areas with a high industrialization level present PCDD/F and dl-PCB concentrations in superficial sediment that may constitute a risk to aquatic organisms.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Estuaries; Geologic Sediments; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Portugal

Principal component analysis (PCA) was applied for evaluating the selectivity of 22 GC columns for which complete retention data were available for the 136 tetra- to octa-chlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Because the hepta- and octa-homologues are easy to separate the PCA was focused on the 128 tetra- to hexa-CDD/Fs. The analysis showed that 21 of the 22 GC columns could be subdivided into four groups with different selectivity. Group I consists of columns with non-polar thermally stable phases (Restek 5Sil MS and Dioxin 2, SGE BPX-DXN, Supelco Equity-5, and Agilent DB-1, DB-5, DB-5ms, VF-5ms, VF-Xms and DB-XLB). Group II includes ionic liquid columns (Supelco SLB-IL61, SLB-IL111 and SLB-IL76) with very high polarity. Group III includes columns with high-percentage phenyl and cyanopropyl phases (Agilent DB-17 and DB-225, Quadrex CPS-1, Supelco SP-2331, and Agilent CP-Sil 88), and Group IV columns with shape selectivity (Dionex SB-Smectic and Restek LC-50, Supelco βDEXcst, Agilent VF-Xms and DB-XLB). Thus, two columns appeared in both Group I and IV (Agilent VF-Xms and DB-XLB). The selectivity of the other column, Agilent DB-210, differs from those of these four groups. Partial least squares (PLS) regression was used to correlate the retention times of the tetra- to hexa-CDD/Fs on the 22 stationary phases with a set of physicochemical and structural descriptors to identify parameters that significantly influence the solute-stationary phase interactions. The most influential physicochemical parameters for the interaction were associated with molecular size (as reflects in the total energy, electron energy, core-core repulsion and standard entropy), solubility (aqueous solubility and n-octanol/water partition coefficient), charge distribution (molecular polarizability and dipolar moment), and reactivity (relative Gibbs free energy); and the most influential structural descriptors were related to these parameters, in particular, size and dipolar moment. Finally, the PCA and PLS analyses were complemented with linear regression analysis to identify the most orthogonal column combinations, which could be used in comprehensive two-dimensional gas chromatography (GC×GC) to enhance PCDD/F separation and congener profiling.

Topics: Benzofurans; Chromatography, Gas; Dibenzofurans, Polychlorinated; Dioxins; Multivariate Analysis; Polychlorinated Dibenzodioxins; Principal Component Analysis; Regression Analysis; Solubility; Thermodynamics

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in 25 background and 80 agricultural soil samples collected from 21 sites in Beijing, China. The levels of PCDD/Fs in the north agricultural soils were low (0.15-0.58 ng international toxic equivalent quantity [I-TEQ]/kg), which were comparable with those of the background soils (0.091-0.35 ng I-TEQ/kg). In the southern agricultural soils, however, concentrations were several times higher (0.27-3.3 ng I-TEQ/kg). Comparison of PCDD/Fs congener compositions between possible sources and samples indicated that agricultural soils in Beijing had not been contaminated by the 3 main PCDD/F contamination sources in China--ferrous and nonferrous metal, waste incineration, and power generation. They had, however, been slightly contaminated by the impurities of some organochlorine pesticides, such as sodium pentachlorophenate, and by open burning of biomass, vehicle exhaust, atmospheric deposition, sediment, and sewage sludge. These results have been supported by the principal components analysis.

Topics: Agriculture; Benzofurans; China; Dioxins; Environmental Monitoring; Hydrocarbons, Chlorinated; Incineration; Pesticides; Soil; Soil Pollutants

Atmospheric depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were monitored at three sites in the vicinity of a steel making plant, located in an Italian alpine valley. A high variability in the deposition of PCDD/Fs was observed. The influence of the plant was noticeable at two of the sampling sites. However, as the congener profiles demonstrated, wood burning for domestic heating is an additional source of PCDD/Fs for the area under investigation, and this interferes with the characterization of the emissions from the steel plant. The influence of the plant, in terms of PCDD/F deposition, was not noticeable at the most distant site (2km), where an extremely high peak of PCDD/F deposition was measured during the period from 12 January-22 February 2012. The comparison between the congener distribution of PCDD/Fs observed in this sample and the fingerprints of different sources could justify the attribution of this anomalous peak to a possible episode of domestic waste combustion. In order to find a better correlation between the deposition to soil and emissions from the plant, the congener distribution of PCBs was studied. The PCB profiles observed at the three sites well reproduced the average profile found in samples of ash retained by the bag filter of the plant. Thus the monitoring of PCB deposition is an interesting starting point to calibrate dispersion models to assess the impact of steel making activities.

Topics: Air Pollutants; Atmosphere; Benzofurans; Chemical Industry; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Steel

Municipal solid waste incinerators (MSWIs) have long been the major contributors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to ambient air in Taiwan. After stringent MSWI emission standards were introduced in 2001, the long-term continuous monitoring of flue gas and ambient air quality became necessary to ensure the effectiveness of the related control strategies. Three MSWIs and the surrounding ambient air were investigated in the current study for PCDD/F characteristics during 2006 to 2011. The average concentrations in the flue gas ranged from 0.008 ~ 0.0488 ng I-TEQ/Nm(3), which is much less than the emission standard in Taiwan (0.1 ng I-TEQ/Nm(3)) (I-TEQ is the abbreviation of International Toxic Equivalent). This led to extremely low levels in the ambient air, 0.0255 pg I-TEQ/Nm(3), much less than the levels seen in most urban areas around the world. Additionally, the results obtained using the Industrial Source Complex Short-Term Dispersion Model (ISCST3) indicate that the PCDD/F contributions from the three MSWIs to the ambient air were only in the range from 0.164 ~ 0.723 %. Principal component analysis (PCA) showed that the PCDD/Fs in the air samples had very similar characteristics to those from mobile sources. The results thus show that stringent regulations have been an effective control strategy, especially for urban areas, such as Taipei City.

Topics: Air Pollutants; Benzofurans; Dioxins; Environmental Monitoring; Incineration; Models, Theoretical; Solid Waste; Taiwan

On the basis of laboratory experiments with model mixtures (active carbon+CuBr2 at different loads), this work studies the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) by de novo synthesis. For the different samples, the temperature of the maximum carbon oxidation rate was determined by thermogravimetric analysis, and a kinetic model was proposed for the degradation of the materials in an oxidizing atmosphere (synthetic air). The effect of the addition of different amounts of CuBr2 was studied, finding that its presence accelerates the degradation of the carbonaceous structure in the presence of oxygen. The thermal degradation of the samples in air is satisfactorily described by a first-order single-reaction model. In addition, combustion runs of one of the mixtures (consisting of activated carbon+50 wt % CuBr2, pyrolyzed at 700 °C) were performed in a quartz horizontal laboratory furnace. The analysis of the emissions and the solid residue proved the formation of brominated dioxins and furans at 300, 400, and 500 °C, with a maximum yield at 300 °C (91.7 ng/g of total PBDD/Fs) and a higher bromination degree with increasing temperature.

Topics: Benzofurans; Bromides; Charcoal; Copper; Dioxins; Halogenation; Kinetics; Oxidation-Reduction; Temperature

Effective management of contaminated sediments is important for long-term human and environmental health, but site-management decisions are often made under high uncertainty and without the help of structured decision support tools. Potential trade-offs between remedial costs, environmental effects, human health risks, and societal benefits, as well as fundamental differences in stakeholder priorities, complicate decision making. Formal decision-analytic tools such as multicriteria decision analysis (MCDA) move beyond ad hoc decision support to quantitatively and holistically rank management alternatives and add transparency and replicability to the evaluation process. However, even the best decisions made under uncertainty may be found suboptimal in hindsight, once additional scientific, social, economic, or other details become known. Value of information (VoI) analysis extends MCDA by systematically evaluating the impact of uncertainty on a decision. VoI prioritizes future research in terms of expected decision relevance by helping decision makers estimate the likelihood that additional information will improve decision confidence or change their selection of a management plan. In this study, VoI analysis evaluates uncertainty, estimates decision confidence, and prioritizes research to inform selection of a sediment capping strategy for the dibenzo-p-dioxin and -furan contaminated Grenland fjord system in southern Norway. The VoI model extends stochastic MCDA to model decisions with and without simulated new information and compares decision confidence across scenarios with different degrees of remaining uncertainty. Results highlight opportunities for decision makers to benefit from additional information by anticipating the improved decision confidence (or lack thereof) expected from reducing uncertainties for each criterion or combination of criteria. This case study demonstrates the usefulness of VoI analysis for environmental decisions by predicting when decisions can be made confidently, for prioritizing areas of research to pursue to improve decision confidence, and for differentiating between decision-relevant and decision-irrelevant differences in evaluation perspectives, all of which help guide meaningful deliberation toward effective consensus solutions.

Topics: Benzofurans; Decision Making; Decision Support Techniques; Dioxins; Environment; Geologic Sediments; Humans; Information Dissemination; Norway; Probability; Public Health; Stochastic Processes; Uncertainty; Water Pollutants, Chemical; Water Pollution

Unintentionally produced persistent organic pollutants (UP-POPs) were determined in ambient air from around five secondary non-ferrous metal processing plants in China, to investigate the potential impacts of the emissions of these plants on their surrounding environments. The target compounds were polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), and polychlorinated naphthalenes (PCNs). The PCDD/F, dl-PCB, and PCN concentrations in the ambient air downwind of the plants were 4.70-178, 8.23-7520 and 152-4190 pg/m(3), respectively, and the concentrations upwind of the plants were lower. Clear correlations were found between ambient air and stack gas concentrations of the PCDD/Fs, dl-PCBs, and PCNs among the five plants, respectively. Furthermore, the UP-POPs homolog and congener patterns in the ambient air were similar to the patterns in the stack gas samples. These results indicate that UP-POPs emissions from the plants investigated have obvious impacts on the environments surrounding the plants.

Topics: Air Pollutants; Aluminum; Benzofurans; China; Copper; Dioxins; Gases; Metallurgy; Naphthalenes; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

This study aimed to predict the occurrence of four phthalates, two polychlorinated dibenzo-p-dioxins and two polychlorinated dibenzofurans in environmental and agricultural media from observed concentrations in air, sludge, manure and concentrate. For the environmental and agricultural fate modelling, the newly developed multimedia model "EN-forc" (ENvironmental Food transfer model for ORganic Contaminants) was used. To validate EN-forc calculations, the predicted concentrations of the considered chemicals in soil, groundwater, drinking water, plants and animal products were compared with both observed and modelled concentrations available in the literature. For the majority of the considered matrices, predicted phthalate and dioxin levels differed one order of magnitude at most with observed concentrations. Unfortunately, the transfer models implemented in EN-forc lacked power to predict levels of some phthalates and dioxins in pasture, root crops and/or tubers. Concentrations of phthalates and dioxins in offal could not be predicted due to the absence of suitable models that have an acceptable level of complexity to implement in EN-forc. For this type of food products, further research is highly encouraged. In a next step, the modelling framework of EN-forc will be extended in order to be able to predict human dietary exposure to organic chemicals like phthalates and dioxins.

Topics: Agriculture; Animals; Benzofurans; Crops, Agricultural; Dibenzofurans, Polychlorinated; Dioxins; Environmental Pollutants; Humans; Models, Chemical; Phthalic Acids; Polychlorinated Dibenzodioxins; Solubility

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) belong to the group of persistent organic pollutants, highly toxic environmental pollutants that include hydrophobic compounds with the tendency to bioaccumulate. Earthworms (Eisenia andrei) were exposed to PCDD/Fs-contaminated soil, and changes in their lipophilic structures and the gene expression of their defense molecules were followed. Damage to the intestinal wall and adjacent chloragogenous tissue was observed. Further, the up-regulation of the expression of several genes was detected. On the basis of these results, the mechanism of the impact of PCDD/Fs on earthworms has been proposed. Dioxins that accumulate in the lipophilic structures cause an increase in reactive oxidative species that triggers oxidative stress followed by the gene expression of two molecules that play a role in protection against oxidant toxicity, calreticulin (CRT) and Hsp70. Moreover, the effect of microbial biomass on the expression of coelomic cytolytic factor (CCF), a pattern recognition receptor, was also observed.

Topics: Animals; Benzofurans; Dioxins; Gene Expression Regulation; Oligochaeta; Soil; Soil Pollutants

Spatial and temporal trends of sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Baltic Sea were evaluated by positive matrix factorization (PMF) and principal component analysis (PCA). Sediment cores were sampled at eight coastal, one coastal reference, and six offshore sites covering the northern to the southern Baltic Sea. The cores, which covered the period 1919-2010, were sliced into 2-3 cm disks among which 8-11 disks per core (in total 141 disks) were analyzed for all tetra- through octa-CDD/Fs. Identification and apportionment of PCDD/F sources was carried out using PMF. Five stable model PCDD/F congener patterns were identified, which could be associated with six historically important source types: (i) atmospheric background deposition (ABD), (ii) use and production of penta-chlorophenol (PCP), (iii) use and production of tetra-chlorophenol (TeCP), (iv) high temperature processes (Thermal), (v) hexa-CDD-related sources (HxCDD), and (vi) chlorine-related sources (Chl), all of which were still represented in the surface layers. Overall, the last four decades of the period 1920-2010 have had a substantial influence on the Baltic Sea PCDD/F pollution, with 88 ± 7% of the total amount accumulated during this time. The 1990s was the peak decade for all source types except TeCP, which peaked in the 1980s in the northern Baltic Sea and has still not peaked in the southern part. The combined impact of atmospheric-related emissions (ABD and Thermal) was dominant in the open sea system throughout the study period (1919-2010) and showed a decreasing south to north trend (always >80% in the south and >50% in the north). Accordingly, to further reduce levels of PCDD/Fs in the open Baltic Sea ecosystem, future actions should focus on reducing atmospheric emissions.

Topics: Benzofurans; Chlorophenols; Dibenzofurans, Polychlorinated; Dioxins; Ecosystem; Environmental Monitoring; Geologic Sediments; Oceans and Seas; Polychlorinated Dibenzodioxins; Water Pollutants, Chemical

The occurrence of nineteen mixed halogenated (bromo-chloro) dibenzo-p-dioxins, dibenzofurans (PXDD/Fs) and biphenyls (PXBs) in a range of foods (n>100) was investigated. The analytical methodology used dual activated carbon column fractionation with high resolution mass spectrometric measurement (13,500-15,000 res). Occurrence was observed in most commonly consumed foods but the most frequent detections of these environmental contaminants were made in shellfish and offal. The concentrations of the individual compounds were condensed into toxic equivalents (TEQs) using recently reported relative potency values. Although representing only a small subset of the full range of toxic PXDD/Fs and PXBs, the TEQs estimated for these compounds ranged from 0.2% to approximately 15% (depending on the food matrix) of the corresponding TEQ for the fully chlorinated analogues. This finding is of great toxicological importance as it implies that a potentially greater magnitude of TEQ could be associated with the full range of toxic PXDD/Fs and PXBs, thus making a significant contribution to dioxin-like toxicity from the diet, to human exposure.

Topics: Benzofurans; Biphenyl Compounds; Dioxins; Environmental Pollutants; Food Contamination; Furans; Humans; Hydrocarbons, Brominated; Hydrocarbons, Chlorinated; Polychlorinated Dibenzodioxins

In Taiwan, a food safety crisis involving a presence of high concentrations of dioxin residues in duck eggs occurred in 2004. The dioxin content in duck meat sampled from supermarkets was also reported to be substantially higher than in products from other farm animals. Despite increased awareness of the potential for contamination and exposure to dioxins, the accumulation and elimination of dioxins in ducks have not been well characterized. In the present study, mule ducks were fed capsules containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for 14 days and the trial was continued for another 28 days without PCDD/Fs supplementation. Ducks were sacrificed on the 14th, 28th, and 42nd days from the beginning of administration and samples of abdominal fat, breast, and liver tissue were obtained. The concentrations of PCDD/Fs were analyzed in the samples to investigate their distribution and elimination in various duck tissues. The bioaccumulation of PCDD/Fs in ducks was found to be tissue-dependent. In the abdominal fat, the bioconcentration factor was negatively correlated with the degree of chlorination. Conversely, more chlorinated PCDD/Fs (hexa- or hepta-congeners) were associated with higher bioconcentration in the liver and breast tissue. In terms of the efficiency of PCDD/Fs elimination, the liver was found to be the fastest, followed by the breast and the abdominal fat. The clearance rate positively correlated with the degree of chlorination, as determined by comparing the apparent elimination rate constant (k) of PCDD/Fs in various tissues. Overall, lower k values observed in this study imply that mule ducks have a reduced clearance of PCDD/Fs in comparison with layer and broiler chickens.

Topics: Animals; Benzofurans; Dioxins; Ducks; Environmental Pollutants; Taiwan

The coupled physical-biogeochemical model BALTSEM, previously used to assess nutrient/carbon cycles and eutrophication in the Baltic Sea, has been expanded to include algorithms for calculations of organic contaminant environmental transport and fate. This novel model version (BALTSEM-POP) is evaluated for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and hexachlorobenzene (HCB) in Baltic Sea surface water and sediment. Modeled dissolved concentrations are usually within a factor of 2-4 of observed concentrations, however with larger deviations for furans. Calculated concentrations in particulate organic matter are less accurate (within factors of 1-700), likely due to errors in estimated pelagic biomass, particulate matter-water partitioning, and large natural variability in field data. Concentrations in sediments are usually predicted within a factor of 6. The good performance of the model illustrates its usefulness for exploration of contaminant fate in response to variations in nutrient input and climatic conditions in the Baltic Sea marine environment.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Models, Chemical; Polychlorinated Biphenyls; Seawater; Water Pollutants, Chemical

The World Health Organization recently proposed the inclusion of brominated congeners in addition to chlorinated congeners when computing the toxic equivalency (TEQ) of dioxin-like compounds (DLCs) in assessments of human health risks. In the present study, 12 polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) were analyzed by gas chromatography/high resolution mass spectrometry in the composited, archived biosolids that were collected in 32 U.S. states and the District of Columbia from 94 wastewater treatment plants by the United States Environmental Protection Agency in its 2001 national sewage sludge survey. Two PBDDs and five PBDFs were detected in the biosolids composites at varying frequencies (40-100%) with a total mean concentration of 10,000 ng/kg dry weight (range: 630-42,800), of which 1,2,3,4,6,7,8-hepta-BDF constituted about 95% by mass. Relative to commercial polybrominated diphenyl ether (PBDE) formulations, the ratio of PBDD/Fs to PBDEs in biosolids was 55-times higher (∼ 0.002% vs ∼ 0.11%), which indicates potential PBDE transformation or possibly additional sources of PBDD/Fs in the environment. The TEQ contribution of PBDD/Fs was estimated at 162 ng/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (range: 15-672), which is equivalent to 75% (range: 12-96%) of the total TEQ in biosolids. The TEQ of DLCs released annually to U.S. soils as a result of the land application of biosolids was estimated at 720 g (range: 530-1600 g). Among all known DLCs determined in biosolids, brominated analogs contributed 370% more TEQ than did chlorinated congeners, which indicates the need to include brominated DLCs in the exposure and risk assessment of land-applied biosolids.

Topics: Benzofurans; Data Collection; Dioxins; Halogenated Diphenyl Ethers; Sewage; United States; United States Environmental Protection Agency

Increased electronic waste (e-waste) has raised public concerns regarding exposure to numerous toxic contaminants, particularly polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In China, the body burdens of PCBs, PBDEs and PCDD/Fs are associated with thyroid hormones in populations from e-waste dismantling sites; however, it is unclear whether this association occurs in children. In this study, we determined the serum levels of PCBs, PBDEs and PCDD/Fs and the endocrine hormones including free triiodothyronine (FT3), total triiodothyronine (TT3), free thyroxine (FT4), total thyroxine (TT4), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), cortisol and growth hormone (GH) in 21 children from an e-waste dismantling area and 24 children from a control area. The results showed that the mean levels of ∑PCBs and ∑PBDEs in the exposure group were significantly higher than in the control group (40.56 and 32.09 ng g(-1) lipid vs. 20.69 and 8.43 ng g(-1) lipid, respectively, p<0.01 for each), and the mean level of ∑PCDD/Fs in the exposure group was higher than in the control group, but the difference was not significant (206.17 vs. 160.27 pg g(-1) lipid, p>0.05). For the endocrine hormones, we did not find significant differences between the exposed and control groups, although the mean levels of FT3, TT3, TT4, ACTH, cortisol and GH were higher, whereas the mean levels of FT4 and TSH were lower in the exposed group. The mean level of ∑PBDEs was positively correlated with the mean levels of ∑PCBs (r=0.60, p<0.05) and ∑PCDD/Fs (r=0.61, p<0.05). Furthermore, the mean level of ∑PBDEs was positively correlated with ACTH (r=0.61, p<0.05). In conclusion, our data suggested that exposure to e-waste dismantling environment increased the body burdens of PCBs and PBDEs in local children and that these contaminants released from the e-waste might contribute to abnormal changes in hormone levels.

Topics: Benzofurans; Child; China; Dioxins; Electronic Waste; Endocrine Disruptors; Environmental Exposure; Environmental Pollutants; Female; Halogenated Diphenyl Ethers; Hormones; Humans; Male; Polychlorinated Biphenyls

Assessing the toxicological significance of complex environmental mixtures is challenging due to the large number of unidentified contaminants. Nontargeted analytical techniques may serve to identify bioaccumulative contaminants within complex contaminant mixtures without the use of analytical standards. This study exposed three freshwater organisms (Lumbriculus variegatus, Hexagenia spp., and Pimephales promelas) to a highly contaminated soil collected from a recycling plant fire site. Biota extracts were analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and mass defect filtering to identify bioaccumulative halogenated contaminants. Specific bioaccumulative isomers were identified by comprehensive two-dimensional gas chromatography high-resolution time-of-flight mass spectrometry (GCxGC-HRToF). Targeted analysis of mixed brominated/chlorinated dibenzo-p-dioxins and dibenzofurans (PXDD/PXDFs, X = Br and Cl) was performed by atmospheric pressure gas chromatography tandem mass spectrometry (APGC-MS/MS). Relative sediment and biota instrument responses were used to estimate biota-sediment accumulation factors (BSAFs). Bioaccumulating contaminants varied among species and included polychlorinated naphthalenes (PCNs), polychlorinated dibenzofurans (PCDFs), chlorinated and mixed brominated/chlorinated anthracenes/phenanthrenes, and pyrenes/fluoranthenes (Cl-PAHs and X-PAHs, X = Br and Cl), as well as PXDD/PXDFs. Bioaccumulation potential among isomers also varied. This study demonstrates how complementary high-resolution mass spectrometry techniques identify persistent and bioaccumulative contaminants (and specific isomers) of environmental concern.

Topics: Animals; Aquatic Organisms; Benzofurans; Biota; Cyprinidae; Dibenzofurans, Polychlorinated; Dioxins; Fourier Analysis; Fresh Water; Gas Chromatography-Mass Spectrometry; Halogenation; Oligochaeta; Polycyclic Aromatic Hydrocarbons; Tandem Mass Spectrometry; Water Pollutants, Chemical

Sulfur dioxide (SO2) gas has been reported to be an inhibitor of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation in fly ash. However, other research has suggested little or no inhibitory effect of SO2 gas. Although these studies focused on reactions between SO2 gas and gas-phase chlorine (Cl) species, no attention was paid to thermochemical gas-solid reactions. In this study, we found contrasting effects of SO2 gas depending on the chemical form of copper (CuO vs CuCl2) with a solid-phase inorganic Cl source (KCl). Chlorinated aromatics (PCDD/Fs, polychlorinated biphenyls, and chlorobenzenes) increased and decreased in model fly ash containing CuO + KCl and CuCl2 + KCl, respectively, with increased SO2 injection. According to in situ Cu K-edge and S K-edge X-ray absorption spectroscopy, Cl gas and CuCl2 were generated and then promoted the formation of highly chlorinated aromatics after thermochemical reactions of SO2 gas with the solid-phase CuO + KCl system. In contrast, the decrease in aromatic-Cls in a CuCl2 + KCl system with SO2 gas was caused mainly by the partial sulfation of the Cu. The chemical form of Cu (especially the oxide/chloride ratio) may be a critical factor in controlling the formation of chlorinated aromatics using SO2 gas.

Topics: Benzofurans; Chlorides; Chlorobenzenes; Coal Ash; Copper; Dibenzofurans, Polychlorinated; Dioxins; Hydrocarbons, Chlorinated; Incineration; Models, Chemical; Polychlorinated Biphenyls; Potassium Chloride; Sulfur Dioxide; X-Ray Absorption Spectroscopy

A comprehensive approach was taken to characterize the polyhalogenated dibenzo-p-dioxin and dibenzofuran contents of fire debris. Household and electronics fire simulations were performed to create samples representative of those firefighters most typically come in contact with. Sample analysis was performed using GC×GC-TOFMS to provide a comprehensive profile of the halogenated dioxins and furans present among the two types of fire debris. Both the household fire and electronics fire simulations produced a significant amount of polybrominated dibenzofurans. Only the electronics rich fire simulation produced mixed halogenated (Br/Cl) dibenzofurans in amounts above the limit of detection of the analytical method. Of the mixed halogenated dibenzofurans identified, a majority were those having no commercially available standard to allow for specific congener identification. GC×GC-TOFMS was extremely beneficial for the identification of compound classes due to the manner in which compounds classify in the two-dimensional chromatographic plane, thus aiding data reduction for these materials.

Topics: Air Pollutants; Benzofurans; Dioxins; Electrons; Fires; Gas Chromatography-Mass Spectrometry; Halogenation

The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of all water bodies including transitional waters; its final objective is to achieve at least 'good status' by 2015. In the present work, a hierarchical sampling design was applied to analyze the influence of anthropogenic inputs on the spatial distribution of metals, polychlorinated dibenzo-p-dioxins (PCDDs) dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in sediment at four areas in Pialassa Baiona coastal lagoon. In order to assess the chemical status, levels of priority substances and other pollutants were compared with the recently developed national Environmental Quality Standards (EQS) and site specific background levels for metals. Levels of mercury and PCBs were particularly high and exceeded their national EQS values at all sampled areas, thus not contributing to the achievement of a good chemical status of this transitional water body according to the WFD classification.

Topics: Benzofurans; Dioxins; Environmental Monitoring; Environmental Pollutants; Geologic Sediments; Halogenated Diphenyl Ethers; Italy; Metals, Heavy; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

The bromophenoxy radicals (BPRs) are key intermediate species involved in the formation of polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs). In this work, the formation of BPRs from the complete series reactions of 19 bromophenol (BP) congeners with H and OH radicals were investigated theoretically by using the density functional theory (DFT) method and the direct dynamics method. The geometries and frequencies of the reactants, transition states, and products were calculated at the MPWB1K/6-31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6-311+G(3df,2p) method. The rate constants were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) contribution over a wide temperature range of 600-1200K. The present study indicates that the reactivity of the O-H bonds in BPs as well as the formation potential of BPRs from BPs is strongly related to the bromine substitution pattern. The obtained results can be used for future estimates of PBDD/F emissions quantity based on the well estimated PCDD/F inventory.

Topics: Benzofurans; Bromine; Dioxins; Hydrocarbons, Brominated; Hydrogen; Hydroxyl Radical; Kinetics; Phenols; Temperature

In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme (UNEP) expert consultation took place, during which the possible inclusion of brominated analogues of the dioxin-like compounds in the WHO Toxicity Equivalency Factor (TEF) scheme was evaluated. The expert panel concluded that polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), and some dioxin-like biphenyls (dl-PBBs) may contribute significantly in daily human background exposure to the total dioxin toxic equivalencies (TEQs). These compounds are also commonly found in the aquatic environment. Available data for fish toxicity were evaluated for possible inclusion in the WHO-UNEP TEF scheme (van den Berg et al., 1998). Because of the limited database, it was decided not to derive specific WHO-UNEP TEFs for fish, but for ecotoxicological risk assessment, the use of specific relative effect potencies (REPs) from fish embryo assays is recommended. Based on the limited mammalian REP database for these brominated compounds, it was concluded that sufficient differentiation from the present TEF values of the chlorinated analogues (van den Berg et al., 2006) was not possible. However, the REPs for PBDDs, PBDFs, and non-ortho dl-PBBs in mammals closely follow those of the chlorinated analogues, at least within one order of magnitude. Therefore, the use of similar interim TEF values for brominated and chlorinated congeners for human risk assessment is recommended, pending more detailed information in the future.

Topics: Animals; Benzofurans; Dioxins; Dose-Response Relationship, Drug; Environmental Exposure; Environmental Monitoring; Humans; Polybrominated Biphenyls; Risk Assessment; Soil Pollutants; Toxicity Tests

The quality of sewage sludge-based products, such as composts and growth media, is affected by the contamination of sewage sludge with, potentially, hundreds of different substances. Therefore, it is difficult to achieve the reliable environmental quality assessment of sewage sludge-based products solely based on chemical analysis. In the present work, we demonstrate the use of the kinetic luminescent bacteria test (ISO 21338) to evaluate acute toxicity and the Vitotox™ test to monitor genotoxicity of sewage sludge and composted sewages sludge. In addition, endocrine-disrupting and dioxin-like activity was studied using yeast-cell-based assays. The relative contribution of industrial waste water treated at the Waste Water Treatment Plants led to elevated concentrations of polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) in sewage sludge. The effect of elevated amounts of organic contaminants could also be identified with biotests able to demonstrate higher acute toxicity, genotoxicity, and potential for endocrine-disruptive properties. Additional extraction steps in kinetic luminescent bacteria test with DMSO and hexane increased the level of toxicity detected. Composting in a pilot-scale efficiently reduced the amounts of linear alkylbenzensulphonates (LASs), nonylphenols and nonylphenolethoxylates (NPE/NPs) and PAH with relative removal efficiencies of 84%, 61% and 56%. In addition, decrease in acute toxicity, genotoxicity and endocrorine-disrupting and dioxin-like activity during composting could be detected. However, the biotests did have limitations in accessing the ecotoxicity of test media rich with organic matter, such as sewage sludge and compost, and effects of sample characteristics on biotest organisms must be acknowledged. The compost matrix itself, however, which contained a high amount of nutrients, bark, and peat, reduced the sensitivity of the genotoxicity tests and yeast bioreporter assays.

Topics: Aliivibrio fischeri; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Ecotoxicology; Endocrine Disruptors; Luminescent Measurements; Mutagenicity Tests; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Sewage; Soil; Toxicity Tests; Toxicity Tests, Acute; Water Pollutants, Chemical; Yeasts

This study presents a detailed mechanistic and kinetic investigation that explains the experimentally observed high yields of formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from the polybrominated diphenyl ethers (PBDEs), commonly deployed in brominated flame retardants (BFRs). Theoretical calculations involved the accurate meta hybrid functional of M05-2X. The previously suggested pathways of debromination and generation of bromophenols/bromophenoxys/bromobenzenes were found to be unimportant corridors for the formation of PBDD/Fs. A loss of an ortho Br or H atom from PBDEs, followed by a ring-closure reaction, is the most accessible pathway for the production of PBDFs via modest reaction barriers. The initially formed peroxy-type adduct (RO₂) is found to evolve in a complex, nevertheless very exoergic, mechanism to produce PBDDs. Results indicate that, degree and pattern of bromination, in the vicinity of the ether oxygen bridge, has a minor influence on governing mechanisms and that even fully brominated isomers of BFRs are capable of forming PBDD/Fs. We thoroughly discuss bimolecular reactions of PBDEs with Br and H, as well as the Br-displacement reaction by triplet oxygen. The rate of the Br-displacement reaction significantly exceeds that of the unimolecular inititiation reactions due to loss of ortho Br or H. Results presented herein address conclusively the intriguing question of how PBDEs form PBDD/Fs, a matter that has been in the center of much debate among environmental chemists.

Topics: Benzofurans; Bromine; Dioxins; Halogenated Diphenyl Ethers; Kinetics

Some substances are mixtures of very large number of constituents which vary widely in their properties, and thus also in terms of their environmental fate and the hazard that they may pose to humans and the environment. Examples of such substances include industrial chemicals such as the chlorinated paraffins, technical pesticides such as toxaphene, and unintended combustion side products, such as mixed halogenated dibenzo-p-dioxins and dibenzofurans. Here we describe a simple graphical superposition method that could precede a more detailed hazard assessment for such substances. First, partitioning and degradation properties for each individual constituent of a mixture are estimated with high-throughput quantitative structure-property relationships. Placed in a chemical partitioning space, i.e. a coordinate system defined by two partitioning coefficients, the mixtures appear as 'clouds'. When model-derived hazard assessment metrics, such as the potential for bioaccumulation and long range transport, are superimposed on these clouds, the resulting maps identify the constituents with the highest value for a particular parameter and thus potentially the greatest hazard. The maps also indicate transparently how the potential for long range transport and bioaccumulation is dependent on structural attributes, such as chain length, and the degree and type of halogenation. In contrast to previous approaches, in which the mixture is represented by a single set of properties or those of a few selected constituents, the whole range of environmental fate behaviors displayed by the constituents of a mixture are being considered. The approach is illustrated with three sets of chemical substances.

Topics: Animals; Benzofurans; Complex Mixtures; Dioxins; Environmental Monitoring; Environmental Pollutants; Halogenation; Humans; Models, Biological; Models, Chemical; Paraffin; Toxaphene

Two artificial wastes (A and B) whose contents reflect regional differences in municipal solid waste composition, were used to investigate the thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) during incineration. Flue gas samples were simultaneously collected at three ports in the post-combustion zone corresponding to flue gas temperatures of 400, 300, and 200 °C. The combustion of Waste B, which had a higher chlorine and metal content than Waste A, produced greater levels of highly-chlorinated homologues, as demonstrated by a higher degree of chlorination. The total concentrations of PCDDs, PCDFs, PCBs, and PCNs formed in the combustion of both wastes increased as temperature decreased along the convector. There were no significant differences in total concentrations between Waste A and Waste B combustion at specific temperatures, with exception of PCDFs at 400 °C. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) modeling, used to evaluate the data for all compound groups, suggest that during flue gas quenching at temperatures of 400 °C low-chlorinated homologues are preferentially formed in the presence of copper, which is known to be a very active catalyst for this process. At 300 and 200 °C, the formation of highly-chlorinated homologues is favored.

Topics: Air Pollutants; Benzofurans; Dioxins; Environmental Monitoring; Hot Temperature; Incineration; Naphthalenes; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

This article presents the results of the most recent estimation of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) atmospheric emissions in Portugal, which has covered the period 2004-2009 and includes 27 emission sources types. The results are compared with previous emissions inventories published for Portugal. The main objective of this work is to provide relevant information about the amounts of the compounds that are released into the atmosphere in Portugal, and identify their major sources and trends. The methodology involved the identification of relevant sources, the collection of information to characterize these sources, the selection of appropriate emission factors and their application to estimate the emissions. Furthermore, several studies conducted in Portugal were considered, namely reports from PCDD/PCDF measurements performed in some industrial facilities. The inventory covered 27 emission sources types. However the results show that only 8 were relevant, i.e. with emission amounts greater than 1 g I-TEQ year(-1). The total emissions of PCDD/PCDF in Portugal reached between 40 and 105 g I-TEQ year(-1), for the period of 2004-2009. The largest emission source and at same time with greater variation is forest fires, with emissions between 3 g I-TEQ year(-1) and 67 g I-TEQ year(-1) in 2008 and 2005, respectively. Excluding the emissions from forest fires, the total emission is more or less constant over the years and around 37 g I-TEQ year(-1).

Topics: Air Pollutants; Air Pollution; Atmosphere; Benzofurans; Dioxins; Environmental Monitoring; Industry; Portugal

One hundred and fifty one soil samples from 125 sampling points were collected near E-waste dismantling sites and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs). Total concentration of PCDD/Fs in topsoil samples ranged from 280 pg x g(-1) to 7 010 pg x g(-1) dry weight with the mean value of 1 380 pg x g(-1) dry weight. The mean value of the second layer and the deepest layer is 63% and 38% of that of top soils, respectively. The toxic equivalent quantity (TEQ) of PCDD/Fs in top soils ranged from 1.4 pg x g(-1) to 94.8 pg x g(-1) (I-TEQ). According to the guidelines for TEQ concentrations established in Germany, 19 of 125 topsoil samples (15% of the total topsoil samples analyzed) could not be expected to pose human health hazards. The rest of 85% of top soils needs investigations of source identification. If the contribution of PCB to TEQ was considered, 98% of top soils need investigations of source identification. Principle component analysis (PCA) is used to identify the PCDD/Fs sources. The homologue profiles of PCDD/Fs showed that dismantling activities are the main emission resources of the PCDD/Fs from thermal processes, also are the main emission resources of the PCDD/Fs in soils of this area.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Electronic Waste; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Soil; Soil Pollutants

In 1997, the Polychlorinated dibenzo-para-dioxin (PCDD)/Polychlorinated dibenzofuran (PCDF) concentrations in dairy products in Germany and other European countries increased. The PCDD/PCDF source was contaminated lime used in Brazilian citrus pulp pellets. The contaminated lime was mined from an industrial dump site. However, the detailed origin of the PCDD/PCDFs in the lime was not revealed. This paper investigates the contamination origin and describes the link between lime milk from the dumpsite of a chlorine/organochlorine industry and the contaminated lime. The contaminated lime stem from mining at the corporate landfill of Solvay Indupa in Sao Paulo. The landfill was used for 40 years for deposition of production residues and closed in 1996. The factory operated/operates at least two processes with potentially high PCDD/PCDFs releases namely the oxychlorination process for production of ethylene dichloride (EDC) and the chlor-alkali process. The main landfilled waste was lime milk (1.4 million tons) from the vinyl chloride monomer production (via the acetylene process) along with residues from other processes. The PCDD/PCDF fingerprint revealed that most samples from the chemical landfill showed an EDC PCDD/PCDF pattern with a characteristic octachlorodibenzofuran dominance. The PCDD/PCDF pattern of a Rio Grande sediment samples downstream the facility showed a chlor-alkali pattern with a minor impact of the EDC pattern. The case highlights that PCDD/PCDF- and persistent organic pollutants-contaminated sites need to be identified in a comprehensive manner as required by the Stockholm Convention (article 6) and controlled for their impact on the environment and human health. Landfill mining and reuse of materials from contaminated deposits should be prohibited.

Topics: Animal Feed; Animals; Benzofurans; Brazil; Calcium Compounds; Chemical Industry; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Food Contamination; Germany; Hazardous Waste; Industrial Waste; Milk; Mining; Oxides

A screening of metals, persistent organic pollutants, pharmaceuticals and personal care products (PPCPs), and other organic contaminants in sludge from seven Swedish sewage treatment plants (STPs) was performed in this study. This extensive screening provides information on mass flows of 282 compounds used in the Swedish society to sewage sludge. It reveals constant relative contaminant concentrations (ng mg kg(-1) d.w.), except for some pesticides and perfluorinated compounds, indicating that these originate from broad usage and diffuse dispersion rather than (industrial) point sources. There was a five order of magnitude difference in the sum concentrations of the most and least abundant species (metals and polychlorinated dibenzo-p-dioxins and -furans, respectively). Lower total concentrations were found in sludge from STPs processing primarily food industry or household sewage. Proportions of the amounts used (in Sweden) found in sludge were lower for compounds that are present in consumer goods or are diffusely dispersed into the environment (0.01-1% recovered in sludge) than for compounds used as detergents or PPCPs (17-63%). In some cases, the recovery seemed to be affected by evaporation (e.g. octamethylcyclotetrasiloxane) or biotransformation (e.g. adipates) losses, while polychlorinated alkanes and brominated diphenyl ethers were recovered to disproportionately high degree (ca. 4%); likely due to incomplete statistics for imported goods.

Topics: Benzofurans; Dioxins; Environmental Monitoring; Halogenated Diphenyl Ethers; Household Products; Metals; Pesticides; Sewage; Sweden; Waste Disposal, Fluid; Water Pollutants, Chemical; Water Pollution, Chemical

Concentrations of persistent organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in the liver and adipose tissue of Japanese cadavers were measured, and their toxicokinetics were examined in association with hepatic cytochrome P450 (CYP) 1A protein expression levels. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were 66±74 and 65±57 pg/g lipid weight (mean±S.D.) in the liver and adipose tissue, respectively. Total PCBs (sum of 62 congeners targeted), p,p'-dichlorodiphenyl-dichloroethylene (p,p'-DDE) and β-hexachlorocyclohexane (β-HCH) were detected at concentrations over 1 μg/g lipid in both tissues of some specimens. For most of the dioxin-like congeners, total PCBs, p,p'-DDE, oxychlordane, α- and β-HCH, hexachlorobenzene (HCB), and tris(4-chlorophenyl)methane (TCPMe), age-dependent increases in concentrations were found in the adipose tissue of males. No such age-dependent trend was observed in the liver, suggesting that there are different mechanisms underlying the hepatic concentrations of OCs. Immunoblot analyses indicated detectable expression of hepatic CYP1A2 protein, whereas no CYP1A1 protein was detected. The CYP1A2 expression levels were positively correlated with concentrations (on wet weight basis) of 2,3,4,7,8-P₅CDF, the dominant TEQ-contributed congeners in the liver, indicating the induction of this CYP. Hepatic CYP1A2 protein levels were strongly correlated with the liver to adipose concentration (L/A) ratios of PCDD/F congeners with more than 5 chlorine atoms. Together with higher concentrations of the congeners in the liver than in the adipose tissue, the observation on L/A ratios of highly chlorinated PCDD/Fs suggests that induced hepatic CYP1A2 protein is involved in their sequestration in this human population, as observed in model animals (rodents). Nonetheless, the magnitude of hepatic sequestration (L/A ratio) of PCDD/Fs in this human population was lower than in other mammals and birds, reported previously. This study emphasizes the fact that toxicokinetics of some OCs can be affected at least partly by CYP1A2 protein levels in humans. For the extrapolation of their toxicokinetics from model animals to humans, knowledge on the induction and sequestration potencies of CYP1A is necessary.

Topics: Adipose Tissue; Adult; Aged; Aged, 80 and over; Benzofurans; Chlordan; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP1A2; Cytochrome P-450 Enzyme System; Dibenzofurans, Polychlorinated; Dichlorodiphenyl Dichloroethylene; Dioxins; Environmental Exposure; Environmental Pollutants; Female; Hexachlorobenzene; Hexachlorocyclohexane; Humans; Hydrocarbons, Chlorinated; Japan; Liver; Male; Middle Aged; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

We report on the content of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 15 breast milk samples of nursing women living in the city of Taranto (Southern, Italy) or nearby. Breast milk samples were collected over the 2008-2009 period and analyzed by gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) upon accelerated solvent extraction (ASE) using acetone/n-hexane mixture 1:1 (v/v). The method was validated demonstrating good performing features. Profiles of PCDD/PCDF congeners in breast milk samples exhibited a prevalence of PCDFs compared to PCDDs. Toxic equivalents (TEQs in picogram per gram fat) of four breast milk were far above the legal limit for human consumption of 3.0 pg/g; their estimated daily and weekly dietary intake were almost 5-20 and 10-40 times higher, respectively, than the tolerable intake values established by the World Health Organization.

Topics: Adolescent; Adult; Benzofurans; Dioxins; Environmental Exposure; Female; Gas Chromatography-Mass Spectrometry; Humans; Italy; Milk, Human; Young Adult

Sixty breast milk samples were collected in Shenzhen, China from July to November in 2007. The samples were analyzed of the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The range of upper-bound for ∑TEQ-(PCDD/Fs+PCBs) in the samples was 4.10-35.3 pg TEQ g(-1) lipid (median: 10.6 pg TEQ g(-1) lipid; mean: 11.9 pg TEQ g(-1) lipid). The levels of the measured contaminants in the breast milk had significant correlations with the length of inhabitation period in Shenzhen (r=0.487, p<0.05 for PCDD/Fs, r=0.431, p<0.05 for PCBs and r=0.478, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)), and the consumption rate of fish (r=0.366, p<0.05 for PCDD/Fs, r=0.486, p<0.05 for PCBs and r=0.416, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)), respectively. Moreover, significant positive correlations were also detected between the participant's age (r=0.305, p<0.05 for ∑TEQ-PCBs and r=0.275, p<0.05 for ∑TEQ-(PCDD/Fs+PCBs)) and the body burdens of these contaminants respectively. It is estimated that the daily intake (EDI) of the sum of PCDD/Fs and DL-PCBs by the breast-fed infants was 5.60-161 pg TEQ kg(-1) bw per day (mean: 48.2 pg TEQ kg(-1) bw per day; median: 42.2 pg TEQ kg(-1) bw per day). The result showed that both the body burdens of PCDD/Fs and PCBs of the recruit population and the calculated EDI of the breast-fed infants were higher than those in the non-exposed areas in mainland China. This suggests that continuous surveillance on PCDD/Fs and PCBs levels in human milk is critical to more precisely evaluate the human health risk posed by the negative environmental impact in Shenzhen in the future.

Topics: Adult; Benzofurans; Body Burden; Breast Feeding; China; Dibenzofurans, Polychlorinated; Dioxins; Environmental Exposure; Environmental Pollutants; Environmental Pollution; Female; Humans; Infant; Infant, Newborn; Longitudinal Studies; Milk, Human; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Young Adult

Studies on the association of maternal exposure to polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) with decreased birth weight in humans have produced conflicting results. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease.. The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on birth weight.. Blood samples, obtained from 101 Yusho women (190 births) who gave birth after exposure, were analyzed for congeners of seven PCDDs, ten PCDFs, and four non-ortho PCBs.. Total PCDD TEQ (adjusted beta=-161.9g; 95% CI, -265.3 to -58.6), total PCDF TEQ (adjusted beta=-105.9g; 95% CI, -179.5 to -32.2), and total non-ortho PCBs (adjusted beta=-178.4g; 95% CI, -318.3 to -38.5) levels were inversely associated with birth weight. Significant inverse associations with birth weight were also found for total PCDD TEQ, total PCDF TEQ, and total non-ortho PCB TEQ levels among male, but not female, infants. Significant inverse associations with birth weight were also found for nine congeners among all infants; the adjusted beta coefficients were largest for 1,2,3,6,7,8-HxCDD and smallest for 2,3,4,7,8-PeCDF.. In the setting of exposure to high levels of dioxins, maternal blood levels of PCDDs, PCDFs and PCBs are associated with lower birth weight in Yusho patients. The association exhibited gender-specific differences, as male infants are more susceptible than females to growth restriction induced by in utero dioxin exposures.

Topics: Adult; Benzofurans; Birth Weight; Cohort Studies; Dibenzofurans, Polychlorinated; Dioxins; Female; Food Contamination; Humans; Infant; Japan; Male; Maternal Exposure; Oryza; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Porphyrias; Young Adult

We investigated the occurrence and distribution patterns of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in six sediment samples from the Xiangjiang River, Hunan Province, People's Republic of China. Total concentrations of PCDD/Fs ranged from 876 to 497,759 (mean 160,766) ng/kg dw, the highest of which exceeded that have ever been reported for sediment samples. World Health Organization total toxicity equivalent (WHO-TEQ) concentrations in three out of six samples were significantly higher than the guidance level (21.5 ng WHO-TEQ/kg dw) suggested by Canadian Sediment Quality Guideline. A predominance of octachlorodibenzo-p-dioxin (OCDD) was observed with an average contribution of 90.8% to the total PCDD/F concentrations, while 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) was the major contributor to the PCDD/F WHO-TEQ concentrations in most of the sites. Such high levels of OCDD and HpCDD may be attributed to the presence of PCP/PCP-Na pollution, although MB-WW, agricultural straw open burning, and boilers-hazardous wastes were also the potential sources of PCDD/Fs. This is the first report for the concentrations and congener profiles of PCDD/Fs in sediment samples from the Xiangtan, Zhuzhou, and Changsha sections of the Xiangjiang River, providing scientific evidence for establishing priorities to reduce ecological risks posed by PCDD/Fs in the rapidly developing areas of Hunan Province and elsewhere.

Topics: Benzofurans; China; Dibenzofurans, Polychlorinated; Dioxins; Endocrine Disruptors; Environmental Monitoring; Geologic Sediments; Rivers; Water Pollutants, Chemical; Water Pollution, Chemical

The congener patterns of mono- to octa-chlorinated dibenzo-p-dioxins (PC(1-8)DD), dibenzofurans (PC(1-8)DF), naphthalenes (PC(1-8)N), mono- to deca-chlorinated biphenyls (PC(1-10)B), di- to hexa-chlorinated benzenes (PC(2-6)Bz) and mono- to penta-chlorinated phenols (PC(1-5)Ph) in flue gas samples collected simultaneously at 450°C, 300°C and 200°C in the post-combustion zone during waste incineration in a laboratory-scale reactor in a previous study, were in this study evaluated using principal component analysis (PCA). To our knowledge this is the most comprehensive chemical and multivariate analysis to date of the thermal formation of dioxins. The PCA indicated that different formation pathways occur in the temperature regions 450-300°C and 300-200°C, and reflected a chlorination effect of PCDF and PCDD between 450°C and 200°C which could not be discerned or was less pronounced for the other compound groups. Toxic equivalents (TEQs) of PCDDs, PCDFs and PCBs, as well as total TEQ values (TEQ(Total)) were also calculated, and correlations between changes in levels of specific congeners and the TEQs were explored in the PCA. Levels of four HxCDF congeners and 1,2,3,4,8-, 1,2,3,7,8-PeCDF and 2,3,4,7,8-PeCDF showed the strongest correlations with TEQ(Total) (R(2)≥0.9). In addition, levels of 1,2,4-TriCBz correlated strongly with TEQ(Total) (R(2)>0.7), supporting previous reports that it may be a potential indicator of the TEQ.

Topics: Benzofurans; Dioxins; Incineration; Naphthalenes; Pentachlorophenol; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

This study focuses primarily on the inventory of PCDD/Fs and PBDD/Fs associated with the low-temperature thermal processing of scrap printed circuit boards (PCBs). Twelve 2,3,7,8-substituted PBDD/Fs congeners were found in various sample outputs, with a total content of 60,000 ng TEQ/kg at 250°C under air atmosphere. A rapid increase of PBDD/Fs was produced with 160,000 ng TEQ/kg, at 275°C-about twice that under the N(2) atmosphere. At 275°C, the total contents of PCDD/Fs were only 170 and 770 ng TEQ/kg under an N(2) and air atmospheres respectively. The results reveal that a large contribution of PBDD/Fs emission may be expected from the dismantling or any other thermal processing of PCB scrap. PCDD/Fs, however, are formed and released into the environment in a variety of ways. Additional research is required to look for the causal factors that affect emissions.

Topics: Air Pollutants; Benzofurans; Dioxins; Electronic Waste; Hydrocarbons, Brominated; Incineration

High levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), mono- and non-ortho-polychlorinated biphenyls (PCBs), and polybrominated dibenzo-p-dioxins (PBDDs) are found in fish from coastal areas in the Baltic Sea, which may cause ecotoxicological effects. To increase our understanding of the persistency of the emerging pollutants polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), fish feed was spiked with 21 PBDD/Fs, 17 PCDD/Fs, and 30 PCBs and fed to zebrafish (Danio rerio). Concentrations in fish and eggs were examined during a 6- or 12-week uptake period, and a 6-week elimination period. Steady-state was reached for 2-, 3-, 7-, and/or 8-substituted tri- and tetra-BDD/Fs; 2,3,7,8-tetra-BDD (2,3,7,8-TeBDD) was the most strongly retained. Steady-state was not reached for tetra- to hexa-CDDs. Non-2,3,7,8 congeners showed little or no retention. Most PCBs had high retention and did not reach steady state. Half-lives decreased in the order PCBs > PCDD/Fs > PBDD/Fs. Concentrations of 2,3,7,8-substituted penta- to octa-CDD/Fs decreased with their degree of chlorination, suggesting that the rate-limiting factor for uptake is low bioavailability. Maternal transfer was observed for all retained compounds, with most transfer factors <1, indicating that transfer rates are affected by the poor water solubility of the compounds. The limited retention of the major PBDD congeners found in Baltic Sea fish suggests that they are exposed to high or very high concentrations via either food or water.

Topics: Animals; Benzofurans; Diet; Dioxins; Environmental Exposure; Environmental Monitoring; Female; Oceans and Seas; Ovum; Polychlorinated Biphenyls; Water Pollutants, Chemical; Zebrafish

Concentrations of polychlorinated dibenzofurans (PCDFs) and other dioxin-like compounds in soils and sediments of the Tittabawassee River and associated floodplains downstream of Midland, Michigan, USA, are greater than upstream sites. As a result of these concentrations, which are some of the greatest ever reported, a site-specific exposure assessment of belted kingfisher breeding in the assessment area was conducted. To reduce the uncertainty associated with predicting exposure from abiotic matrices, concentrations of residues were quantified in site-specific prey items and in eggs and nestlings of belted kingfisher. Dietary exposure, expressed as the potential average daily dose, based on site-specific concentrations of PCDFs, polychlorinated dibenzo-p-dioxins (PCDDs), and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ(WHO-Avian)) in prey items was consistently greater along the Tittabawassee River than in associated reference areas and further downstream sites in the Saginaw River. Concentrations of PCDD/DFs in eggs and nestlings of belted kingfisher varied among sampling areas, being greater in both eggs and nestlings nesting along the Tittabawassee River compared to those of belted kingfisher from upstream reference areas. Geometric mean concentrations of PCDD/DFs were 130 and 200 ng/kg wet weight in eggs and nestlings of belted kingfisher, respectively. These concentrations are the equivalent of 84 and 95 ng TEQ(WHO-Avian)/kg. Site-specific biomagnification factors for select PCDD/DF congeners ranged from <1.0 to 1.8 in belted kingfisher.

Topics: Animals; Benzofurans; Birds; Dibenzofurans, Polychlorinated; Diet; Dioxins; Food Chain; Michigan; Ovum; Polychlorinated Dibenzodioxins; Rivers; Soil; Soil Pollutants

Nitrogen containing compounds such as ammonia, urea and amines can effectively inhibit the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Sewage sludge accumulates both sulfur and nitrogen during wastewater treatment so it could be used to reduce PCDD/Fs formation. Indeed, it is observed in this study that the gas evolving from the sludge drying process can significantly suppress chlorobenzene (CBz) and PCDD/Fs formation from fly ash collected from a hospital waste incinerator. For instance, the reduction of hexachlorobenzene (HxCBz) and PCDD/Fs amount was 92.1% and 78.7%, respectively, when the drying gas evolving from 2g sludge flew through 2g fly ash. These tests were conducted in the frame of projects devoted to hospital waste incineration. The disposal technology for hospital waste (HW), developed in this institute, features rotary kiln pyrolysis combined with post-combustion followed by flue gas cleaning. Hence, some preliminary tests were devoted to investigate dioxins suppression by co-pyrolysis and co-combustion of polyvinyl chloride (PVC) and sludge in lab scale. More experimental research will be conducted to appropriately assess these effects of sludge on PCDD/Fs emissions during co-pyrolysis/combustion of HW and sludge.

Topics: Ammonia; Benzofurans; Chemical Phenomena; Chlorobenzenes; Coal Ash; Dibenzofurans, Polychlorinated; Dioxins; Equipment Design; Hexachlorobenzene; Hospitals; Incineration; Medical Waste Disposal; Nitrogen; Polychlorinated Dibenzodioxins; Sewage

Chlorinated pesticides can contain impurities of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and their precursors, as a result of various manufacturing processes and conditions. As precursor formation of PCDD/Fs can also be mediated by ultraviolet light (UV), this study investigated whether PCDD/Fs are formed when currently used pesticides are exposed to natural sunlight. Formulations containing pentachloronitrobenzene (PCNB; n=2) and 2,4-dichlorophenoxyacetic acid (2,4-D; n=1) were exposed to sunlight in quartz tubes, and the concentration of 93 PCDD/F congeners were monitored over time. Considerable formation of PCDD/Fs was observed in both PCNB formulations (by up to 5600%, to a maximum concentration of 57000 μg ∑PCDD/F kg(-1)) as well as the 2,4-D formulation (by 3000%, to 140 μg ∑PCDD/F kg(-1)). TEQ also increased by up to 980%, to a maximum concentration of 28 μg kg(-1) in PCNB, but did not change in the 2,4-D formulation. Assuming similar yields as observed in the present study as a worst case scenario the use of PCNB in Australia may result in the formation of 155 g TEQ annum(-1), contributed primarily by OCDD formation. This warrants detailed evaluations on the contemporary release of PCDD/Fs to the environment after the use of pesticides. Changes in congener profiles (including the ratio of PCDDs to PCDFs (DF ratio)) suggest that pesticide sources of PCDD/Fs after sunlight exposure may not be recognized based on matching source fingerprints established from manufacturing impurities. These changes also provide preliminary insights into the possible formation routes and types of precursors involved.

Topics: Benzofurans; Dioxins; Nitrobenzenes; Pesticides; Photolysis; Sunlight

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in surface sediment samples from Taihu Lake--an important water supply of the Yangtze River Delta, China--were investigated in the present study. Concentrations of PCDD/Fs ranged from 0.91 to 4.8 pg TEQ g(-1) dw (mean: 2.9 pg TEQ g(-1) dw, TEQ: Toxic Equivalent), which were all higher than the threshold effect level established by interim sediment quality guidelines in Canada (0.85 pg TEQ g(-1) dw). The levels of PBDD/Fs ranged from 0.16 to 1.6 pg TEQ g(-1) dw (mean: 0.52 pg TEQ g(-1) dw) and accounted for 5-33% (mean: 14%) of the total PCDD/Fs and PBDD/Fs TEQ. Comparatively, the abundance of sedimentary PCDD/Fs in the three regions (Meiliang Bay, Gonghu Bay, and Xukou Bay) showed a decreasing trend from the inflow region to the outflow region, while no significant difference was observed among their 2,3,7,8-PBDD/Fs levels, which suggested that the sources of PCDD/Fs and PBDD/Fs differed in this area. Principal component analysis suggested that the historical production/usage of pentachlorophenol and sodium pentachlorophenate was the dominant source of PCDD/Fs in the sediment of these regions. Although the specific sources of PBDD/Fs in the sediment of Taihu Lake were unclear, it was suspected to be due to atmospheric deposition; however, an additional study is needed to confirm this.

Topics: Benzofurans; Bromine Compounds; China; Chlorine Compounds; Dioxins; Environmental Monitoring; Geologic Sediments; Lakes; Water Pollutants, Chemical; Water Pollution, Chemical

The concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs) were measured in two sediment cores collected from Jiaozhou Bay. The concentrations of PCDD/Fs, dioxin-like PCBs, and PCNs in the cores were in the range of 2.8-26.3, 7.1-82.4 and 3.9-56.4 pg/g dw, respectively. The depth profiles of total concentrations PCDD/Fs and dioxin-like PCBs were similar in the sediment core J37 inside Jiaozhou Bay, but different from those in the sediment core J94 outside the bay, suggesting the different sources. In both cores Tri-CNs and Tetra-CNs were dominant, similar to the PCNs composition of some Halowax technical products. The maximal PCNs contamination occurred in the mid-1970s (outside the Bay) and early-1990s (inside the Bay). An increase of the indicator CN congeners characteristic for thermal source in the top layers of the sediment core inside the bay indicated that the contribution from the municipal solid waste incineration has been more important in recent years.

Topics: Benzofurans; China; Dioxins; Environmental Monitoring; Geologic Sediments; Incineration; Naphthalenes; Polychlorinated Biphenyls; Water Pollutants, Chemical

The concentrations of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were determined in a number of foodstuffs purchased in various locations near a hazardous waste incinerator (HWI) in Tarragona County (Catalonia, Spain). The dietary intake of PCDD/Fs by the population of the area under potential influence of the HWI was subsequently estimated. The results were compared with previous surveys performed in the same area in 1998 (baseline), 2002 and 2006. In the present study, the highest WHO-TEQ corresponded to industrial bakery (0.183 ng/kg wet weight, ww), followed by fish (0.156 ng/kg ww), oils and fats (0.112 ng/kg fat weight), and seafood (0.065 ng/kg ww). In contrast, the lowest values were observed in pulses and tubers (0.003 ng/kg ww), and cereals and fruits (0.004 ng/kg ww). The dietary intake of PCDD/Fs by the general population was 33.1pg WHO-TEQ/day, having fish and seafood (11.6 pg WHO-TEQ), oils and fats (4.61pg WHO-TEQ), dairy products (3.79 pg WHO-TEQ), and industrial bakery (3.49 pg WHO-TEQ) as the groups showing the highest contribution to the total TEQ. The lowest daily contributions corresponded to pulses (0.08 pg WHO-TEQ) and tubers (0.25 pg WHO-TEQ). This intake was considerably lower than that found in the baseline study, 210.1 pgI-TEQ/day, and also notably lower than that found in the 2002 survey (59.6 pgI-TEQ/day), but slightly higher than the intake estimated in the 2006 survey, 27.8 pgWHO-TEQ/day. The results of this study show that any increase potentially found in the biological monitoring of the general population living in the area under evaluation should not be attributed to dietary exposure to PCDD/Fs.

Topics: Adolescent; Adult; Benzofurans; Child; Child, Preschool; Diet; Dioxins; Environmental Exposure; Environmental Pollutants; Environmental Pollution; Female; Food Contamination; Hazardous Waste; Humans; Incineration; Male; Middle Aged; Spain; Young Adult

Dioxins and PCBs accumulate in the food chain and might exert toxic effects in animals and humans. In large epidemiologic studies, exposure estimates of these compounds based on analyses of biological material might not be available or affordable.. To develop and then validate models for predicting concentrations of dioxins and PCBs in blood using a comprehensive food frequency questionnaire and blood concentrations.. Prediction models were built on data from one study (n=195), and validated in an independent study group (n=66). We used linear regression to develop predictive models for dioxins and PCBs, both sums of congeners and 33 single congeners (7 and 10 polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), 12 dioxin-like polychlorinated biphenyls (PCBs: 4 non-ortho and 8 mono-ortho), sum of all the 29 dioxin-like compounds (total TEQ) and sum of 4 non dioxin-like PCBs (∑ CB-101, 138, 153, 183=PCB(4)). We used the blood concentration and dietary intake of each of the above as dependent and independent variables, while sex, parity, age, place of living, smoking status, energy intake and education were covariates. We validated the models in a new study population comparing the predicted blood concentrations with the measured blood concentrations using correlation coefficients and Weighted Kappa (К(W)) as measures of agreement, considering К(W)>0.40 as successful prediction.. The models explained 78% (sum dioxin-like compounds), 76% (PCDDs), 76% (PCDFs), 74% (no-PCBs), 69% (mo-PCBs), 68% (PCB(4)) and 63% (CB-153) of the variance. In addition to dietary intake, age and sex were the most important covariates. The predicted blood concentrations were highly correlated with the measured values, with r=0.75 for dl-compounds 0.70 for PCB(4), (p<0.001) and 0.66 (p<0.001) for CB-153. К(W) was 0.68 for sum dl-compounds 0.65 for both PCB(4) and CB-153. Out of 33 congeners 16 (13dl-compounds and 3 ndl PCBs) had К(W)>0.40.. The models developed had high power to predict blood levels of dioxins and PCBs and to correctly rank subjects according to high or low exposure based on dietary intake and demographic information. These models underline the value of dietary intake data for use in investigations of associations between dioxin and PCB exposure and health outcomes in large epidemiological studies with limited biomaterial for chemical analysis.

Topics: Adult; Aged; Aged, 80 and over; Animals; Benzofurans; Diet; Dioxins; Environmental Exposure; Female; Food Contamination; Humans; Male; Middle Aged; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Young Adult

Atmospheric concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) were measured in Taizhou, a large electronic equipment waste (e-waste) recycling area in East China. The mean concentrations (in summer and winter) of PCDD/Fs (0.45 and 0.39 pg WHO-TEQ m⁻³, where WHO-TEQ is the toxic equivalent set by the World Health Organisation), PBDD/Fs (0.22 and 0.18 pg WHO-TEQ m⁻³), and PBDEs (270 and 225 pg m⁻³) in this region have declined compared with those in 2005, due to regulations on primitive e-waste recycling activities. However, these concentrations remain higher than the historically highest levels in Europe and North America. The congener profiles of 2,3,7,8-substituted PCDD/Fs were similar, with OCDD, 1,2,3,4,6,7,8-HpCDF, OCDF, and 1,2,3,4,6,7,8-HpCDD being the most abundant congeners at all sites. The PCDD/F homologue profiles in the present study were different from those typically observed at non-e-waste locations, indicating a distinct source in this region. Seasonal differences were found in the lower brominated PBDE profiles. These differences indicate that the PBDE emission sources in summer (e.g., strong evaporation sources) differed from those in winter. However, the relatively steady congener profiles of the highly brominated PBDEs suggest that these PBDEs were controlled primarily by similar emission mechanisms. The lifetime excess cancer risks from exposure to PCDD/Fs and PBDD/Fs via inhalation ranged from 0.7 × 10⁻⁵ to 5.4 × 10⁻⁵, or approximately 80 cancer cases in the Taizhou population.

Topics: Air Pollutants; Air Pollution; Benzofurans; Bromine Compounds; China; Dioxins; Electronic Waste; Environmental Exposure; Environmental Monitoring; Halogenated Diphenyl Ethers; Humans; Neoplasms; Polychlorinated Dibenzodioxins; Polymers; Risk Assessment

We report measured concentrations of organohalogens and trace elements in muscle and eggs of returning wild Pacific sockeye and chinook salmon during their 2007 migration through the Fraser River watershed in Canada. Chemical analyses revealed the presence of ppb to ppm levels of a wide variety of contaminants in these fish, including polychlorinated biphenyls (PCBs); polychlorinated dibenzo-p-dioxins (PCDDs); polychlorinated dibenzofurans (PCDFs); polybrominated diphenyl ethers (PBDEs); organochlorine pesticides (OCPs) such as DDTs, hexachlorocyclohexanes (HCHs), octachlorostyrene, and cyclodienes; and Hg, As, Cd, Pb, and several other trace elements. Body weights and flesh lipid contents declined during upstream migration, resulting in significantly higher (p < 0.05) lipid-normalized concentrations of lipophilic organohalogens (PCBs, PCDD/Fs, pesticides) in those spawning salmon. Postmigration magnification factors (MFs) of organohalogens (0.1-10) were comparable to previous observations and model predictions. MFs generally increased with increasing hydrophobicity (K(OW)). For example, MFs of tetra- and pentachlorobenzenes and HCH isomers (log K(OW) range: 3.8-5) were relatively low (between 0.1 and 1.7) compared with those of more lipophilic compounds (log K(OW) > 6) such as PCBs, DDTs, and mirex (MFs between 5 and 10). Lipid-normalized muscle:egg ratios in female salmon, which varied between 0.1 and 8, also exhibited a positive relationship with chemical K(OW). The results indicate that lipophilic compounds (K(OW) > 10(6)) can be magnified in flesh lipids of Pacific salmon during spawning migration, but maternal transfer kinetics (deposition to eggs) of those chemicals are relatively slow compared with less hydrophobic compounds. 2,3,7,8-TCDD toxic equivalents (ΣTEQs) in eggs of these spawning salmon, calculated using WHO toxic equivalency factors (WHO-TEFs) for fish health, in some cases exceeded the 0.3 pg·g(-1) threshold level associated with 30% salmonid egg mortality, indicating the potential for reproductive impacts in Fraser River salmon populations.

Topics: Animals; Benzofurans; British Columbia; Dibenzofurans, Polychlorinated; Dioxins; Female; Halogenated Diphenyl Ethers; Lipid Metabolism; Male; Muscles; Ovum; Pesticides; Polychlorinated Biphenyls; Rivers; Salmon; Trace Elements; Water Pollutants, Chemical

In the present work, air-conditioner filter dust samples collected from commercial office, secondary school, shopping mall, electronic factory and manufacturing plant in Hong Kong were collected for 7-ethoxyresorufin O-deethylase (EROD) assay using a hepatoma cell line (H4IIE) and chemical analysis of dioxins including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and PCBs with dioxin-like structure. The result of EROD assay showed that bioassay derived TEQ of 2,3,7,8-TCDD (TEQ(bio)) of dust samples varied from 320 to 730 pg/g. Chemical analyses revealed that chemical derived TEQ of 2,3,7,8-TCDD (TEQ(cal)) of dust samples ranged from 134 to 531 pg/g. In addition, the TEQ(cal) of samples were significantly correlated with TEQ(bio) of samples (R=0.83, P<0.01). The average daily doses (ADDs) of dioxins via indoor dust with the estimated ADDs of dioxins via air and food were compared. The results showed that indoor dust is an important medium of exposure to dioxins.

Topics: Air Pollutants, Occupational; Air Pollution, Indoor; Animals; Benzofurans; Biological Assay; Cell Line, Tumor; Cytochrome P-450 CYP1A1; Dioxins; Dust; Environmental Monitoring; Hong Kong; Humans; Occupational Exposure; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Rats; Risk Assessment; Workplace

This study investigated the homogeneous gas-phase formation of polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs) from 2-BP, 2,4-DBP, and 2,4,6-TBP as precursors. First, density functional theory (DFT) calculations were carried out for the formation mechanism. The geometries and frequencies of the stationary points were calculated at the MPWB1K/6-31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6-311+G(3df,2p) method. Then, the formation mechanism of PBDD/Fs was compared and contrasted with the PCDD/F formation mechanism from 2-CP, 2,4-DCP, and 2,4,6-TCP as precursors. Finally, the rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600-1200 K. Present results indicate that only BPs with bromine at the ortho position are capable of forming PBDDs. The study, together with works already published from our group, clearly shows an increased propensity for the dioxin formations from BPs over the analogous CPs. Multibromine substitutions suppress the PBDD/F formations.

Topics: Air Pollutants; Benzofurans; Bromine Compounds; Dioxins; Kinetics; Phenols

The secondary formation of dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) in the flue gas and ash from the municipal solid waste incinerator (MSWI) systems has attracted considerable public concern. The objective of our research was thus to examine reactions in fly ash from an MSWI operated with different precursors with similar chemical compositions, such as dibenzofurans (DFs), and metal chlorides, such as copper chloride (CuCl(2)). We observed that the concentrations of PCDD/Fs in CuCl(2) and in a mixture of CuCl(2) and DFs were 369.5 and 5307.8 ng/g, respectively, and thus significantly higher in the latter. Due to the catalytic effect of copper ions and the similar structure of dibenzofurans for PCDFs, the effect of the additive in forming PCDD/Fs were obvious. The concentrations of PCDD/Fs in CuCl(2) and copper oxide (CuO) were 369.5 and 97.05 ng/g, respectively. The results also show that the PCDD/Fs concentration when copper chloride was added was four times higher than when copper oxide was added. In addition, the level of activity of the chlorine atoms is greater than that of the oxygen atoms during the formation of PCDD/Fs. This study suggests that the use of metal-containing substances (such as Cu, Cl, Zn) or chlorination precursors (such as DF, chlorobenzene) should be avoided in the combustion process.

Topics: Air Pollution; Benzofurans; Carbon; Coal Ash; Copper; Dioxins; Incineration; Oxides; Particulate Matter; Refuse Disposal

The atmospheric deposition of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) was investigated at four locations in different suburban and urban functional districts of Guangzhou City. The annual deposition fluxes of total PBDD/Fs (eight 2,3,7,8-substituted tetra- to hexa-BDD/Fs) were in the range of 36-51 (mean 46) pg m(-2) day(-1), and the corresponding TEQ fluxes were estimated to range between 7.9 and 11.3 (mean 10.3) pg I-TEQ m(-2) day(-1), indicating a noticeable pollution level. The deposition fluxes of PBDD/Fs during the wet season were 2-4 times as high as those during the dry season. Both rainfall and temperature positively correlated with PBDD/F deposition fluxes. Ambient gas/particle partition coefficients (K(p)) were predicted with SPARC. It appears seasonal variations of PBDD/F deposition fluxes were influenced by meteorological parameters and the local usage of brominated flame retardants (BFRs). The congener profiles of PBDD/Fs at four locations were similar either spatially or temporally, indicating that the main PBDD/F emission sources were similar to one another. Seasonal variations and congener patterns of PBDD/Fs indicated the possible sources included electronic waste recycling, industrial waste incinerators and products containing BFRs.

Topics: Air Pollutants; Air Pollution; Atmosphere; Benzofurans; China; Dioxins; Environmental Monitoring; Seasons

The aim of this study was estimation of PCDD/PCDFs emissions from various sources in Iran. The results indicated total PCDD/PCDFs emissions in Iran in 2010, was 1,957 g TEQ. Of this amount, about 705.8, 0.5, 463.5, 144.1 and 643.2 g TEQ/year was released to air, water, land, products, and in residues, respectively. Open burning processes and metal production are the major contributors to be known environmental sources of PCDD/PCDFs that contribute to about 70% of total PCDD/PCDFs emissions in Iran. The results showed that total PCDD/PCDFs emissions in Iran per inhabitant were about 26.5 g TEQ/million that is high relatively.

Topics: Benzofurans; Dioxins; Environmental Monitoring; Environmental Pollutants; Incineration; Iran; Polychlorinated Dibenzodioxins

Polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) binding with the aryl hydrocarbon receptor (AhR) have been correlated with many toxic responses. Hence, it is very necessary to study the interactions between these ligands and AhR for further understanding of the mechanism of toxicity. In this study, an integrated molecular docking and 3D-QSAR approach was employed to investigate the binding interactions between PCBs, PCDDs, PCDFs and AhR. From molecular docking, hydrogen-bonding and hydrophobic interactions were observed to be characteristic interactions between compounds and AhR. Based on the mechanism of interactions, an optimum 3D-QSAR model with good robustness (Q(CUM)(2)=0.907) and predictability (Q(EXT)(2)=0.863) was developed by partial least squares. Additionally, the developed QSAR model indicated that the molecular size, shape profiles, polarizability and electropological states of compounds were related to the binding affinities to AhR.

Topics: Benzofurans; Dioxins; Hydrogen Bonding; Hydrophobic and Hydrophilic Interactions; Models, Molecular; Polychlorinated Biphenyls; Quantitative Structure-Activity Relationship; Receptors, Aryl Hydrocarbon

Concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in sediments from Bohai Sea and Yellow Sea coastal waters and lakes in Shandong Peninsula were determined. The total PCB concentrations of the measured 50 congeners (Sigma50PCBs) in the sediments ranged from 273.7 to 644.5 pg g(-1) dw (dry weight). The PCB congener profiles in the lacustrine sediments were different from those in the marine sediments. TriCBs and TetraCBs were the dominant homologues in marine sediments, whereas in the sediments from the Nansi Lakes, contributions of PCB homologues were similar. The total concentrations of 2,3,7,8-PCDD/Fs ranged from 6.2 to 27.4 pg g(-1) dw. The congener profiles of 2,3,7,8-substituted PCDD/Fs for the sediments were generally similar for both the lakes and the coastal sea areas in Shandong Peninsula. They were characterized by high OCDD, followed by 1,2,3,4,6,7,8-HpCDD and OCDF. The congener profiles of PCDD/Fs in the sediments were consistent with the profiles of main dominant PCDD/Fs in pentachlorophenol and sodium pentachlorophenate products in China. PCDD/F-TEQ ranged from 0.11 to 0.80 pg TEQg(-1) dw. The dioxin-like PCB-TEQ had concentrations ranging from 0.03 to 0.08 pg TEQ g(-1) dw, mainly from PCB126. PCBs and PCDD/Fs concentrations found in the sediments were from background to low polluted levels.

Topics: Benzofurans; China; Dioxins; Environmental Pollutants; Geologic Sediments; Oceans and Seas; Polychlorinated Biphenyls; Water Pollutants, Chemical

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in agricultural soil samples from Shanghai to determine levels and to identify possible dioxin sources. The dioxin level was measured by an enzyme immunoassay method, US EPA 4025 (modified), which provides results as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents. The Method 4025m results obtained from 60 soil samples displayed a normal distribution, ranging from 2.8 to 23.4 pg/g 2378-TCDD-equvalents, with an average of 11.0 pg/g. The result also revealed a similar PCDD/Fs concentration among crop usage patterns, but differences by geographic region, low in the southwest of Shanghai and considerably higher in the northwest region. In contrast, the dioxin concentrations on Chongming Island were fairly homogeneous, with a range 10-15 pg/g. This immunoassay method is an effective high throughput screening tool which helps to minimize the need for more expensive analyses.

Topics: Agriculture; Benzofurans; China; Crops, Agricultural; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Pilot Projects; Soil; Soil Pollutants

This study investigated the characteristics of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in the stack flue gases of the metallurgical processes. An examination of the PBDEs existing in the stack flue gases of sinter plants revealed that PBDEs can form during the combustion processes through the similar formation conditions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The PBDD/F and PBDE emission rates of the metallurgical facilities were 0.446-3.19 microg TEQ/h and 4470-27000 microg/h, correspondingly. Both emission rates could reach several orders higher than those of the reported sources, revealing that the metallurgical facilities are not only important PCDD/F but also significant PBDD/F and PBDE emission sources to the environment. BDE-209 is the most abundant PBDE congener in the emissions of metallurgical facilities and is found to be dominant in the atmosphere and soils. However, few studies have considered metallurgical facilities as potential PBDE contributors to the environment. Because PBDEs could form or not be completely destroyed in the feeding materials in the combustion system, PBDE contributions from combustion emission sources to the atmosphere should not be ignored and need further investigation.

Topics: Benzofurans; Dioxins; Environmental Monitoring; Environmental Pollutants; Halogenated Diphenyl Ethers; Industrial Waste; Metallurgy

Limited information is available on the applicability of polychlorinated dibenzo-p-dioxin/furan (PCDD/F) toxicity assays to their brominated counterparts: polybrominated dibenzo-p-dioxins/furans (PBDDs/Fs). We estimated the toxicity of mixtures of chlorinated, brominated, and mixed bromochloro-dioxins and -furan (PBCDDs/Fs) laboratory standards using a chemically-activated luciferase gene expression cell bioassay (CALUX). The relative effects potency (REP) values obtained were comparable to the World Health Organization (WHO) toxic equivalency factors (TEFs) and in agreement with the concept of additive congener toxicity of mixtures of dioxins and furans. Enzyme immunoassay (EIA)-based toxic equivalents (TEQs), however, showed overestimation for PCDDs/Fs (0-4 orders of magnitudes higher) and underestimation for PBDDs/Fs (0-1 orders of magnitude lower) when compared to high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS)-based TEQ calculation (using WHO TEFs) in samples from an industrial source line. No correlation was found between the EIA and the HRGC/HRMS data, which could be attributed to differences in homologue-specific cross-reactivity responses, sample matrix type, and presence of other compounds competing for antibody binding in the immunoassay.

Topics: Benzofurans; Biological Assay; Chromatography, Gas; Dioxins; Environmental Pollutants; Enzyme-Linked Immunosorbent Assay; Hydrocarbons, Brominated; Hydrocarbons, Chlorinated; Industrial Waste; Mass Spectrometry; Statistics as Topic

The present study assesses effects of dioxins and related compounds (DRCs) including polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls (DL-PCBs) on cytochrome P450 1A (CYP1A) expression level in liver of black-footed albatrosses (Phoebastria nigripes) collected from the North Pacific. Total 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-T(4)CDD) toxic equivalents (TEQs) derived from toxic equivalency factor for birds proposed by World Health Organization were in the range of 2100 to 10 000 pg/g lipid wt (120-570 pg/g wet wt). Simultaneously, microsomal alkoxyresorufin O-dealkylase (AROD) activities, including methoxy-, ethoxy-, pentoxy-, and benzyloxy-resorufin O-dealkylase activities were also measured in the same specimens. Total TEQs and TEQ (on wet wt basis) from some individual DRC congeners had significant positive correlations with AROD activities, suggesting induction of CYP1A by DRCs. Congeners like 2,3,7,8-T(4)CDD and most of the DL-PCBs that showed no significant positive correlations between the concentrations and AROD activities, exhibited significant negative correlations between AROD activities and the concentration ratio of the congener to a recalcitrant CB169, suggesting preferential metabolism of these congeners by induced CYP1A. As far as we know, this is the first direct evidence revealing that hepatic CYP1A level is elevated with the accumulation of DRCs in the wild black-footed albatross population. The present study gives more robust estimate of impacts of DRCs on CYP1A induction in this rare pelagic species than indexes like hazard quotient and TEQ-threshold comparison that have been so far carried out.

Topics: Animals; Benzofurans; Birds; Chlorine; Cytochrome P-450 CYP1A1; Dioxins; Environmental Pollutants; Liver; Microsomes, Liver; Risk Assessment; Water Pollutants, Chemical

This study was set out to investigate emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from both the stack (i.e., point source) and plant fugitives (i.e., area source) of an electric-arc furnace-dust treatment plant (EAFDTP) and their impact to the vicinity environments. The emission rate of the point source (2,360 ng I-TEQh(-1)) was determined directly by measuring PCDD/F concentrations of the stack flue gas. The emission rate of the area source (1,080 ng I-TEQ m(-2)h(-1)) was estimated by using the Industrial Sources Complex Short-Term (ISCST3) model based on concentrations measured at the downwind side of the plant. The mean emission factors of 785 and 893 ng I-TEQ ton(-1) ZnO were found for the point and area source, respectively. The above results suggest that the area source accounted for more than 50% of total PCDD/F emissions for the selected EAFDTP. The contribution of the point source to the atmospheric PCDD/F concentrations of the upwind site and downwind site of the EAFDTP were 0 and 0.27 fg I-TEQ Nm(-3), respectively. The contributions of the area source were 0.020 and 3.3 fg I-TEQ Nm(-3), respectively. The total contribution of the selected EAFDTP (including both the point and area sources) to the concentrations in both upwind and downwind side vicinities were all less than 10%. Finally, the impact of PCDD/F emissions from the selected EAFDTP to the vicinity atmospheric environments was discussed in the present study.

Topics: Air Pollutants; Benzofurans; Dioxins; Dust; Environmental Monitoring; Incineration

Congeners are molecules based on the same carbon skeleton but different by the number of substituents and/or a substitution pattern. Various Persistent Organic Pollutants (POPs) exist in the environment as families of halogen substituted congeners and/or their hydroxyl and methoxy substituted derivatives. Numbers of possible congeners resulting from substitution of a parent POP molecule with only one type of chemical group are generally available. At the same time, numbers of mixed-substituent congeners have not been counted and presented yet, although there is an increasing interest in such as is the increasing number of research articles presenting results on already identified Cl-/Br-mixed type congeners and/or their HO-/CH(3)O-mixed metabolites. We have enumerated and counted possible mixed-substituent congeners of common POPs. This article presents the obtained numbers for congener families of benzene, naphthalene, biphenyl, diphenyl ether, dibenzo-p-dioxin, dibenzofuran, anthracene, pyrene and others and obtained by substitution of up to five chemical group types.

Topics: Anthracenes; Benzene; Benzofurans; Carbon; Dioxins; Environmental Monitoring; Environmental Pollutants; Molecular Structure; Naphthalenes; Organic Chemicals; Phenyl Ethers; Pyrenes

Here we show that combustion sources, including waste incinerators, metallurgical processes, power-heating systems and so on, are also important emitters of polybrominated diphenyl ethers (PBDEs) to the atmosphere. Geometric mean PBDE concentrations in the stack flue gases of the combustion sources ranged from 8.07 to 469 ng/Nm3. The sinter plants (24.7 mg/h), electric arc furnaces (EAFs) (11.3 mg/h) and power plants (50.8 mg/h) possessed the largest PBDE emission rates, which were several orders higher than those of the other reported sources. The occurrences of the PBDEs in the flue gases of the power plants and vehicles, as well as their PBDE concentrations statistically highly correlated with combustion-originated PCDD/Fs, revealing that PBDEs should be the products of combustion. The ranking of major PBDE emission sources in Taiwanese PBDE inventory for combustion sources was power plants (30.85 kg/year), vehicles (14.9 kg/year) and metallurgical processes (5.88 kg/year).

Topics: Air Pollutants; Air Pollution; Atmosphere; Benzofurans; Dioxins; Environmental Monitoring; Halogenated Diphenyl Ethers; Statistics as Topic

Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from an industrial park operated as Taiwan's center of metallurgical industries were investigated. The characteristics of mean PCDD/F I-TEQ concentrations, congener profiles and emission factors of each source were studied over samples of stack flue gases of individual sources. Different characteristics of congener profiles and large variations of emission factors of secondary aluminum smelters (ALSs) were observed. The mean emission factors of electric arc furnaces were comparable to those for ALSs and much greater than those of municipal solid waste incinerators and sinter plants, but still less than that of clinical waste incinerators. Annual PCDD/F emission contribution of each source was estimated, raising critical concerns over the overall PCDD/F emissions from metallurgical processes. The metallurgical industries altogether contributed approximately 98.1% of the total annual emissions, while waste incinerators only 1.9%. The contributions by sinter plants and metallurgical industries to the total annual emissions of the Park were much higher than the corresponding national averages of Taiwan. The combined dioxin emissions from the entire metallurgical processes and their controls should be seriously envisaged by industrial parks devoted to metal productions.

Topics: Air Pollutants; Aluminum; Benzofurans; Dioxins; Environmental Monitoring; Incineration; Industrial Waste; Industry; Metallurgy; Metals; Models, Statistical; Taiwan

Since 2002, the chemical/petrochemical industrial zone of Tarragona County (Catalonia, Spain) is being annually monitored. As part of the environmental surveillance program, in this study the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), polycyclic aromatic hydrocarbons (PAHs), and metals (As, Cd, Cr, Hg, Mn, Pb and V) were determined in soil and vegetation samples collected in 4 areas of Tarragona County (chemical, petrochemical, urban/residential, and unpolluted). Moreover, the airborne concentrations of the same micropollutants were determined in each area. In soil samples, significant higher levels of PCNs and higher concentrations of PCDD/Fs and PAHs were found in the urban zone. PCDD/F levels in vegetation samples significantly decreased from 2002. The concentrations of Cr in soil samples, as well as V levels in vegetation samples collected in the vicinity of an oil refinery were significantly higher than those found in the unpolluted zones. A significant and progressive increase in V concentrations was also noted. The current results clearly indicate that the petrochemical industry is still being an important focus of inorganic pollution for the surrounding environment. In air, the higher amount of the 7 carcinogenic PAHs suggests a relatively greater impact on the petrochemical and urban areas. The temporal trend of the global pollution was also studied an Integral Risk Index was applied.

Topics: Air; Benzofurans; Dioxins; Environmental Monitoring; Environmental Pollutants; Metals; Naphthalenes; Plants; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Soil; Soil Pollutants; Spain; Time Factors

This study was intended to determine the background levels of PCDD/PCDFs and PCBs in the Taiwanese population and to investigate factors potentially related to PCDD/PCDF and PCB levels. The levels of seventeen PCDD/PCDFs in the 251 serum samples collected from the general population in Taiwan ranged from 4.92 to 26.7 pg WHO(1998)-TEQ/g lipid (median: 11.5) and those of the twelve dioxin-like PCBs ranged between 1.74 and 21.6 pg WHO(1998)-TEQ/g lipid (median: 6.14). Five factors, age, gender, region of residence, dietary status, and smoking status, showed statistically significant association with the TEQ level of PCDD/PCDFs. The TEQ level of PCBs was statistically associated with age only, but not with the other four factors. The trends observed between age and the levels of PCDD/PCDFs and PCBs were not parallel in young subjects (<30 years old) and old subjects (>30 years old). The levels of PCDD/PCDFs and PCBs increased by 0.16 and 0.03 WHO(1998)-TEQ/g lipid per year for subjects above the age of 30, but there was no evidence of any association between age and the levels for subjects below the age of 30 years. These factors should be considered when investigating relationships between background serum levels of persistent organic pollutants and parameters associated with exposure sources or health outcomes.

Topics: Adolescent; Adult; Age Factors; Benzofurans; Biphenyl Compounds; Blood Chemical Analysis; Dioxins; Female; Humans; Male; Middle Aged; Risk Factors; Taiwan; Young Adult

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) levels in a total of 25 food items in Taiwan were surveyed. It was observed that shellfish and saltwater fish possessed the highest PCDD/Fs levels, 9.82 and 3.60 pg WHO-TEQ/g, respectively, on the lipid basis. The dietary intakes of humans at the ages of 12-18, 19-64, and over 65 were determined. The estimated intake were between 21.8 pg (female teenagers) and 37.6 pg (male seniors) WHO-TEQ/day; the levels varied with the dietary habits. The PCDD/F intakes for all human groups are far below the tolerable limit of 70 pg WHO-TEQ/kg b.w./month. In addition, the daily PCDD/F intake levels for duck-farmers consuming average and large amounts of PCDD/F contaminated duck eggs were examined. The result shows that consuming more than one duck egg with level higher than 10 pg WHO-TEQ/g lipid of PCDD/Fs per day could lead to a PCDD/F intake level higher than the tolerable limit. However, for normal population, there is a little risk to ingest intolerable amount of PCDD/Fs because of consuming contaminated duck eggs.

Topics: Adolescent; Adult; Animals; Benzofurans; Child; Dibenzofurans, Polychlorinated; Dioxins; Ducks; Eggs; Female; Fishes; Food Contamination; Humans; Male; Middle Aged; Shellfish; Taiwan; Young Adult

In this study we investigated occurrences and distribution patterns of dioxin-related compounds (DRCs) such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs), polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), monobromo-polychlorinated dibenzo-p-dioxins/dibenzofurans (MoBPCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in marine surface sediments collected from the coastal waters of Hong Kong and Korea. In most sampling sites, concentrations of PCDDs were the highest, followed by DL-PCBs, PCDFs, PBDFs, PBDDs, MoBPCDDs and MoBPCDFs in this order. Levels of PBDD/Fs were generally 1-2 orders of magnitude lower than chlorinated analogues. Levels of PCDDs are higher than PCDFs in Hong Kong while levels of PBDFs are higher than PBDDs in Korea (p<0.05). Report of PBDD/Fs and MoBPCDD/Fs in sediments from East Asian countries is novel and original. Environmental levels of PBDD/Fs are supposed to start increasing in accordance with rising production, use and disposal of brominated flame retardants (BFRs) and recycling processes of e-waste in Asian developing countries.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Food Contamination; Geologic Sediments; Hong Kong; Industrial Waste; Korea; Oceans and Seas; Polybrominated Biphenyls; Polychlorinated Biphenyls; Soil Pollutants

Formation of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), benzenes (PCBz), and phenols (PCPh) was studied during combustion of an artificial municipal solid waste (MSW) in a laboratory-scale fluidized-bed reactor with simultaneous collection of flue gas samples at three different temperatures in the post-combustion zone (450 degrees C, 300 degrees C, and 200 degrees C). PCDF, PCBz, and PCPh were predominantly formed at or above the first sampling point (450 degrees C) with a dominance of the lower chlorinated homologues. PCDDs, on the other hand, were dominated by the intermediately chlorinated homologues with concentrations peaking at 300 degrees C. The dominating PCPh congeners clearly displayed the ortho-para directionality, which is indicative of electrophilic aromatic substitution, as did the PCBz isomer distribution patterns to some extent. Comparison of the observed PCBz isomer distribution patterns to prior work may indicate coupling of aliphatic species in chlorobenzene formation. The PCDDs seemed to be largely influenced by chlorophenol condensation reactions and to some extent chlorination reactions, while the PCDFs displayed a chlorination-oriented pattern for the mono- to tri-chlorinated homologues and a PCPh condensation pattern for the higher chlorinated homologues. Injection of non-chlorinated dibenzo-p-dioxin at 650 degrees C resulted in increased formation of Tri-HxCDD and a decrease in the dibenzofuran levels. The affected PCDD and PCDF congeners were not products expected to form from chlorine substitution, but instead are well known chlorophenol condensation products.

Topics: Air Pollutants; Benzene Derivatives; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Hot Temperature; Incineration; Isomerism; Phenols; Polychlorinated Dibenzodioxins; Refuse Disposal

Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) were measured in muscle-blubber biopsy samples from 21 Galapagos sea lion (Zalophus wollebaeki) pups that were live captured in the Galapagos Islands (Ecuador) using gas chromatography/high-resolution mass spectrometry. Only traces of PBDEs were detected in one male pup, whereas PCDDs and PCDFs were not detected in any sample. The total concentration of PCBs (ΣPCB) in the pups averaged 104 μg/kg lipid (range, 49-384 μg/kg). No statistically significant differences in ΣPCB were observed among the four study sites in the Galapagos Islands. Concentrations of PCB congeners in Galapagos sea lion pups were dominated by low-molecular-weight congeners. These results suggest that global transport is the main source for PCBs in Galapagos sea lions. The ΣPCB levels were below immunotoxic and endocrine-disruption thresholds in pinnipeds, suggesting a limited risk of adverse health effects. The present study indicates that Galapagos sea lions can serve as a useful sentinel of pollutants with a long-range transport capacity and that Galapagos Islands are not exempt from the threats of global pollutants despite its remote locale.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Ecuador; Environmental Monitoring; Female; Gas Chromatography-Mass Spectrometry; Halogenated Diphenyl Ethers; Male; Polychlorinated Biphenyls; Quality Control; Regression Analysis; Risk Assessment; Sea Lions; Water Pollutants, Chemical

The impact of dibenzofuran (DF) and dibenzo-p-dioxin (DD) on the changes in bacterial community structure and the transition of catabolic genes were studied using forest soil. The bacterial community structure of soil suspensions amended with 1 microg/g of either DF or DD was analyzed by 16S rRNA and functional gene sequencing. To analyze the functional genes in the communities, we targeted a gene sequence that functions as the binding site of Rieske iron sulfur center common to ring-hydroxylating dioxygenases (RHDs) for monocyclic, bicyclic, and tricyclic aromatic compounds. The gene fragments were polymerase chain reaction-amplified from DNAs extracted from soil suspensions spiked with either DF or DD, cloned, and sequenced (70 clones). Bacterial community analysis based on 16S rRNA genes revealed that specific 16S rRNA gene sequences, in particular, phylotypes within alpha-Proteobacteria, increased in the soil suspension amended with DF or DD. RHD gene-based functional community analysis showed that, in addition to two groups of RHD genes that were also detected in unamended soil suspensions, another two groups of RHD genes, each of which is specific to DF- and DD-amended soil, respectively, emerged to a great extent. The DD-specific genotype is phylogenetically distant from any known RHDs. These results strongly suggest that soil microbial community potentially harbors a wide array of organisms having diverse RHDs including those previously unknown, and that they could quickly respond to an impact of contamination of hazardous chemicals by changing the microbial community and gene diversity.

Topics: Bacteria; Base Sequence; Benzofurans; Biodiversity; Dioxins; Dioxygenases; Electron Transport Complex III; Genes, Bacterial; Hydroxylation; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Soil; Soil Microbiology; Trees

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (dl-PCBs) are a family of chemically-related lipophilic compounds characterized by similar toxicity. Due to their properties they are universally distributed in the environment and classified as persistent organic pollutants (POPs). From most of studies carried out to evaluate human dietary intake, milk and dairy products result as a major contributors of PCDD/Fs uptake. Of course the main source of milk contamination is animal feeds. Lactating ruminants, cows included, transfer these compounds to the food chain by ingestion of contaminated vegetables or soil. Their resistance to degradation and a high lipophilicity means that PCDD/Fs and dl-PCBs may be accumulated into fat tissues from which they are transferred to milk during lactation period. Seventy-nine cows milk samples, collected in the monitoring plan 2008, were analyzed for PCDD/Fs and dl-PCBs. Eleven milk samples were non-compliant corresponding to five breeding livestock located in Caserta province. The distribution of PCDD/Fs and dl-PCBs congeners in these samples was examined in order to determine the likely sources of dioxins. The results show that the congener profile is characterized by a prevalence of PCDFs in respect of PCDDs, that represents the typical pattern of thermal origin contamination.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Environmental Pollutants; Italy; Milk; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

Here we analyze the potential of black carbon (BC) and oil-inclusive models to explain in situ sorption of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), organochlorine pesticides (OCP), polychlorobiphenyls (PCB), polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF) to harbor sediments. Such models are important to understand bioavailability and mobility limitations of these chemicals in the aquatic environment. Separate BC- or oil-inclusive models have been described before. However, it is unclear whether oil could dominate in situ sorption in sediments that also contain BC, and whether the relative importance of phases would differ for different compounds. A BC- and oil-inclusive model was evaluated against chemical data and measured sediment characteristics. Parameter uncertainty was assessed using Monte Carlo simulations. Fitted model parameters were consistent with literature data and were satisfactory from a statistical as well as a chemical perspective. Sorption to oil was strong, proportional to octanol-water partitioning (Log K(ow)) and of similar magnitude for OCP, PCB, PCDD, and PCDF. For PAH a single oil sorption coefficient was found. Oil dominated sorption only for PCBs, at oil levels above 50-250 mg oil/kg sediment. BC dominated sorption of most other compounds, especially high molecular PAHs, PCDD, and PCDFs.

Topics: Adsorption; Benzofurans; Dibenzofurans, Polychlorinated; Dichlorodiphenyl Dichloroethylene; Dichlorodiphenyldichloroethane; Dioxins; Geologic Sediments; Models, Chemical; Oils; Pesticides; Polychlorinated Biphenyls; Regression Analysis; Solid Phase Extraction; Soot; Water

This study focuses on the atmospheric deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) on the soils in the vicinity of two municipal solid waste incinerators (MSWIs), which were located in the Gangshan (GS) and the Renwu (RW) Townships of southern Taiwan. PCDD/Fs in the soils were sampled simultaneously with those in the ambient air and analyzed for 17 2,3,7,8-substituted PCDD/Fs. The results show that the mean contents of PCDD/Fs in the soils near MSWI-GS and MSWI-RW were 2.65 and 1.20 ng I-TEQ/kg dry weight, respectively. Annual wet deposition fluxes of total PCDD/Fs were 119 and 113 ng/m(2)-year in the ambient air near MSWI-GS and MSWI-RW, respectively. The results obtained in this study are much higher than those estimated for the Atlantic Ocean, where the average wet deposition was only 45 ng/m(2)-year. The annual dry deposition fluxes accounted for 58.2 and 66.7%, respectively, indicating that dry deposition was more dominant than wet deposition in the atmospheric deposition processes. The congener profiles of 17 2,3,7,8-substituted PCDD/Fs showed that OCDD dominates in the soils. The contributions of OCDD in the soils near MSWI-GS and MSWI-RW were 73.4 and 67.1%, respectively, while they were only 41.4 and 31.2% in the atmospheric deposition, respectively. These results imply that OCDD is more persistent in the environment than other congeners. The results of the present study strongly suggest that exposure to PCDD/Fs in these areas should be reduced.

Topics: Air Pollutants; Benzofurans; Dioxins; Environmental Exposure; Environmental Monitoring; Refuse Disposal; Soil; Taiwan

A novel black carbon (BC) inclusive modeling tool is applied to estimate the distribution and long-term fate of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Norwegian Grenland Fjords. Three versions of the model were developed in which sediment-water partitioning was described using (i) an amorphous organic carbon (AOC) partitioning sorption model without BC sorption, (ii) a combined AOC and BC sorption model based on the Freundlich isotherm, and (iii) a combined BC-AOC model based on the Langmuir isotherm. The predictive ability of the three different models was evaluated for 17 PCDD/Fs by comparison of model predictions with observed organic carbon normalized sediment-water partition coefficients (K(TOC)) and with measured concentrations. All three versions of the model were able to predict concentrations that were in reasonable agreement with measured particulate concentrations (i.e., within a factor of 4 of median values). Estimated particulate concentrations were less sensitive to the model choice because the majority of the mass of these hydrophobic chemicals is associated with particulates regardless. However, for estimation of K(TOC) or dissolved water concentrations, both versions of the combined AOC and BC sorption models provided greatly improved estimates compared to the AOC-only model.

Topics: Benzofurans; Carbon; Dioxins; Environmental Monitoring; Models, Theoretical; Water Pollutants, Chemical

Catechol has been identified as one of the most abundant organic products in tobacco smoke and a major molecular precursor for semiquinone type radicals in the combustion of biomass material. The high-temperature gas-phase pyrolysis of catechol under hydrogen-rich and hydrogen-lean conditions was studied using a fused-silica tubular flow reactor coupled to an in-line GC/MS analytical system. Thermal degradation of catechol over temperature range of 250-1000 degrees C with a reaction time of 2.0s yielded a variety products including phenol, benzene, dibenzofuran, dibenzo-p-dioxin, phenylethyne, styrene, indene, anthracene, naphthalene, and biphenylene. Ortho-benzoquinone which is typically associated with the presence of semiquinone radicals was not observed and is proposed to be the result of fast decomposition reactions that lead to a variety of other reaction products. This is in contrast to the decomposition of hydroquinone that produced para-benzoquinone as the major product. A detailed mechanism of the degradation pathway of catechol is proposed.

Topics: Benzofurans; Benzoquinones; Catechols; Dioxins; Gas Chromatography-Mass Spectrometry; Hot Temperature

Television (TV) set components are highly flame resistant, with their added brominated compounds such as polybrominated diphenyl ethers (PBDEs). These compounds might be released indoors via dust, which presents a potential exposure pathway for humans in the home environment. In this study, we collected dust from inside TV sets and TV set component samples (parts of housing front cabinets, rear cabinets and circuit boards) of five sets used in Japan. We measured BFRs (i.e., PBDEs, tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs)) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/DFs). Analytical results of the TV components showed that the concentrations of PBDEs, TBBPA and PBDFs (48,000 microg/g, 19,000 microg/g and 9600 ng/g as mean values, respectively) were all highest in the rear cabinets. The SigmaPBDD concentrations (460 ng/g as a mean value) detected were highest in the circuit board samples. The respective SigmaPBDE and SigmaPBDF concentrations in the dust samples were 67-500 microg/g (mean 300 microg/g) and 180-650 ng/g (mean 410 ng/g). Such concentrations were 2-3 orders of magnitude higher than those previously reported for house dust samples, which suggests that the brominated compounds are transferred from TV components into dust. Comparison of congener patterns of the brominated compounds in the dust identified the components as the source of these BFRs.

Topics: Benzofurans; Dioxins; Dust; Environmental Pollutants; Flame Retardants; Hydrocarbons, Brominated; Polybrominated Biphenyls; Television

The dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in terms of toxic equivalents (TEQs) was investigated in Swedish children and young adults. Exposure was estimated from concentration data of six groups of individual food commodities (meat, fish, dairy products, egg, edible fats and other foodstuff) combined with food intake data from a 7-day record book obtained from 670 individuals aged 1-24 years. The results showed that Swedish boys and girls, up to the age of ten, had a median TEQ intake that exceeded the tolerable daily intake (TDI) of 2 pg TEQ/kg body weight. Children exceeding the TDI varied from almost all individuals among the youngest children to about 20% among young men and women. Dairy and fish products were the main sources of exposure for the average child, accounting for 59% of the total TEQ intake. The individuals most highly exposed were, on the other hand, characterized by a high consumption of fish. Since children constitute a vulnerable group, results obtained from the present study show that it is essential to perform age specific dietary intake assessments of pollutants and more carefully consider sensitive and/or highly exposed groups in the population in the risk management processes.

Topics: Adolescent; Benzofurans; Body Burden; Child; Child, Preschool; Dairy Products; Dibenzofurans, Polychlorinated; Diet; Diet Records; Dioxins; Environmental Exposure; Environmental Pollutants; Female; Food Analysis; Food Contamination; Humans; Infant; Male; Meat; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Seafood; Sweden; Young Adult

Fly ash and ambient emissions of municipal solid waste incinerators contain polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), other organic compounds, metals, and gases. Hazardous substances such as PCDD/Fs, mercury vapors and other silicates, and the components of bottom ash and fly ash elevate the oxidative damage. We compared oxidative damage in workers exposed to hazardous substances at a bottom ash recovery plant and 3 fly ash treatment plants in Taiwan by measuring their levels of plasma malondialdehyde (MDA) and urine 8-hydroxydeoxyguanosine (8-OH-dG). Significantly higher MDA levels were found in fly ash treatment plant workers (3.20 microM) than in bottom ash plant workers (0.58 microM). There was a significant association between MDA levels in workers and their working environment, especially in the fly ash treatment plants. Levels of 8-OH-dG varied more widely in bottom ash workers than in fly ash workers. The association between occupational exposure and 8-OH-dG levels may be affected by the life style of the workers. Because more dioxins and metals may leach from fly ash than from bottom ash, fly ash treatment plant workers should, as much as possible, avoid exposing themselves to fly ash.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Benzofurans; Biomarkers; Carbon; Coal Ash; Deoxyguanosine; Dioxins; Environment; Female; Fraxinus; Hazardous Waste; Humans; Incineration; Industrial Waste; Lipid Peroxidation; Male; Malondialdehyde; Metallurgy; Middle Aged; Occupational Exposure; Oxidative Stress; Particulate Matter; Polycyclic Aromatic Hydrocarbons; Taiwan; Workplace; Young Adult

Environmental pollution arising from electronic waste (e-waste) disposal and recycling has received considerable attention in recent years. Treatment, at low temperatures, of e-wastes that contain polyvinylchloride and related polymers can release polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Although several studies have reported trace metals and polybrominated diphenyl ethers (PBDEs) released from e-waste recycling operations, environmental contamination and human exposure to PCDD/Fs from e-waste recycling operations are less well understood. In this study, electronic shredder waste and dust from e-waste facilities, and leaves and surface soil collected in the vicinity of a large scale e-waste recycling facility in Taizhou, Eastern China, were analyzed for total PCDD/ Fs including 2,3,7,8-substituted congeners. We also determined PCDD/Fs in surface agricultural soils from several provinces in China for comparison with soils from e-waste facilities. Concentrations of total PCDD/Fs were high in all of the matrices analyzed and ranged from 30.9 to 11400 pg/g for shredder waste, 3460 to 9820 pg/g dry weight for leaves, 2560 to 148000 pg/g dry weight for workshop-floor dust, and 854 to 10200 pg/g dry weight for soils. We also analyzed surface soils from a chemical industrial complex (a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant) in Shanghai. Concentrations of total PCDD/Fs in surface soil (44.5-531 pg/g dry wt) from the chemical industrial complex were lower than the concentrations found in soils from e-waste recycling plants, but higher than the concentrations found in agricultural soils. Agricultural soils from six cities in China contained low levels (3.44-33.8 pg/g dry wt) of total PCDD/Fs. Profiles of dioxin toxic equivalents (TEQs) of 2,3,7,8-PCDD/Fs in soils from e-waste facilities in Taizhou differed from the profiles found in agricultural soils. The estimated daily intakes of TEQs of PCDD/ Fs via soil/dust ingestion and dermal exposure (2.3 and 0.363 pg TEQ/kg bw/day for children and adults, respectively) were 2 orders of magnitude higher in people at e-waste recycling facilities than in people at the chemical industrial site (0.021 and 0.0053 pg TEQ/kg bw/day for children and adults, respectively), implying greater health risk for humans from dioxin exposures at e-waste recycling facilities. The calculated TEQ exposures for e-waste workers from dust and soil ingestion alone were 2-3 orders of magnitude grea

Topics: Adult; Benzofurans; Child; China; Conservation of Natural Resources; Dioxins; Electronics; Environmental Monitoring; Environmental Pollutants; Humans; Hydrocarbons, Chlorinated; Industrial Waste; Industry

Annual emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from open burning of crop residues in each province of China mainland between 1997 and 2004 were estimated to be ranged from 1.38x10(3) to 1.52x10(3) g I-TEQ/yr, with the average of 1.50+/-0.08x10(3) g I-TEQ/yr, which contributed to approximately 10% approximately 20% of the total emissions in China. The PCDD/F emissions mainly occurred in the largest crop-producing provinces, especially in those of higher economic levels. The major sources of PCDD/F emissions from open burning in China were found to be cereal residues (i.e. rice, wheat, and corn), which accounted about 70% of the total emissions. Moreover, the first-order one-variable grey differential equation model (GM (1,1) model) for annual emissions of PCDD/Fs was established based on grey system theory. The GM (1,1) model was proved to be robust to predict the annual PCDD/F emissions from crop residue field burning in forthcoming years.

Topics: Agriculture; Air Pollutants; Benzofurans; China; Dioxins; Environmental Monitoring; Incineration; Models, Theoretical; Oryza; Polychlorinated Biphenyls; Triticum; Zea mays

Formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and chlorinated phenols on CuCl(2) from unsubstituted phenol and three monochlorophenols was studied in a flow reactor over a temperature range of 100-425 degrees C. Heated nitrogen gas streams containing 8.0% oxygen were used as carrier gas. The 0.00024mol of unsubstituted phenol and 0.00039mol of each monochlorophenol were passed through a 1g and 1cm SiO(2) particle containing 0.5% (Cu by mass) CuCl(2). Chlorination preferentially occurred on ortho-(2, 6) and para-(4) positions. Chlorination increased up to 200 degrees C, and thereafter decreased as temperature increased. Chlorination of phenols plays an important role in the formation of the more chlorinated PCDD/Fs. Chlorinated benzenes are formed possibly from both chlorination of benzene and chlorodehydroxylation of phenols. Chlorinated phenols with ortho chlorine formed PCDD products, and major PCDD products were produced via loss of one chlorine. For PCDF formation, at least one unchlorinated ortho carbon was required.

Topics: Benzene; Benzofurans; Catalysis; Copper; Dibenzofurans, Polychlorinated; Dioxins; Hot Temperature; Molecular Structure; Oxidation-Reduction; Phenols; Polychlorinated Dibenzodioxins

Polychlorinated dibenzo-p-dioxins and dibenzofurans in crude extracts of fly ash and flue gas from municipal waste incinerators were quantified using a comprehensive multidimensional gas chromatograph (GC x GC) coupled to a high-resolution time-of-flight mass spectrometer (HR-TOFMS). For identification and quantification, we developed our own program to prepare 3D chromatograms of selected mass numbers from the data of the GC x GC/HR-TOFMS. Isolation of all congeners with a TCDD toxic equivalency factor from the other isomers by only one injection was confirmed. The instrumental detection limit of TCDD on the GC x GC/HR-TOFMS was 0.9 pg by the relative calibration method. Quantification of these substances in the crude extracts was achieved by direct injection to the GC x GC/HR-TOFMS. The results agree with the values obtained using a generic gas chromatography/high-resolution mass spectrometry (GC/HRMS) system. It was confirmed that measurement by high-resolution TOFMS and GC x GC effectively reduces interference from other chemicals.

Topics: Benzofurans; Carbon; Coal Ash; Dioxins; Gas Chromatography-Mass Spectrometry; Particulate Matter

The concentration of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined in soils and different species of vegetation collected from the Dongting Lake region, China. Use of sodium pentachlorophenate (Na-PCP) was the main contamination source of PCDD/Fs for soil/sediment and vegetation in the Dongting Lake region. Reed (Phragmitas communis Trin), Polygonum orientale L., and Artemisia selengensis Turcz ex Bess were selected as model plants to explore the pathway of PCDD/Fs transfer from contaminated soil to vegetation. In the vegetation tissue samples, the total international toxic equivalency values ranged from 0.14 to 1.64 pg international toxic equivalency/g dry weight with a mean value of 0.67 pg international toxic equivalency/g dry weight. Polychlorinated dibenzo-p-dioxins and dibenzofurans congener distribution and bioaccumulation varied among vegetation species. Polychlorinated dibenzo-p-dioxins and dibenzofuran levels in the leaves were found to be higher than those in the root and stem, which were affected considerably by volatilization from contaminated soil. Volatilization from polluted soil and subsequent sorption to leaves may be a significant pathway for contamination of vegetation in Dongting Lake region.

Topics: Benzofurans; China; Dioxins; Environmental Monitoring; Pentachlorophenol; Plant Structures; Plants; Polychlorinated Dibenzodioxins; Soil Pollutants; Tissue Distribution; Volatilization

Two gas chromatography-mass spectrometry systems equipped with an ion-trap mass analyzer working in tandem mode (GC-MS-MS) were evaluated for the determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in food samples. The performance of the two ion-trap instruments, which dispose of an external ion source (ThermoFinnigan GCQ/Polaris) and internal ionization (Varian Saturn 2,200), have been compared in terms of linearity, repeatability, limit of detection and long-term precision. Both instruments provided similar run-to-run and day-to-day precisions, ranging from 2% to 8% and between 2% and 13%, and instrumental limits of detection between 0.09 and 0.36 pg injected for PCDD/Fs and from 0.03 to 0.09 pg injected for dioxin-like PCBs. Although both instruments seem to be suitable for food analysis, only the use of external ionization allowed to achieve reliable results for PCDD/F determination at concentrations close to the maximum residue levels established by the EU for foods. Internal ionization provides high limits of detection (from 10- to 30-fold higher) and worse precision (RSD, 14-43%). In contrast, for dioxin-like PCBs both instruments allowed to obtain excellent results with precisions lower than 15%.

Topics: Animals; Benzofurans; Chickens; Chromatography, Gas; Dioxins; Fish Oils; Food Analysis; Polychlorinated Biphenyls; Quality Control; Solutions; Tandem Mass Spectrometry

This study determines spatial trends and congener patterns of 2378-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surficial sediments of Lakes Erie and Ontario. Sediments are enriched in 2378-PCDFs in Lake Ontario, and the PCDD/F concentrations increased from shallow near-shore sediments towards deep-water depositional zone sediments. In Lake Erie, sediments were dominated by octachlorodibenzo-p-dioxin, and the highest PCDD/F concentrations were observed in the western basin and the southern shoreline of the central basin with a decrease towards the eastern basin and the northern shoreline of the central basin. Principal components analysis revealed that chemical manufacture and disposal of chemical waste along the Niagara River has been a major PCDD/F source to Lake Ontario; while PCDD/Fs in Lake Erie are from multiple sources including industrial sources along the Detroit River, major tributaries along the southern shoreline of the lake, and atmospherically-derived material from the upper lakes and connecting channels.

Topics: Benzofurans; Canada; Dibenzofurans, Polychlorinated; Dioxins; Environmental Monitoring; Fresh Water; Geologic Sediments; Industrial Waste; Polychlorinated Dibenzodioxins; Rivers; Soil Pollutants; Water Pollutants, Chemical

Rhodococcus sp. strain HA01, isolated through its ability to utilize dibenzofuran (DBF) as the sole carbon and energy source, was also capable, albeit with low activity, of transforming dibenzo-p-dioxin (DD). This strain could also transform 3-chlorodibenzofuran (3CDBF), mainly by angular oxygenation at the ether bond-carrying carbon (the angular position) and an adjacent carbon atom, to 4-chlorosalicylate as the end product. Similarly, 2-chlorodibenzofuran (2CDBF) was transformed to 5-chlorosalicylate. However, lateral oxygenation at the 3,4-positions was also observed and yielded the novel product 2-chloro-3,4-dihydro-3,4-dihydroxydibenzofuran. Two gene clusters encoding enzymes for angular oxygenation (dfdA1A2A3A4 and dbfA1A2) were isolated, and expression of both was observed during growth on DBF. Heterologous expression revealed that both oxygenase systems catalyze angular oxygenation of DBF and DD but exhibited complementary substrate specificity with respect to CDBF transformation. While DfdA1A2A3A4 oxygenase, with high similarity to DfdA1A2A3A4 oxygenase from Terrabacter sp. strain YK3, transforms 3CDBF by angular dioxygenation at a rate of 29% +/- 4% that of DBF, 2CDBF was not transformed. In contrast, DbfA1A2 oxygenase, with high similarity to the DbfA1A2 oxygenase from Terrabacter sp. strain DBF63, exhibited complementary activity with angular oxygenase activity against 2CDBF but negligible activity against 3CDBF. Thus, Rhodococcus sp. strain HA01 constitutes the first described example of a bacterial strain where coexpression of two angular dioxygenases was observed. Such complementary activity allows for the efficient transformation of chlorinated DBFs.

Topics: Benzofurans; Dioxins; Dioxygenases; DNA, Bacterial; DNA, Ribosomal; Gene Expression Profiling; Magnetic Resonance Spectroscopy; Molecular Sequence Data; Multigene Family; Oxidation-Reduction; Phylogeny; Reverse Transcriptase Polymerase Chain Reaction; Rhodococcus; RNA, Ribosomal, 16S; Salicylates; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Substrate Specificity

The aim was to determine the body burden of dioxins and polychlorinated biphenyls (PCBs) and whether they are associated with variables influencing reproduction. Our subjects were healthy women (mean age of 29 [SD=4.5]) from central Taiwan. The congeners of dioxins and dioxin-like PCBs in placentas (n=119) were identified using gas chromatography/high resolution mass spectrometry. The median levels of polychlorinated dibenzo-p-dioxins/dibenzofurans and PCBs were 10.2 (geometric mean [GM]: 9.8, 95% confidence interval [95% CI]: 8.8-10.9) and 2.7 (GM: 2.7, 95% CI: 2.3-3.1) pg WHO-TEQ/g lipid, respectively. Total TEQ level in placentas was significantly correlated with mothers' arm circumference (r=0.22, p=0.043). Increased body fat percentage was associated with higher total TEQ level in placentas. After adjustment for maternal age, pre-pregnant body mass index (BMI), and parity, placental dioxin-TEQ level higher in women (age 19 years) with irregular menstrual cycle than in those (age <18 years) with regular menstrual cycle (p=0.032) and placental PCB-TEQ level was higher in women with menstrual cycles longer than 33 days versus less than 33 days (p=0.006). Thus, environmental exposure to dioxins and PCBs may be related to changes in current menstrual cycle characteristics.

Topics: Adipose Tissue; Adult; Age Factors; Analysis of Variance; Benzofurans; Body Burden; Confidence Intervals; Dioxins; Environmental Exposure; Environmental Pollutants; Female; Gas Chromatography-Mass Spectrometry; Humans; Menarche; Menstrual Cycle; Placenta; Polychlorinated Biphenyls; Pregnancy; Prenatal Exposure Delayed Effects; Surveys and Questionnaires; Taiwan

Selective pressurized liquid extraction (PLE) of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from various food and feed samples was performed with a selective PLE method previously developed for bulk PCBs. The method utilizes sulfuric acid impregnated silica inside the extraction cell to oxidize coextracted fat. Extractions were performed at 100 degrees C with n-heptane for 5 min in two cycles. Data obtained by selective PLE combined with gas chromatography/high-resolution mass spectrometry (GC-HRMS) were compared to concentrations derived from reference laboratories applying conventional sample preparation and GC-HRMS. Experiments performed on spiked vegetable oil, naturally contaminated crude fish oil and oil containing compound feed samples showed good results for these relatively simple matrices. The accuracy was generally +/-20% as compared to spiked levels or to values obtained by the reference laboratories. The precision, measured as the relative standard deviation (RSD) for 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalency values (TEQs), was below 10% in all cases. The method was also tested on naturally contaminated herring tissue, chicken tissue, pork tissue and sepiolitic clay, which all caused some trouble. It was observed that sufficient amounts of sodium sulfate should be used for dehydration of tissue samples and additionally, the cells should not be packed too dense in order to avoid suppressed extraction efficiency. Once this was attended to, satisfactory data could be obtained, except for sepiolithic clay. This study demonstrates that selective PLE can be applied with success to a number of food and feed matrices in analysis of PCDD/Fs and dl-PCBs. Since the fat removal step is on-line, the selective PLE method will reduce time and solvent consumption for sample preparation as compared to traditional clean-up.

Topics: Benzofurans; Dioxins; Food Analysis; Gas Chromatography-Mass Spectrometry; Meat Products; Plant Oils; Polychlorinated Biphenyls; Reproducibility of Results

The applicability of 13 different GC columns (Agilent HP-5MS, Restek Rtx-5MS, Rtx-Dioxin2, Supelco Equity 5, SP-2331, Varian VF-5MS, CP-Sil 8 CB LowBleed/MS, J&W Scientific DB-5, DB-225, DB-XLB, DB-5MS, Phenomenex ZB-5MS, and ZB-5UMS) for US Environmental Protection Agency (EPA) methods 1613b, 8290 and European Standard Method EN 1948 for measurement of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) has been evaluated for the separation of all International Toxic Equivalent Factor (I-TEF) isomers (tetra- through octachlorinated at 2,3,7,8 positions) from closely eluting isomers using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). The relative performance data are compared based on mass chromatograms using a "visualization approach", absolute retention times, 2,3,7,8-substituted, total dioxins and furans concentrations, as well as TEQ comparisons. None of the columns tested were able to separate all 17 I-TEFs from other co-eluted isomers. Our data indicate that all I-TEFs isomers can be fully differentiated from closely eluting isomers using either of two sets of non-polar and polar stationary phase combinations. One set consists of DB-5 (HP-5MS, Rtx-5MS, Equity-5) and DB-225 GC columns and another set would have a combination of DB-5MS (ZB-5MS, VF-5MS, CP-Sil 8 CB LowBleed/MS) with SP-2331. However, depending on the source of PCDDs/PCDFs a laboratory could choose a single GC column that separates the 2,3,7,8-substituted congeners that contribute most significantly to the overall TEQ. These data are the most comprehensive to date, provide a valuable addition to operational criteria for the standard EPA methods 1613b, 8290, European Standard Method EN 1948 and will allow researches to compare data generated according to the different compliance analytical procedures.

Topics: Benzofurans; Chromatography, Gas; Dioxins; Mass Spectrometry; Polychlorinated Dibenzodioxins

The results of this study provide a measure of the levels of dioxin-like compounds (polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls) in pooled blood serum collected throughout Australia in 2003. De-identified samples selected from surplus pathology samples were stratified on the basis of gender, region and age. In total 9090 samples were collected and analysed as 96 pools. Dioxin-like chemicals were detected in all strata. The mean and median levels expressed as TEQ values for all pooled samples were 10.9+/-1.0 pg TEQ g(-1) lipid and 8.3 pg TEQ g(-1) lipid. For males and females the mean levels were 10.4+/-0.6 pg TEQ g(-1) lipid and 11.5+/-1.5 pg TEQ g(-1) lipid, respectively. A direct relationship of increasing dioxin-like chemical levels with increasing age was observed and could be described by the following equation: Levels in blood expressed as pg TEQ g(-1) lipid = 3.3 exp(0.0251 age) (r2 = 0.87). No significant differences were observed in the levels of dioxin-like chemicals in samples collected from males and females. In addition, the levels of dioxin-like chemicals across the five regions were similar within each age range. In summary, the levels of dioxin-like chemicals in the Australian population are low compared to international levels and are similar across all regions of Australia within each designated age range. The levels of these chemicals increase with age and can be estimated if the age of an individual is known.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Australia; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Environmental Exposure; Environmental Pollutants; Female; Housing; Humans; Male; Middle Aged; Polychlorinated Biphenyls; Population Surveillance; Risk Assessment; Sex Factors

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Topics: Agriculture; Air; Benzofurans; Dioxins; Ecosystem; Industrial Waste; Polychlorinated Dibenzodioxins; Soil; Soil Pollutants; Taiwan; Urbanization

Sphingomonas wittichii RW1 degrades chlorinated dibenzofurans and dibenzo-p-dioxins via meta cleavage. We used inverse PCR to amplify dxnB2, a gene encoding one of three meta-cleavage product (MCP) hydrolases identified in the organism that are homologues of BphD involved in biphenyl catabolism. Purified DxnB2 catalyzed the hydrolysis of 8-OH 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate (HOPDA) approximately six times faster than for HOPDA at saturating substrate concentrations. Moreover, the specificity of DxnB2 for HOPDA (k(cat)/K(m) = 1.2 x 10(7) M(-1) s(-1)) was about half that of the BphDs of Burkholderia xenovorans LB400 and Rhodococcus globerulus P6, two potent polychlorinated biphenyl (PCB)-degrading strains. Interestingly, DxnB2 transformed 3-Cl and 4-OH HOPDAs, compounds that inhibit the BphDs and limit PCB degradation. DxnB2 had a higher specificity for 9-Cl HOPDA than for HOPDA but a lower specificity for 8-Cl HOPDA (k(cat)/K(m) = 1.7 x 10(6) M(-1) s(-1)), the chlorinated analog of 8-OH HOPDA produced during dibenzofuran catabolism. Phylogenetic analyses based on structure-guided sequence alignment revealed that DxnB2 belongs to a previously unrecognized class of MCP hydrolases, evolutionarily divergent from the BphDs although the physiological substrates of both enzyme types are HOPDAs. However, both classes of enzymes have mainly small hydrophobic residues lining the subsite that binds the C-6 phenyl of HOPDA, in contrast to the bulky hydrophobic residues (Phe106, Phe135, Trp150, and Phe197) found in the class II enzymes that prefer substrates possessing a C-6 alkyl. Thr196 and/or Asn203 appears to be an important determinant of specificity for DxnB2, potentially forming hydrogen bonds with the 8-OH substituent. This study demonstrates that the substrate specificities of evolutionarily divergent hydrolases may be useful for degrading mixtures of pollutants, such as PCBs.

Topics: Amino Acid Sequence; Bacterial Proteins; Benzofurans; Cloning, Molecular; Dibenzofurans, Polychlorinated; Dioxins; DNA, Bacterial; Fatty Acids, Unsaturated; Hydrolases; Kinetics; Molecular Sequence Data; Phylogeny; Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sphingomonas; Substrate Specificity

Fly ash from municipal solid waste incineration may catalytically enhance the formation and degradation of chlorinated aromatic compounds. The activities of three Deacon catalysts in this process were investigated in a statistically designed experiment. Chlorides of copper, chromium, and nickel were added to fly ash samples and the resulting samples heated at 300 degrees C for 2 h in an air atmosphere. The addition of copper increases the formation of all chlorinated aromatic compounds except the low chlorinated congeners of polychlorinated dibenzo-p-dioxins and dibenzofurans. The addition of chromium decreased the formation of most chlorinated aromatic compounds except the highest chlorinated species, where it was without effect. The addition of nickel did not show any significant effect. The outcome of the experiment can be interpreted as two competing processes: the chlorination of aromatic rings and the oxidation of carbon-carbon and carbon-oxygen bonds. The delicate balance between chlorination and oxidation could probably be further exploited to minimize both the emissions and the net production of chlorinated aromatic compounds from combustion.

Topics: Analysis of Variance; Benzofurans; Carbon; Catalysis; Chromium; Coal Ash; Confidence Intervals; Copper; Dioxins; Hydrocarbons, Chlorinated; Particulate Matter; Regression Analysis

Fish from Dutch markets were analysed for concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and compared with the new European maximum residue levels (MRLs), set in 2006. In a first study on 11 different fish and shellfish from various locations, concentrations of PCDD/Fs were nearly all below the MRL for PCDD/Fs [4 pg toxic equivalents (TEQ) per gram wet weight (ww)] and nearly all below 8 pg total TEQ/g ww, the new MRL for the sum of PCDD/Fs and DL-PCBs. Some samples exceeded the total TEQ MRL, such as anchovy, tuna and sea bass. Furthermore, 20 (out of 39) wild eel samples exceeded the specific MRL for eel (12 pg total TEQ/g ww), as the study revealed PCDD/F TEQ levels of 0.2-7.9 pg TEQ/g ww and total TEQ values of 0.9 to 52 pg/g ww. TEQ levels in farmed and imported eel were lower and complied with the MRLs. Smoking eel, a popular tradition in the Netherlands, only had marginal effects on PCDD/F and DL-PCB concentrations. Owing to volatilization, concentrations of lower-chlorinated PCBs were reduced to below the limit of quantification after smoking. DL-PCBs contributed 61-97% to the total TEQ in all eel samples. This also holds for other fish and shellfish (except shrimps): DL-PCB contributed (on average) from 53 (herring) to 83% (tuna) to the total TEQ. Principal-component analysis revealed distinctive congener profiles for PCDD/Fs and non-ortho PCBs for mussels, pikeperch, herring and various Mediterranean fish. The application of new TCDD toxic equivalency factors (TEFs) set by the World Health Organization in 2006 (to replace the 1997 TEFs) resulted in lower TEQ values, mainly owing to a decreased mono-ortho PCB contribution. This decrease is most pronounced for eel, owing to the relative high mono-ortho PCB concentrations in eel. Consequently, a larger number of samples would comply with the MRLs when the new TEFs are applied. The DR CALUX(R) assay may be used for screening total TEQ levels in eel, in combination with gas chromatography-high resolution mass spectrometry confirmation of suspected samples. An almost 1:1 correlation was found when the 1997 TEFs were applied, but, surprisingly, a 1.4-fold overestimation occurred with application of the 2006 TEFs.

Topics: Animals; Benzofurans; Biological Assay; Biphenyl Compounds; Dioxins; Fishes; Food Analysis; Hydrocarbons, Chlorinated; Netherlands; Shellfish; Smoking; Time Factors; World Health Organization

A density functional theory (DFT) study was carried out to investigate possible reactions of dibenzofuran (DF) and dibenzo-p-dioxin (DD) in a reducing environment. Reaction energies, barrier heights, and molecular parameters for reactants, intermediates, products, and transition states have been generated for a wide range of possible reactions. It was found that C-O beta-scission in DF incurs a very large energy barrier (107 kcal/mol at 0 K), which is just 3 kcal/mol less than the direct H fission from C-H in DF to form dibenzofuranyl radicals. It was found that DF allows direct H addition to C1-C4 and C6-C9 as well as addition of two H atoms from a hydrogen molecule at sites 1 and 9 of DF. A bimolecular reaction of DF with H or H2 is found to have a significantly lower barrier than unimolecular decomposition through C-O beta-scission. An explanation for the predominance of polychlorinated dibenzofurans (PCDF) over polychlorinated dibenzo-p-dioxins (PCDD) in municipal waste pyrolysis is presented in the view of the facile conversion of DD into DF through ipso-addition at the four C sites of the two C-O-C central bonds in DD.

Topics: Air Pollutants; Algorithms; Benzofurans; Carbon; Cities; Dioxins; Free Radicals; Hydrogen; Incineration; Models, Theoretical; Molecular Structure; Refuse Disposal; Thermodynamics

The aim of this study was to examine the relationship between placental polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCBs) toxic equivalent (TEQ) levels and the consumption of various food types in pregnant women from central Taiwan. Placental PCDD/Fs and PCB congener TEQ levels were evaluated in 109 pregnant women and dietary information was obtained by questionnaire. TEQ levels of PCDD/Fs and PCBs were positively associated with age and annual family incomes (p < 0.05). PCDD/F TEQs were significantly associated with freshwater fish and dairy product consumption after adjustment for age and body mass index (BMI) (p < 0.05). For PCB TEQs, significant associations were detected for saltwater fish consumption (p < 0.05). In summary, positive correlations were found between freshwater fish and dairy product intake and PCDD/F levels, and a marginal correlation between saltwater fish intake and the body burden of PCBs in pregnant women from central Taiwan. Risk assessment of PCDD/Fs and PCB in fishery products is warranted in a future study to quantify the benefits of fish consumption during the perinatal period.

Topics: Adult; Benzofurans; Diet; Dioxins; Environmental Exposure; Environmental Pollutants; Female; Food Contamination; Humans; Placenta; Polychlorinated Biphenyls; Pregnancy; Taiwan

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) were detected in sediments from Suzhou Creek with mean concentrations of 478.1, 245.1, and 4727.6 pg/g dw, respectively. WHO-TEQ concentrations of PCDD/Fs in sediments ranged from 2.90 to 13.96 pg/g dw, while TEQ concentrations of PCBs varied from 0.27 to 1.41 pg/g dw. OCDD or HpCDD were the dominant congeners but PeCDF or HpCDD was the major contributor to PCDD/Fs-TEQ in all the sites. For dioxinlike biphenyls, PCB 118 was the major congener while PCB-TEQ was attributable to PCB 126 in all the samples.

Topics: Animals; Benzofurans; China; Dioxins; Geography; Geologic Sediments; Polychlorinated Biphenyls; Rivers; Water Pollutants, Chemical

This study investigated concentrations, contents and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the workplaces of a sintering plant. Air samples were collected from the charging zone, the sintering zones of the sintering grate and the rough roll shredder, and the control room. The charging zone was found to have a higher total suspended particulate (TSP) but lower PCDD/F concentrations (=4969 microg nm(-3) and 7.61 pg nm(-3), respectively) than the sintering zone (=1422-1448 microg nm(-3) and 19.16-23.17 pg nm(-3), respectively). The TSP and PCDD/F concentrations were lowest in the control room (=98 microg nm(-3) and 1.75 pg nm(-3), respectively). However, the above concentrations were within the range of a typical urban-industrial area. Quite similar PCDD/F contents were found in particles in the sintering zones and control room (=11.72-14.30 and 15.85 ng g(-1), respectively) suggesting that the sintering zone and the control room are very similar. In both charging and sintering zones, 2,3,4,7,8-PeCDF contributed 40-60% to the total I-TEQ in both the gas phase and particle phase. However, in control room, both congeners 2,3,4,7,8-PeCDF and 2,3,7,8-TCDD were the main contributors; the later contributed 30% of the total I-TEQ in gas phase. In control room, the contribution of 2,3,7,8-TCDD to the total PCDD/F concentration in the gas phase greatly exceeded that in particle phase (=5.5% and 0.8%, respectively). Therefore, solutions must be sought to avoid the transfer of not only the particle-phase but also the gas-phase PCDD/Fs from the sintering zone to the control room in the future.

Topics: Air Pollutants; Atmosphere; Benzofurans; Dioxins; Environmental Monitoring; Extraction and Processing Industry; Workplace

One landfill site, which co-treated solidified monoliths of fly ash and bottom ash, was investigated comprehensively to characterize its PCDD/F distribution. The solidified monoliths, soil, banyan leaves, groundwater in the monitoring wells and the treated landfill leachates in this landfill site for solidified monoliths of fly ash were all sampled to clarify their PCDD/F characteristics. Although the PCDD/F leaching concentrations were extremely lower than the Taiwan PCDD/F TCLP regulation of solidified monoliths, the PCDD/F contents in the surface soils of the landfill site are 460 times higher than that of urban soils and the highest value is 2.8 times higher than the Taiwan soil regulation (1000 ngI-TEQkg(-1)). The elevated PCDD/F contents in the soil reveal their potential for causing adverse health risk for humans, including the pathway of resuspension of soil particles and volatilization of PCDD/Fs from soil. The PCDD/F concentrations in the groundwater and the treated landfill leachates of the landfill site for solidified monoliths were both higher than that in the control samples, suggesting its potential to be a PCDD/F source of nearby water environment. Without proper control and management, landfill sites for solidified monoliths of fly ash can seriously hazard the surrounding environment, therefore, are important to consider.

Topics: Benzofurans; Carbon; Chlorine; Coal Ash; Dioxins; Particulate Matter; Plant Leaves; Soil; Water

This study was designed to evaluate soil and air (gas and particle) transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to vegetation in residential and industrial areas. In a first part, soil-vegetation transfer was assessed. The levels of PCDD/Fs in 120 soil and 120 herbage samples collected from 1996 to 2002 in an industrial area of Montcada (Barcelona, Spain), near a municipal solid waste incinerator (MSWI), were determined. Some additional individual samples were also evaluated. It was concluded that high soil concentrations, which are not at steady state with the air layer above it, show a tendency for PCDD/Fs to escape via volatilization. In a second part of the study, air-vegetation transfer was examined. PCDD/F concentrations from 24 herbage samples were used, while PCDD/F concentrations were also measured in seven high-volume air samples and seven passive air-vapor samples. Scavenging coefficients (m3 air "sampled"/g grass d.m.) ranged from 1.9 to 11.3 m3/g. A good trend with K(OA) was observed for PCDDs (R=0.82), while it was lower for PCDFs (R=0.55). The current results corroborate that PCDD/F concentrations in vegetation are associated with atmospheric deposition. For the highest substituted PCDD/F congeners, the air-particle uptake from plants is the principal pathway. In regions impacted by combustion emission sources, PCDD/F gas-particle partitioning is influenced by a higher concentration of particles in the air. Particles and associated particle-bound PCDD/Fs would sorb to leaf surfaces, and are subject to removal via wash off. However, in areas where emissions to air are not very notable, vapor absorption would be the principal source of vegetation pollution. The results of this investigation can have a potential interest in risk assessment studies and environmental fate models.

Topics: Benzofurans; Carcinogens, Environmental; Dioxins; Environmental Monitoring; Environmental Pollution; Incineration; Models, Theoretical; Plant Leaves; Plants; Polychlorinated Dibenzodioxins; Rain; Refuse Disposal; Soil Pollutants; Spain; Volatilization

The purpose of this study was to assess the environmental impact of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the vicinity of a new hazardous waste incinerator (HWI) 4 years after regular operation of the facility. A double approach was carried out. The PCDD/F congener profiles corresponding to environmental samples, soil and herbage, collected before the HWI (baseline) and 4 years after starting regular operations, as well as PCDD/F profiles of air emission samples, were compared. The potential health risks (carcinogenic and noncarcinogenic) due to PCDD/F exposure were assessed for adults and children living in the neighborhood of the facility. Human exposure to PCDD/Fs was mainly due to dietary food intake. Comparisons between the PCDD/F congener profiles corresponding to the baseline and current surveys, as well as data concerning the human health risk assessment, indicate that the HWI in question does not cause additional risks to the environment orto the population living in the vicinity of the facility.

Topics: Benzofurans; Dioxins; Environmental Exposure; Environmental Monitoring; Hazardous Waste; Humans; Incineration; Refuse Disposal; Risk Assessment

The levels and homologue profile of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from stack gas of three typical fluidized bed incinerators co-firing municipal solid waste (MSW) with Chinese coal were measured. The PCDD/Fs emission was in the range of 0.0054-0.1961 ng I-TEQ/N m(3). Comparison of PCDD/Fs detection results by HRGC/HRMS and HRGC/LRMS suggested that it was feasible to detect fly ash with high PCDD/Fs concentration by HRGC/LRMS. Several factors on PCDD/Fs emission were discussed. The primary reason for the lower PCDD/Fs emission was the inhibition mechanism of relatively high sulfur in feeding coal on PCDD/Fs formation. The emission results also showed that there was no directly correlation between PCDD/Fs levels and CO, O(2) and HCl concentration in flue gas. It was estimated that about 0.1034 g I-TEQ was annually emitted to atmosphere from the tested three MSW incinerators (total daily treatment capacity is 800 tonnes MSW).

Topics: Benzofurans; China; Cities; Coal; Dioxins; Fires; Porphyrins; Power Plants; Soil Pollutants; Water Pollutants

The effect of water vapor on catalyzed de novo formation of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) was investigated through experiments conducted on a fixed-bed apparatus. The results indicated that water vapor could promote the formation of PCDD and PCDF. The dominant pathway was activating fly ash in this work, while water also reacted with chlorine to change the equilibrium of Deacon reaction, which influenced the final yield of PCDD/PCDF. Also a suppression effect of water on CuCl(2) was found according to the values of the catalysis indicator. It is possible that water reduced the catalysis of CuCl(2) or prevented its direct chlorination. But the overall effect of water on the formation of PCDD and PCDF was promotion rather than inhibition.

Topics: Benzofurans; Catalysis; Copper; Dioxins; Hazardous Substances; Industrial Waste; Polychlorinated Dibenzodioxins; Water

The homogeneous, gas-phase oxidative thermal degradation of a 50:50 mixture of 2-bromophenol and 2-chlorophenol was studied in a 1 cm i.d., fused silica flow reactor at a concentration of 88 ppm, with a reaction time of 2.0 s, over a temperature range of 300 to 1000 degrees C. Observed products in order of decreasing yield included the following: dibenzo-p-dioxin (DD), 4-bromo-6-chlorodibenzofuran (4-B,6-CDF), phenol, 4,6-dibromodibenzofuran (4,6-DBDF), 2,6-dibromophenol, 4,6-dichlorodibenzofuran (4,6-DCDF), 2-bromo-4-chlorophenol, 2,4-dibromophenol, 2-chloro-4-bromophenol, 4-monobromodibenzofuran (4-MBDF), 4-monochlorodibenzofuran (4-MCDF), dibenzofuran (DF), 1-monobromodibenzo-p-dioxin (1-MBDD), 1-monochlorodibenzo-p-dioxin (1-MCDD), 2,4,6-tribromophenol, naphthalene, chloronaphthalene, bromonaphthalene, chlorobenzene, bromobenzene, and benzene. The results are compared and contrasted with previous results reported for the oxidations of pure 2-chlorophenol and 2-bromophenol as well as results for the pyrolysis of the mixture of 2-chlorophenol and 2-bromophenol. 4,6-DBDF and 4,6-DCDF were observed in higher yields than under pyrolytic conditions but considerably less than the yields observed for the individual oxidation of 2-chlorophenol and 2-bromophenol. The effect on chlorine and bromine on the concentration of hydroxyl radical is shown to control the dioxin-to-furan ratio.

Topics: Benzofurans; Chlorophenols; Dioxins; Environment; Gases; Hydroxyl Radical; Models, Chemical; Naphthalenes; Oxygen; Phenols; Polychlorinated Dibenzodioxins; Temperature

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the surrounding environment (outdoor) and workplace air of two municipal solid waste incinerators (MSWIs, T and M) were characterized and compared. T and M represented two typical municipal solid waste incinerators in the north of Taiwan, which have different processes for controlling the PCDD/F emissions. The results of this study are summarized as follows. (1) The total PCDD/F and the total PCDD/F WHO-TEQ concentrations in the workplace air were 5-13 and 5-15 times higher than those in the outdoor air, respectively. Obviously, it is worthwhile to explore more on health risk assessment for exposure of PCDD/Fs emitted from MSWIs, particularly in the workplace air. (2) Mean total PCDD/F I-TEQ concentrations in the outdoor air ranged between 0.0216 and 0.155 pg I-TEQ/Nm(3) and averaged 0.0783 pg I-TEQ/Nm(3) (0.0828 pg WHO-TEQ/Nm(3)) during two seasons for two MSWIs, which were 6.5-fold higher than that of a remote site (0.0119 pg I-TEQ/Nm(3) or 0.0132 pg WHO-TEQ/Nm(3)) in Taiwan. However, the above outdoor air concentration levels in the MSWIs were still much lower than the air quality limitation of PCDD/Fs (0.6 pg I-TEQ/Nm(3)) in Japan []. (3) PCDFs were the primary toxicity distributors for PCDD/Fs in the outdoor air, since the ratios of PCDDs/PCDFs (I-TEQ) at all sampling sites ranged from 0.180 to 0.492 and were less than unity. (4) The OCDD, OCDF, 1,2,3,4,6,7,8-HpCDD and 1,2,3,4,6,7,8-HpCDF were the four dominant species in both workplace and outdoor air near MSWIs. (5) By spraying water on and wetting both the fly and bottom ashes, the mean total PCDD/F I-TEQ concentration in the workplace air was reduced 86.9% in the T MSWI. The above results indicate an appropriate improving action did inhibit the fugitive emission of PCDD/Fs and reduce the health risk of workers during work handling ashes in MSWIs.

Topics: Air Pollutants; Benzofurans; Chlorine; Dioxins; Environmental Monitoring; Incineration; Seasons

A rapid, sensitive and accurate method has been developed for the determination of seventeen 2, 3, 7, 8-substituted congeners of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in sediment using isotope dilution high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Dibenzo-p-dioxins and dibenzo-furans were extracted from samples by accelerated solvent extraction (ASE) and then purified by fluid management systems (FMS) with silica column, alumina column and carbon column. Confirmation and quantitative analysis at pg/g level of PCDD/Fs were performed by HRGC/HRMS using voltage selective ion record (VSIR) mode. Recoveries of fifteen isotopically labeled compound solutions (LCS) and the precision and recovery standards (PAR) were found to be in the range of 49.8% -85.3% and 93.2% - 113.8%, respectively. The detection limits of the method for both 2, 3, 7, 8-tetrachloro-dibenzo-furan (TCDF) and 2, 3, 7, 8-tetrachloro-dibenzo-p-dioxin (TCDD) were determined to be 0.1 pg/g. This method not only meets the requirements of international standards, but also shortens analysis time from 2 weeks to 2 days.

Topics: Benzofurans; Chromatography, Gas; Dibenzofurans, Polychlorinated; Dioxins; Furans; Limit of Detection; Mass Spectrometry; Plant Oils; Polychlorinated Dibenzodioxins

Topics: Animals; Benzofurans; Bivalvia; China; Chromatography, Gas; Dioxins; Environmental Monitoring; Fresh Water; Pesticide Residues; Water Pollutants, Chemical

We examined the metabolism of dibenzofuran (DF) and dibenzo-p-dioxin (DD) by the biphenyl dioxygenase (BPDO) of Comamonas testosteroni B-356 and compared it with that of Burkholderia xenovorans LB400. Data showed that both enzymes oxygenated DF at a low rate, but Escherichia coli cells expressing LB400 BPDO degraded DF at higher rate (30 nmol in 18 h) compared with cells expressing B-356 BPDO (2 nmol in 18 h). Furthermore, both BPDOs produced dihydro-dihydroxy-dibenzofuran as a major metabolite, which resulted from the lateral oxygenation of DF. 2,2',3-Trihydroxybiphenyl (resulting from angular oxygenation of DF) was a minor metabolite produced by both enzymes. Deuterated DF was used to demonstrate the production of 2,2',3-dihydroxybiphenyl through angular oxygenation of DF. When tested for their ability to oxygenate DD, both enzymes produced as sole metabolite, 2,2',3-trihydroxybiphenyl ether at about the same rate, indicating similar catalytic properties toward this substrate. Altogether, although LB400 and B-356 BPDOs oxygenate a different range of chlorobiphenyls, their metabolite profiles toward DF and DD are similar. This suggests that co-planarity influences the regiospecificity of BPDO toward DF and DD to a higher extent than the presence of an ortho substituent on the molecule.

Topics: Benzofurans; Biodegradation, Environmental; Biphenyl Compounds; Burkholderia; Comamonas testosteroni; Dioxins; Dioxygenases; Escherichia coli; Polychlorinated Biphenyls

Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in plastics and textile coatings, and these compounds have been recognized as ubiquitous environmental contaminants. Furthermore, it is considered a serious problem that polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs), having toxicities similar to those of chlorinated dioxins, are generated by the manufacture of brominated flame retardants (BFRs) such as PBDEs, and formed by the combustion of substances containing BFRs. Several congeners of PBDD/DFs and PBDEs have been detected in the adipose tissue of the Japanese. Although food is suspected as an exposure source, little information is available regarding the levels of these brominated compounds in food, as compared with information regarding dioxin or polychlorinated biphenyls. It is necessary to investigate the levels of these brominated organic compounds in various foods and to estimate their influence in the case of human exposure. We developed an efficient method of analyzing PBDEs and PBDD/DFs contents in food samples using accelerated solvent extraction and determined the concentrations in several marine products such as raw fish, processed foods, and seaweed purchased in Japan. A recovery test (n = 5) using the method and involving dried fish showed acceptable recoveries of 57.7-78.5% (RSD 5.4-15.9%) for PBDEs and 50.0-56.4% (RSD 1.5-7.9%) for PBDD/DFs. In the analysis of marine product samples, several congeners of PBDEs were detected in raw fish, processed fish, and seaweed; the highest concentration of sigmaPBDEs was detected in yellowtail (1161 pg/g whole basis), followed by mackerel (553.5 pg/g whole basis). The most dominant congener present in these marine samples was 2,2',4,4'-tetraBDE (#47).

Topics: Animals; Benzofurans; Dioxins; Ethers; Fishes; Polybrominated Biphenyls; Seafood; Seaweed; Shellfish

Postnatal exposure to dioxins in breastfed infants occurs mainly during breast-feeding. The exposure to a substantial amount of endocrine disruptors in the early days of life may cause long-term health effects. Test subjects were healthy and primiparous mothers with a mean age of 28 (S.D. = 3.8) in 2001. The PCDD/F congeners were analyzed in the breast milk using gas chromatograph/high resolution mass spectrometry. The mean level of PCDD/Fs was 7.4 pg-WHO-TEQ/g lipid, which is significantly lower than the level found in individuals from other countries. The total PCDD WHO-TEQ levels in breast milk had a significant positive association with maternal age and a slightly negative association with perinatal BMI (body mass index of the period before and after the delivery). The estimated daily intake of 10.5 pg-WHO-TEQ/kg/day from individual breast milk was predicted for a breastfed infant at 6 months of age with proper assumption of 8 kg body weight, 854 milk per day of consumption, 95% of dioxin absorption rate, and linear decline of dioxin during lactation. Based on the lower WHO-TEQ levels in the breast milk, breast-feeding should still be encouraged and continued in Taiwan.

Topics: Adult; Asia; Benzofurans; Breast Feeding; Dioxins; Environmental Exposure; Europe; Female; Food Contamination; Health Surveys; Humans; Infant; Infant Formula; Maximum Allowable Concentration; Milk, Human; Parity; Taiwan; World Health Organization

To analyse the levels of polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in sea fish samples in some sea area in China surveyed by using isotope dilution HRGC/HRMS and was evaluated the local people with PCDD/Fs exposure from eating fish.. Seven different kinds of fish and twenty fishes were sampled totally. Dibenzo-p-dioxins and dibenzo-furans were extracted from fish samples by Soxhlet extraction, concentrated and purified by FMS column chromatograph and enriched by carbon column. Confirmation and quantitative analysis at ng/kg level of PCDD/Fs was performed by HRGC/HRMS using multiple ion detection mode (MID).. Carp-2 was the certified reference material obtained from the NRC Institute of Canada. The concentration of 9 compounds was consistent with the certified value, and precision was evaluated in this study. The relative standard deviation was less than 15 percent for three times determination. The average concentration of 20 sea fishes was 1.48 ng/kg wet weight, the range was in 0.21-8.10 ng/kg wet weight, and the average total toxicity equivalency factor (TEQ) was 0.292 ng TEQ/kg (wet weight basis) and the range was 0.030-1.291 ng TEQ/kg for these 20 fishes. The evaluation exposure from fish for local people was 0.58 pg WHO-TEQ/kg BW.day.. The levels of PCDD/Fs was different from sample to sample, and the exposure from fish be less than WHO tolerance limit standard, however, the status for PCDD/Fs pollution should not be ignored especially when having an intake of multi-food.

Topics: Animals; Benzofurans; China; Dioxins; Environmental Pollutants; Fishes; Polychlorinated Biphenyls; Seafood

Adipose tissue samples from 158 cattle raised locally at experiment stations across the USA were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). While 80% of the samples had PCDD/F concentrations that fell within the range of a previous US survey of beef animals (not detected -4.1 ppt toxic equivalency), several animals had exceptionally high concentrations (8-54 ppt toxic equivalency). The investigations of three facilities where highly contaminated animals were raised found pentachlorophenol-treated wood at each site. The congener pattern in the animals' tissues and the lack of elevated PCDD/F levels in other environmental samples, i.e. hay and soil, indicated that the treated wood was the source of contamination. A congener pattern similar to that of pentachlorophenol-exposed animals was seen for the means and medians of the entire data, i.e. OCDD, HpCDD and 1,2,3,6,7,8-HxCDD dominated, the PCDD concentrations equalled or exceeded the furan concentrations, and the concentration of 1,2,3,6,7,8-HxCDD was six times that of the other HxCDD isomers. This suggested that pentachlorophenol-treated wood contributed measurably to many of the animals in this survey. The largest contributors to the median toxic equivalencies were 1,2,3,7,8-PeCDD (40%) and 1,2,3,6,7,8-HxCDD (16%). No clear geographical trends emerged from the data.

Topics: Adipose Tissue; Animal Husbandry; Animals; Benzofurans; Cattle; Dioxins; Environmental Pollutants; Female; Food Contamination; Male; Meat; Pentachlorophenol; United States; Wood

The concentrations and profiles of dibenzo-p-dioxins, dibenzofurans, polychlorinated biphenyls and polynuclear aromatic compounds in various environmental matrices are presented in this study. The examined environmental matrices are total suspended particles, fly ash and soil collected in NW Greece, an area characterized by intensive coal burning for electrical power generation. Moreover, the occurrence of organic micropollutants in soot after an accidental fire was examined and the possible impact on the outdoor environment was evaluated. Results were statistically treated to obtain information on representative PCDD/F profiles in each matrix and to compare these profiles with the compositional patterns of possible sources from literature. Coal combustion, fly ash and vehicle exhausts appeared to be the most possible sources in local atmosphere.

Topics: Benzofurans; Carbon; Coal; Dioxins; Environmental Pollutants; Gas Chromatography-Mass Spectrometry; Greece; Polychlorinated Biphenyls; Polycyclic Aromatic Hydrocarbons; Principal Component Analysis; Soil; Vehicle Emissions

This study determined PCDD/F and PCB levels in human milk, examined factors associated with levels of contamination, and assessed the infant body burden from breast-feeding. The congeners of PCDD/Fs, dioxin-like PCBs, and indicator PCBs were analyzed by HRGC/HRMS for 36 human milk samples from healthy women, aged 20-35 years, from December 2000 to November 2001 in central Taiwan. Mean levels of WHO-TEQs in human milk were 10.5 (95% CI=8.8-12.2) and 14.5 (95% CI=12.5-16.5) pg-TEQ/g lipid for those <29 and > or =29 years old, respectively. PCB 138 concentration significantly predicted total WHO-TEQs with r2=0.84 (p <0.001). Milk level of dioxin-TEQ was 9.63 pg-TEQ/g lipid (95% CI=7.0-13.2) in those with a yearly income $29,000 compared to 6.3 pg-TEQ/g lipid (95% CI=5.2-7.6) for those whose yearly income was $18,000 per year. Women who reported being Buddhist (64.3 ng/glipid) had significantly higher indicator PCB concentrations than did those who reported being Taoist (35.3 ng/g lipid). The monthly dioxin intake of exclusively breastfed infants decreased with increasing duration of lactation. The cumulative dose of exclusively breastfed infants (76.5 ng TEQ, 95% CI=69.7-83.3) was significantly greater compared to that of formula-fed infants (CI=16.4-17.0) at one year and to that of infants at birth (3.90 ng TEQ, 95% CI=3.6-4.2). Our findings suggest that breast-feeding should be strongly encouraged for infants in Taiwan.

Topics: Adult; Age Factors; Benzofurans; Biphenyl Compounds; Body Burden; Breast Feeding; Diet; Dioxins; Education; Environmental Pollutants; Female; Humans; Income; Infant; Infant Food; Infant, Newborn; Milk, Human; Polychlorinated Biphenyls; Religion; Socioeconomic Factors

Three different extraction methods were evaluated: Soxhlet extraction, accelerated solvent extractor extraction and alkali digestion with high-resolution gas chromatography/high-resolution mass spectrometry, for the analysis of edible freshwater fish and frogs. The recovery efficiencies for the different extraction methods were also compared. Using these extraction methods, the concentrations and spatial distributions of these compounds in freshwater fish and frogs (n = 99), collected from 31 locations on four major river systems (Han, Nakdong, Kum and Youngsan) and two wetlands in South Korea, were examined. The concentrations of total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in all the freshwater fish and frog samples were analysed. The toxic equivalency (TEQ) concentration of PCDD/Fs in fish ranged from 0 (n.d.) to 1.309 pg I-TEQ g(-1) wet weight. Detailed concentrations for different types of fish were as follows (pg I-TEQ g(-1) wet weight): 0 (n.d.)-1.309 for crucian (mean 0.331, n = 28), 0.004-0.743 for carp (0.244, n = 10), 0.004-0.592 for dace (0.198, n = 8), 0.187-0.400 for cornet fish (0.287, n = 3), 0.164-0.410 for Korean piscivorous chub (0.303, n = 6), 0.105-0.516 for bass (0.310, n = 2), 0.451-0.812 for mullet (0.631, n = 2), 0.082 for long-nosed barbell, 0.100 for common Korean bitterling and 0.995 for dark chub. The total TEQ concentration ranged from 0 (n.d.) to 1.258 pg I-TEQ g(-1) wet weight for the two kinds of frogs (n = 36) investigated: 0 (n.d.)-1.258 pg I-TEQ g(-1) (mean 0.346, n = 29) for the bullfrog and from 0 (n.d.)-0.474 pg I-TEQ g(-1) (0.185, n = 7) for the mountain frog.

Topics: Animals; Bass; Benzofurans; Carps; Dioxins; Fishes; Food Contamination; Fresh Water; Gas Chromatography-Mass Spectrometry; Goldfish; Korea; Rana catesbeiana; Ranidae

The dioxin-degrading strain Pseudomonas veronii PH-03 was isolated from contaminated soil by selective enrichment techniques. Strain PH-03 grew on dibenzo-p-dioxin and dibenzofuran as a sole carbon source. Further, 1-chlorodibenzo-p-dioxin, 2-chlorodibenzo-p-dioxin and other dioxin metabolites, salicylic acid, and catechol were also metabolized well. Resting cells of strain PH-03 transformed dibenzo-p-dioxin, dibenzofuran, 2,2',3-trihydroxybiphenyl, and some chlorodioxins to their corresponding metabolic intermediates such as catechol, salicylic acid, 2-hydroxy-(2-hydroxyphenoxy)-6-oxo-2,4-hexadienoic acid, and chlorocatechols. The formation of these metabolites was confirmed by comparison of gas chromatography-mass spectrometry (GC-MS) data with those of authentic compounds. Although we did observe the production of 3,4,5,6-tetrachlorocatechol (3,4,5,6-TECC) from 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD) with resting cell suspensions of PH-03, growth of strain PH-03 in the presence of 1,2,3,4-TCDD was poor. This result suggests that strain PH-03 is unable to utilize 3,4,5,6-TECC, even at very low concentration (0.01 mM) due to its toxicity. In cell-free extracts of DF-grown cells, 2,2',3-trihydroxybiphenyl dioxygenase, 2-hydroxy-6-oxo-6-phenyl-2,4-hexadienoic acid hydrolase, and catechol-2,3-dioxygense activities were detected. Moreover, the activities of meta-pyrocatechase and 2,2',3-trihydroxybiphenyl dioxygenase from the crude cell-free extracts were inhibited by 3-chlorocatechol. However, no inhibition was observed in intact cells when 3-chlorocatechol was formed as intermediate.

Topics: Benzofurans; Biodegradation, Environmental; Biotransformation; Catechols; Dioxins; Kinetics; Oxygen Consumption; Pseudomonas

An extended study of seven fused silica capillary gas chromatographic (GC) columns has been conducted with regard to separation of international toxic equivalent factor (I-TEF) isomers (tetra- through octa-chlorinated at 2,3,7,8 positions) of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) from closely co-eluted other isomers using high-resolution gas chromatography-high-resolution mass spectrometry (HRGC-HRMS). The data are explicated in mass chromatograms of Series 5 GC columns from a variety of manufacturers (Varian CP-Sil 8 CB LowBleed/MS, Phenomenex ZB-5UMS, Agilent HP-5MS, Restek Rtx-5MS, Supelco Equity-5, J&W Scientific DB-5 and DB-5MS), according to relative retention times, and 2,3,7,8-substituted isomer concentrations for each of the columns tested. Results showed differences between 5% phenyl methyl silicone and 5% silphenylene (Si-arylene) silicone polymer type GC stationary phases in separation of 2,3,7,8-substituted PCDDs/PCDFs from closely co-eluted isomers. The separation differences for Si-arylene type columns resulted in lower toxic equivalence (TEQ) values compared to the siloxane-based columns. Because of differences in product nomenclature and manufacturing practices by various manufacturers, incorrect assumptions and comparisons may be made regarding the interchangeability of these columns for PCCD/PCDF separations. The data presented are the most comprehensive to date and provide a valuable addition to operational criteria for the standard US Environmental Protection Agency methods 1613b and 8290.

Topics: Benzofurans; Chromatography, Gas; Dioxins; Mass Spectrometry; Sensitivity and Specificity

Dibenzofuran (DF) is formed from phenol and benzene in combustion gas exhaust streams prior to particle collection equipment. Subsequent chlorination at lower temperatures on particle surfaces is a potential source of chlorinated dibenzofuran (CDF). Gas streams containing 8% O(2) and approximately 0.1% DF vapor were passed through particle beds containing copper (II) chloride (0.5% Cu, mass) at temperatures ranging from 200 to 400 degrees C to investigate the potential for CDF formation during particle collection. Experiment duration was sufficient to provide an excess amount of DF (DF/Cu=3). The efficiency of DF chlorination by CuCl(2) and the distribution of CDF products were measured, with effects of temperature, gas velocity, and experiment duration assessed. Results of a more limited investigation of dibenzo-p-dioxin (DD) chlorination by CuCl(2) to form chlorinated DD (CDD) products are also presented. The efficiency of DF/DD chlorination by CuCl(2) was high, both in terms of CuCl(2) utilization and DF/DD conversion. Total yields of Cl on CDF/CDD products of up to 0.5 mole Cl per mole CuCl(2) were observed between 200 and 300 degrees C; this suggests that nearly 100% CuCl(2) was utilized, assuming a conversion of two moles of CuCl(2) to CuCl per mole Cl added to DD/DF. In a short duration experiment (DF/Cu=0.3), nearly 100% DF adsorption and conversion to CDF was achieved. The degree of CDF chlorination was strongly dependent on gas velocity. At high gas velocity, corresponding to a gas-particle contact time of 0.3 s, mono-CDF (MCDF) yield was largest, with yields decreasing with increasing CDF chlorination. At low gas velocity, corresponding to a gas-particle contact time of 5 s, octa-CDF yield was largest. DF/DD chlorination was strongly favored at lateral sites, with the predominant CDF/CDD isomers within each homologue group those containing Cl substituents at only the 2,3,7,8 positions. At the higher temperatures and lower gas velocities studied, however, broader isomer distributions, particularly of the less CDD/CDF products, were observed, likely due to preferential destruction of the 2,3,7,8 congeners.

Topics: Air Movements; Benzene; Benzofurans; Copper; Dioxins; Incineration; Phenol; Refuse Disposal; Temperature

Bioremediation is a low-cost treatment alternative for the cleanup of polychlorinated-dioxin-contaminated soils and fly ash when pollution spread is wide-ranging. An interesting fungus, Ceriporia sp. MZ-340, with a high ability to degrade dioxin, was isolated from white rotten wood of a broadleaf tree from Kyushu Island in Japan. We have attempted to use the fungus for bioremediation of polychlorinated-dioxin-contaminated soil on site. However, we have to consider that this trial has the potential problem of introducing a biohazard to a natural ecosystem if this organism is naturalized. We have therefore developed a monitoring system for the introduced fungus as a part of the examination and evaluation of bioremediation in our laboratory. We have also developed a PCR-based assay to reliably detect the fungus at the bioremediation site. DNA isolated from the site was amplified by PCR using a specific primer derived from internal transcribed spacer region (ITS: ITS1, 5.8S rDNA and ITS2) sequences of Ceriporia sp. MZ-340. We successfully monitored Ceriporia sp. MZ-340 down to 100 fg/ micro l DNA and down to 2 mg/g mycelium. We also successfully monitored the fungus specifically at the bioremediation site. The polychlorinated dibenzo- p-dioxin and polychlorinated dibenzofuran content was observed to decrease in response to treatment with the fungus. The species-specific PCR technique developed in the present work is useful in evaluating the possibility of on-site bioremediation using the fungus Ceriporia sp. MZ-340.

Topics: Air Pollutants; Benzofurans; Biodegradation, Environmental; Carbon; Coal Ash; Dioxins; DNA, Fungal; DNA, Ribosomal Spacer; Particulate Matter; Polymerase Chain Reaction; Polyporales; Sensitivity and Specificity

Marine bacterial strains (BP-PH, CAR-SF, and DBF-MAK) were isolated using biphenyl, carbazole (CAR), or dibenzofuran (DF) respectively as substrates for growth. Their 16S ribosomal DNA sequences showed that the species closest to strain BP-PH, strain CAR-SF, and strain DBF-MAK are Alteromonas macleodii (96.3% identity), Neptunomonas naphthovorans (93.1% identity), and Cycloclasticus pugetii (97.3% identity), respectively. The metabolites produced suggested that strain CAR-SF degrades CAR via dioxygenation in the angular position and by the meta-cleavage pathway, and that strain DBF-MAK degrades DF via both lateral and angular dioxygenation. Polychlorinated biphenyl (KC-300) and 2,3-dichlorodibenzo-p-dioxin were partially degraded by strain BP-PH and strain DBF-MAK, while 2,7-dichlorodibenzo-p-dioxin and 2,4,8-trichlorodibenzofuran remained virtually unchanged.

Topics: Bacteria; Benzofurans; Biodegradation, Environmental; Biphenyl Compounds; Carbazoles; Culture Media; Dioxins; Molecular Sequence Data; Phylogeny; Polychlorinated Dibenzodioxins; Seawater; Water Microbiology

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were extracted by accelerated solvent extraction from animal feed samples and analysed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). In all of the feed samples analysed, the concentrations of PCDD/Fs and PCBs were below the existing tolerance limit of 5 pg I-TEQ g(-1) and 200 ng g(-1) fat, respectively. The mean concentrations of the total PCDDs, total PCDFs and total PCBs were 1.73-11.50 pg g(-1), 0.23-11.91 pg g(-1) and 60.00-234.40 pg g(-1) feed, respectively. Investigation of the correlations among the concentrations of PCDDs, PCDFs and PCBs showed that samples containing increased amounts of PCDFs also contained higher concentrations of PCDDs, with an average ratio of PCDF:PCDD of about 1.23:1 (r(2)=0.72, p<0.05). The correlation between the concentrations of PCDD/Fs and PCBs was positive but not significant.

Topics: Animal Feed; Animals; Benzofurans; Biphenyl Compounds; Cattle; Dioxins; Food Contamination; Fungicides, Industrial; Gas Chromatography-Mass Spectrometry; Korea; Poultry; Swine

In the present study, a dialytic method that uses a DNA aqueous solution to remove and enrich dioxins from polluted water was proposed. Circular dichroism (CD) and fluorescent spectra indicated that dibenzo-p-dioxin (DD), dibenzofuran (DF) and biphenyl (BP), which are dioxin derivatives, form complexes with DNA. Their experimental dialytic sorption coefficients were measured by quantifying the concentrations of DD, DF, and BP in aqueous solutions before and after dialysis of the DNA solution, and the values were 2.1x10(5), 1.3x10(5), and 1.5x10(7), respectively. As a simulated water treatment model, DNA solution was dialyzed in an aqueous mixture of DD, DF, and BP for 96h, the HPLC studies showed that the dioxin derivatives have been concentrated in the DNA solution about 200 times. The dialyzed DNA solution was reusable by an extraction with hexane.

Topics: Benzofurans; Biphenyl Compounds; Circular Dichroism; Dialysis; Dioxins; DNA; Metals; Molecular Structure; Solutions; Spectrometry, Fluorescence

A clean-up method for polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs) and diphenyl ethers (PBDEs) was modified using combinations of multi-layered silica gel, Florisil and active carbon columns. By using active carbon column chromatography in the final procedure, PBDEs were well separated from PBDD/Fs in an elution test with reference standards. We report the application of this method to sediment samples taken from industrialized areas in Japan. These sediments contained PBDEs ranging in concentration from 13 to 2394 pg/g, dry wt. PBDEs did not interfere with the quantification of PBDD/Fs. In addition, PBDEs found in the PBDD/F fraction did not interfere with the identification of PBDFs using the HRGC/HRMS separation method. Some 2,3,7,8-tetra- to hexabrominated dioxins and furans were also detected in the sediment samples.

Topics: Benzofurans; Carbon; Carbon Isotopes; Chromatography; Dioxins; Environmental Pollution; Geologic Sediments; Phenyl Ethers; Polybrominated Biphenyls; Reference Standards

In 2000, as part of a survey programme, the German authorities detected high levels of dioxins in a choline chloride (CC) premix used as animal food component. The contaminated additive consisted of different products of mineral and vegetable origin acting as a carrier. The CC was manufactured in Belgium. The final product was produced in and distributed from a plant in Spain. The German authorities informed all European Community members of the incident. The Spanish Ministry of Agriculture, Fisheries and Food and the Regional Authorities immediately conducted a survey in collaboration with the Spanish Council for Scientific Research (CSIC) to determine and isolate the source of the contamination. Analysis of a large number of samples of pure CC, pine sawdust, almond shell and other substances currently used in the preparation of the premix confirmed the presence of a significant amount of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans in mixtures in which pine sawdust was present. An analysis of the congener profiles revealed similarities with those found in technical pentachlorophenol (PCP) formulations. The conclusion was that PCP-contaminated sawdust as carrier for CC was source of dioxin contamination in feedingstuff.

Topics: Animal Feed; Benzofurans; Choline; Dibenzofurans, Polychlorinated; Dioxins; Food Contamination; Gas Chromatography-Mass Spectrometry; Isomerism; Pentachlorophenol; Polychlorinated Biphenyls

While polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) and the corresponding polybrominated congeners must be considered as animal teratogens and carcinogens, little information is available on corresponding polyfluorinated compounds (PFDD/PFDF). Kinetic studies on a few fluorinated dibenzo-p-dioxins and dibenzofurans revealed a rapid elimination, suggesting a much lower toxicity than the corresponding polychlorinated and polybrominated congeners. In order to obtain further clues on the possible toxicity, the kinetics and organ distribution (in liver, thymus and adipose tissue) of a PFDD/PFDF-mixture were studied in Wistar rats after intravenous application. The congeners investigated included four of the 2,3,7,8-substituted, and four of the not-2,3,7,8-substituted dibenzo-p-dioxins, as well as two dibenzofurans. The main result of our studies is the finding that the concentration in the thymus of several of the 2,3,7,8-substituted PFDD/PFDF greatly exceeded that in hepatic tissue. An organotropy quite different from that of the other polyhalogenated congeners must be expected, immunosuppressive effects presumably being the predominant ones. Overall, the elimination half-life of all the PFDD/PFDF studied is considerably shorter than that of the corresponding polychlorinated or polybrominated congeners, in the rat, suggesting a much lower toxicity in this species. No information is available for other species, e.g. nonhuman primates or humans.

Topics: Animals; Benzofurans; Dioxins; Female; Half-Life; Injections, Intravenous; Liver; Rats; Rats, Wistar; Thymus Gland; Tissue Distribution

A model of the absorption and desorption of persistent lipophilic organic pollutants in the human gastrointestinal tract was formulated. The influence of the dietary intake of chemical, the chemical concentration in human tissue, the physical-chemical properties of the chemical, and the sorption properties of the feces on the predicted net mass transfer of chemical was explored and shown to be consistent with experimental observations. The model was parametrized and tested using a data set of approximately 800 measurements of net absorption/excretion of polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans that were obtained in experiments with 14 human volunteers. Overall good agreement was obtained between the predicted and measured values. The largest discrepancies were observed in cases of net excretion because the model was not able to account for the considerable individual and temporal variability in the sorption properties of the feces. In a sample model application, good agreement was found between concentrations of octachlorodibenzo-p-dioxin in blood measured in different age groups of the background population and values predicted by the model.

Topics: Absorption; Benzofurans; Diet; Digestive System; Dioxins; Environmental Pollutants; Feces; Humans; Models, Theoretical; Polychlorinated Biphenyls

Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), persistent pollutants that accumulate in the food chain, pose a risk to humans through consumption of tainted livestock. Clenbuterol, a leanness-enhancing agent, was tested for usefulness in PCDD/F body store reduction through body fat reduction (the predominant site of accumulation). To mimic the situation of contaminated animals, rats were given feed with or without a mixture of PCDD/F (0.6 to 2.7 ng/congener per day) for 10 d, followed by 16 d of feed with or without dietary clenbuterol (2 mg/kg feed). Clenbuterol reduced body fat by 28% (P < 0.05), increased muscle mass by 25% (P < 0.02), and decreased liver mass by 7% (P < 0.02). Although the concentrations of most PCDD/F per gram of fat were slightly increased after clenbuterol treatment, the total amount of PCDD/F that remained in fat was reduced by approximately 30%. Muscle PCDD/F concentrations and total burden were decreased by clenbuterol. In contrast, clenbuterol tended to increase concentration, but not total burden of PCDD/F in livers. One congener known to be rapidly metabolized and excreted, 2,3,7,8-TCDF, was the exception to this increase, decreasing 40% with clenbuterol treatment. This was also the congener that showed the greatest reduction in both fat and muscle. Examination of the ratio of PCDD/F in liver and fat revealed that clenbuterol increased the liver's share of the body burden of PCDD/F, from 38 to 75%. In a remediation/disposal context, these findings would be beneficial if clenbuterol lowered the meat and carcass burden of PCDD/F to safe levels, requiring only livers to be disposed of as hazardous waste.

Topics: Adipose Tissue; Animals; Benzofurans; Body Burden; Clenbuterol; Dibenzofurans, Polychlorinated; Dioxins; Food Contamination; Liver; Male; Muscle, Skeletal; Random Allocation; Rats; Rats, Sprague-Dawley; Soil Pollutants; Tissue Distribution

Hydroxylation of dibenzo- p-dioxin (DD), dibenzofuran (DF), biphenyl (BP) and diphenyl ether (DPE) by the white-rot fungus Phlebia lindtneri GB-1027 was studied. DD and DF were rapidly degraded in a culture of P. lindtneri. The initial oxidation products were identified by gas chromatography-mass spectrometry. P. lindtneri oxidized DD to 2-hydroxy-DD, and DF to 2- and 3-hydroxy-DF. BP and DPE were also oxidized to p-hydroxy-BP and p-hydroxy-DPE, respectively. The oxidation catalyzed by P. lindtneri with each substrate was position-specific, because the hydroxyl group was introduced to the molecular edge of every substrate. Significant inhibition of the degradation of DD and DF was observed in incubation with the cytochrome P-450 monooxygenase inhibitors 1-aminobenzotriazole and piperonyl butoxide. These experiments with cytochrome P-450 inhibitors, and formation of the mono-hydroxyl metabolites suggest that P. lindtneri initially oxidizes DD, DF, BP, and DPE by a cytochrome P-450 monooxygenase and that it directly introduces a hydroxyl group to each of these substrates.

Topics: Basidiomycota; Benzofurans; Biodegradation, Environmental; Biphenyl Compounds; Cytochrome P-450 Enzyme System; Dioxins; Hydroxylation; Kinetics; Mass Spectrometry; Oxidation-Reduction; Oxygenases; Phenyl Ethers

The actions of a white-rot fungus on two chlorinated aromatic compounds, known to be persistent environmental contaminants, were studied. Two models, both-ring chlorinated dioxin, 2,7-dichlorodibenzo-p-dioxin (2,7-diCDD) and 2,8-dichlorodibenzofuran (2,8-diCDF), were metabolized by the white-rot fungus Phlebia lindtneri. 2,7-DiCDD disappeared linearly in the culture of P. lindtneri; over a 20-day incubation period, with only 45% remaining in the culture. One of the metabolites produced by P. lindtneri from a 5-day incubated culture with 2,7-diCDD or 2,8-diCDF was identified by gas chromatography-mass spectrometry. P. lindtneri was shown to metabolize 2,7-diCDD and 2,8-diCDF to hydroxy-diCDD and hydroxy-diCDF, respectively.

Topics: Basidiomycota; Benzofurans; Biodegradation, Environmental; Chromatography, Gas; Dioxins; Environmental Pollutants; Hydroxylation; Mass Spectrometry; Oxidation-Reduction; Polychlorinated Dibenzodioxins

Two bacterial strains capable of utilizing dibenzofuran (DF) as a sole carbon source were isolated from soil samples of reclaimed land. The strains designated HL1 and HL7 were identified as Klebsiella sp. and Sphingomonas sp., respectively, on the basis of biochemical characteristics and the sequences of the 16S ribosomal DNA. Sphingomonas sp. strain HL7 degraded non-, mono- and also dichlorinated DF and dibenzo-p-dioxin (DD). Klebsiella sp. strain HL1 was able to degrade non- and monochlorinated DFs and DDs, but not dichlorinated ones. The metabolites formed from DF by strains HL1 and HL7 were similar to those by dioxin-degrading bacteria Sphingomonas sp. strain RW1 except for salicylic acid and catechol. Strain HL7 had a gene homologous to that encoding the dioxin dioxygenase alpha-subunit (dxnA1) gene of Sphingomonas sp. strain RW1. However, Southern hybridization analysis showed that the size of an EcoRV-digested genomic fragment involving the dioxin dioxygenase gene of strain HL7 was smaller than that of strain RW1, and that strain HL1 did not have the homologous gene. Strains HL1 and HL7 provided useful information regarding the dioxygenase genes.

Topics: Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Klebsiella; Oxygenases; Phylogeny; Soil Microbiology; Sphingomonas

Biphenyl dioxygenase (Bph Dox) is responsible for the initial dioxygenation of biphenyl. The large subunit (BphA1) of Bph Dox plays a crucial role in determination of substrate specificity of biphenyl-related compounds including polychlorinated biphenyls (PCBs). Functional evolution of Bph Dox of Pseudomonas pseudoalcaligenes KF707 was accomplished by random priming recombination of the bphA1 gene, involving two rounds of in vitro recombination and mutation followed by selection for increased activity in vivo. Evolved Bph Dox acquired novel and multifunctional degradation capabilities not only for PCBs but also for dibenzofuran, dibenzo-p-dioxin, dibenzothiophene, and fluorene, the compounds scarcely attacked by the original KF707 Bph Dox. The modes of oxygenation were angular and lateral dioxygenation for dibenzofuran and dibenzo-p-dioxin, sulfoxidation for dibenzothiophene, and mono-oxygenation for fluorene. These enzymes also exhibited enhanced degradation abilities for PCB congeners, retaining 2,3-dioxygenase activity and gaining 3,4-dioxygenase activity, depending on the chlorine substitution of PCB congeners. Further mutation analysis revealed that the amino acid at position 376 in BphA1 is significantly involved in the acquisition of multifunctional oxygenase activities and mode of oxygenation.

Topics: Base Sequence; Benzofurans; Cloning, Molecular; Dioxins; DNA Primers; Fluorenes; Gas Chromatography-Mass Spectrometry; Mutagenesis, Site-Directed; Oxygenases; Polychlorinated Biphenyls; Pseudomonas; Recombination, Genetic; Thiophenes

The attack by the bph-encoded biphenyl dioxygenase of Burkholderia sp. strain LB400 on a number of symmetrical ortho-substituted biphenyls or quasi ortho-substituted biphenyl analogues has been investigated. 2,2'-Difluoro-, 2,2'-dibromo-, 2,2'-dinitro-, and 2,2'-dihydroxybiphenyl were accepted as substrates. Dioxygenation of all of these compounds showed a strong preference for the semisubstituted pair of vicinal ortho and meta carbons, leading to the formation of 2'-substituted 2,3-dihydroxybiphenyls by subsequent elimination of HX (X = F, Br, NO(2), or OH). All of these products were further metabolized by 2,3-dihydroxybiphenyl 1,2-dioxygenases of Burkholderia sp. strain LB400 or of Rhodococcus globerulus P6. Dibenzofuran and dibenzodioxin, which may be regarded as analogues of doubly ortho-substituted biphenyls or diphenylethers, respectively, were attacked at the "quasi ortho" carbon (the angular position 4a) and its neighbor. This shows that an aromatic ring-hydroxylating dioxygenase of class IIB is able to attack angular carbons. The catechols formed, 2,3,2'-trihydroxybiphenyl and 2,3,2'-trihydroxydiphenylether, were further metabolized by 2,3-dihydroxybiphenyl 1,2-dioxygenase. While angular attack by the biphenyl dioxygenase was the main route of dibenzodioxin oxidation, lateral dioxygenation leading to dihydrodiols was the major reaction with dibenzofuran. These results indicate that this enzyme is capable of hydroxylating ortho or angular carbons carrying a variety of substituents which exert electron-withdrawing inductive effects. They also support the view that the conversions of phenols into catechols by ring-hydroxylating dioxygenases, such as the transformation of 2,2'-dihydroxybiphenyl into 2,3,2'-trihydroxybiphenyl, are the results of di- rather than of monooxygenations. Lateral dioxygenation of dibenzofuran and subsequent dehydrogenation and extradiol dioxygenation by a number of biphenyl-degrading strains yielded intensely colored dead-end products. Thus, dibenzofuran can be a useful chromogenic indicator for the activity of the first three enzymes of biphenyl catabolic pathways.

Topics: Benzofurans; Biodegradation, Environmental; Biphenyl Compounds; Burkholderia; Dioxins; Dioxygenases; Escherichia coli; Iron-Sulfur Proteins; Oxygenases; Polybrominated Biphenyls; Polychlorinated Biphenyls; Rhodococcus

Two kinds of bacteria having different-structured angular dioxygenases-a dibenzofuran (DF)-utilizing bacterium, Terrabacter sp. strain DBF63, and a carbazole (CAR)-utilizing bacterium, Pseudomonas sp. strain CA10-were investigated for their ability to degrade some chlorinated dibenzofurans (CDFs) and chlorinated dibenzo-p-dioxins (CDDs) (or, together, CDF/Ds) using either wild-type strains or recombinant Escherichia coli strains. First, it was shown that CAR 1,9a-dioxygenase (CARDO) catalyzed angular dioxygenation of all mono- to triCDF/Ds investigated in this study, but DF 4,4a-dioxygenase (DFDO) did not degrade 2,7-diCDD. Secondly, degradation of CDF/Ds by the sets of three enzymes (angular dioxygenase, extradiol dioxygenase, and meta-cleavage compound hydrolase) was examined, showing that these enzymes in both strains were able to convert 2-CDF to 5-chlorosalicylic acid but not other tested substrates to the corresponding chlorosalicylic acid (CSA) or chlorocatechol (CC). Finally, we tested the potential of both wild-type strains for cooxidation of CDF/Ds and demonstrated that both strains degraded 2-CDF, 2-CDD, and 2,3-diCDD to the corresponding CSA and CC. We investigated the sites for the attack of angular dioxygenases in each CDF/D congener, suggesting the possibility that the angular dioxygenation of 2-CDF, 2-CDD, 2,3-diCDD, and 1,2,3-triCDD (10 ppm each) by both DFDO and CARDO occurred mainly on the nonsubstituted aromatic nuclei.

Topics: Actinomycetales; Bacterial Proteins; Benzofurans; Biodegradation, Environmental; Chlorine; Dioxins; Dioxygenases; Escherichia coli; Gas Chromatography-Mass Spectrometry; Oxygenases; Pseudomonas

A method for bioremediation of chlorinated dibenzo-p-dioxins (CDDs) and dibenzofurans (CDFs) by a carbazole-utilizing bacterium, Pseudomonas sp. strain CA10, was developed. CA10 cells transferred to carbon- and nitrogen-free mineral medium supplemented with 1 mg carbazole (CAR)/ml grew rapidly during the first 2 days; and the cells at the end of this rapid growth period showed the highest 2,3-dichlorodibenzo-p-dioxin (2,3-Cl2DD)-degrading activity. The CA10 cells pregrown for 2 days efficiently degraded 2,3-Cl2DD in aqueous solution at either 1 ppm or 10 ppm. The effect of inoculum density on the efficiency of 2,3-Cl2DD degradation was investigated in a soil slurry microcosm [ratio of soil:water = 1:5 (w/v)]. The results showed that a single inoculation with CA10 cells at densities of 10(7) CFU/g soil and 10(9) CFU/g soil degraded 46% and 80% of 2,3-Cl2DD, respectively, during the 7-day incubation. The rate of degradation of each CDD congener, 2-ClDD, 2,3-Cl2DD, and 1,2,3-Cl3DD (1 ppm each) by strain CA10 in the soil slurry system was not significantly influenced by the coexistence of the other congeners. Using this soil slurry system, we tried an experimental bioremediation of the actual dioxin-contaminated soil, which contained mainly tetra- to octochlorinated dioxins. Although the degradation rate of total CDD and CDF congeners by a single inoculation with CA10 cells was 8.3% after a 7-day incubation, it was shown that strain CA10 had a potential to degrade tetra- to hepta-chlorinated congeners including the most toxic compound, 2,3,7,8-tetrachlorinated dibenzo-p-dioxin.

Topics: Benzofurans; Biodegradation, Environmental; Biotechnology; Carbazoles; Culture Media; Dioxins; Pseudomonas; Soil Pollutants

Previous studies have shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), and 1,2,3,4,7, 8-hexachlorodibenzo-p-dioxin (HxCDD), and their equipotent mixture block ovulation, reduce ovarian weight gain and alter preovulatory hormone levels in a similar manner. The objective of the current experiment was to investigate the effect of other structurally related compounds such as chlorinated furans and biphenyls on ovulation and related hormonal endpoints. The gonadotropin-primed immature female rat model was used to study the effect of 2,3,4,7, 8-pentachlorodibenzofuran (PeCDF), 3,3',4,4',5-pentachlorobiphenyl (PeCB), and 2,2',5,5' tetrachlorobiphenyl (TCB) and their mixture with polychlorinated dibenzo-p-dioxins (PCDDs) on ovulation. Rats were dosed on Day 23 of age at 0900 h with individual congeners (PeCDF, PeCB, TCB) or a mixture of five compounds, which included TCDD, PeCDD, HxCDD, in addition to PeCDF and PeCB. Equine choronic gonadotropin (eCG; 5 IU) was injected 24 h later to induce follicular development. Blood and ovaries were harvested, and ovarian weights determined at various times after eCG. Serum concentrations of 17beta-estradiol (E(2)), progesterone (P(4)), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were determined by radioimmunoassay. At 72 h after injection of eCG, the number of ova shed was measured by irrigating the ova from oviducts. The slopes of the dose-responses for inhibition of ovulation generated by the individual PeCDF, PeCB, and/or their mixture with PCDDs were similar. PeCDF, PeCB, and the mixture increased serum concentrations of E(2) at 72 h after eCG injection, the day of expected ovulation; in contrast, serum P(4) and FSH were decreased at that same time point. Only the high doses of TCDD, PeCDF, and PeCB blocked LH and FSH surges at 58 h after eCG. The ovarian histology revealed that the effects of PeCDF, PeCB, and the mixture were very similar to those of PCDDs, consisting of ova in large preovulatory follicles and a lack of or reduced number of corpora lutea. Parallel dose-responses of the individual congeners (PeCDF and PeCB) and their equipotent mixture with PCDDs support the toxic equivalency (TEQ) concept for the blockage of ovulation. Thus, PCDDs, PCDFs, and PeCBs appear to block ovulation by the same or a very similar mechanism of action.

Topics: Animals; Benzofurans; Dibenzofurans, Polychlorinated; Dioxins; Dose-Response Relationship, Drug; Drug Combinations; Female; Follicle Stimulating Hormone; Luteinizing Hormone; Organ Size; Ovary; Ovulation; Polychlorinated Biphenyls; Rats; Rats, Sprague-Dawley

Removal of dibenzofuran, dibenzo-p-dioxin, and 2-chlorodibenzo-p-dioxin (2-CDD) (10 ppm each) from soil microcosms to final concentrations in the parts-per-billion range was affected by the addition of Sphingomonas sp. strain RW1. Rates and extents of removal were influenced by the density of RW1 organisms. For 2-CDD, the rate of removal was dependent on the content of soil organic matter (SOM), with half-life values ranging from 5.8 h (0% SOM) to 26.3 h (5.5% SOM).

Topics: Benzofurans; Biodegradation, Environmental; Dioxins; Ecosystem; Kinetics; Pseudomonas; Soil Microbiology; Soil Pollutants

Using the 95% prediction limits of an age-related multiplicative regression model describing the datasets of blood examinations carried out on subjects suspected of having been exposed to lead and to polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/F), it was shown that the relevant curves can be used as an alternative to reference ranges describing the actual background exposure to these pollutants. The upper limit of the actual German background exposure can be estimated by the following equations: PCDD/F as International Toxicity Equivalents in the age range of 10-70 years [pg/g lipid basis] = 1.64.age0.871 and lead in the age range of 15-80 years [microgram/l] = 18.15.age0.3638.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Benzofurans; Child; Dioxins; Environmental Monitoring; Environmental Pollutants; Female; Germany; Humans; Lead; Male; Middle Aged; Models, Statistical; Reference Values

Earlier studies in our laboratory showed that hydroxylated metabolites of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) competitively inhibit thyroxine (T4) binding to transthyretin (TTR) and type I deiodinase (D1) activity. In this study, we investigated the possible inhibitory effects of hydroxylated metabolites of polyhalogenated aromatic hydrocarbons (PHAHs) on iodothyronine sulfotransferase activity. Rat liver cytosol was used as a source of sulfotransferase enzyme in an in vitro assay with 125I-labeled 3,3'-diiodothyronine (T2) as a model substrate. Increasing amounts of hydroxylated PCBs, PCDDs, or PCDFs or extracts from incubation mixtures of PHAHs and induced liver microsomes were added as potential inhibitors of T2 sulfotransferase activity. Hydroxylated metabolites of PCBs, PCDDs, and PCDFs were found to be potent inhibitors of T2 sulfotransferase activity in vitro with IC50 values in the low micromolar range (0.2-3.8 microM). The most potent inhibitor of T2 sulfotransferase activity in our experiments was the PCB metabolite 3-hydroxy-2,3',4, 4',5-pentachlorobiphenyl with an IC50 value of 0.2 microM. A hydroxyl group in the para or meta position appeared to be an important structural requirement for T2 sulfotransferase inhibition by PCB metabolites. Ortho hydroxy PCBs were much less potent, and none of the parent PHAHs was capable of inhibiting T2 sulfotransferase activity. In addition, the formation of T2 sulfotransferase-inhibiting metabolites of individual brominated diphenyl ethers and nitrofen as well as from some commercial PHAH mixtures (e.g., Bromkal, Clophen A50, and Aroclor 1254) was also demonstrated. These results indicate that hydroxylated PHAHs are potent inhibitors of thyroid hormone sulfation. Since thyroid hormone sulfation may play an important role in regulating free hormone levels in the fetus, and PCB metabolites are known to accumulate in fetal tissues after maternal exposure to PCBs, these observations may have implications for fetal thyroid hormone homeostasis and development.

Topics: Animals; Benzofurans; beta-Naphthoflavone; Biotransformation; Cytochrome P-450 Enzyme System; Diiodothyronines; Dioxins; Hydrocarbons, Halogenated; Hydroxylation; Isoenzymes; Male; Microsomes, Liver; Phenobarbital; Polychlorinated Biphenyls; Rats; Rats, Wistar; Structure-Activity Relationship; Sulfotransferases; Sulfur; Triiodothyronine

The production of magnesium is a well known source of both aliphatic and aromatic chlorinated compounds, among others the polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The aim of this study was to establish whether increased concentrations of PCDDs and PCDFs could be found in the blood of workers in a magnesium plant.. Blood plasma from 10 workers, employed at a magnesium plant for 10 to 36 years, and from a control group consisting of nine people who had no direct contact with the production were studied. Isomer specific analyses of PCDDs and PCDFs by means of high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) techniques were performed.. A significant increase was found in the concentrations of some of the congeners, mainly PCDFs, in the workers compared with the control group. Octachlorodibenzofuran (OCDF) is the congener that most strongly correlates with occupational exposure in the magnesium plant. Low concentrations of 1,2,3,4,6,8,9-heptachlorodibenzofuran were found in seven of the workers. Such isomers--that is, not 2,3,7,8-substituted--are rarely found in human samples.. Due to the long biological half lives and lipid solubility of PCDDs and PCDFs, blood analyses may serve as an index of past cumulative occupational exposure and a means of assessing a person's exposure situation.

Topics: Benzofurans; Case-Control Studies; Dioxins; Humans; Industry; Magnesium; Occupational Exposure

The present project assessed the effect of environmental contamination with polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) on hepatic microsomal ethoxyresorufin O-deethylase (EROD) activities and morphological parameters in matched double-crested cormorant (Phalacrocorax auritus) hatchlings from egg clutches chosen for chemical analysis. Double-crested cormorant eggs were collected from five colonies across Canada, with differing levels of contamination. Levels of contamination expressed in sum of 2,3,7,8-tetrachlorodibenzo-p-dioxin-toxic equivalents (TCDD-toxic equivalents or TEQ, ng/kg egg; mean +/- SEM) were: Saskatchewan, 250 +/- 50; Chain Islands, 672 +/- 73; Christy Islet, 276 +/- 14; Crofton, 131, n = 1; and Lake Ontario, 1606 +/- 118. In the hatchlings, hepatic EROD activities (pmol/min/mg protein; mean +/- SEM) were: Saskatchewan, 283 +/- 42; Chain Islands, 516 +/- 98; Christy Islet, 564 +/- 91; Crofton, 391 +/- 52; and Lake Ontario, 2250 +/- 156. Hepatic microsomal EROD activity (pmol/min/mg protein) regressed positively on TEQ (r2 = .69; p < .00005; n = 25). Yolk weight (g) regressed negatively on TEQ (r2 = .44; p = .00005). Wing length (mm) regressed negatively on PCB-169 (r2 = .28; p = .007). Monospecific antibodies raised against rat cytochrome P-450 1A1 recognized a protein in the hepatic microsomes of the double-crested cormorant, and also in those of the great blue heron (Ardea herodias), using immunoblotting. The intensity of the stained band increased with increased EROD activity, supporting the assumption that ethoxyresorufin is a suitable substrate for avian cytochrome P-450 1A1. These results validate the use of avian hepatic microsomal EROD activity as an index of cytochrome P-450 1A1 induction by environmental levels of polychlorinated aromatic hydrocarbons and as a useful screening tool to determine the extent of exposure to such chemicals. Furthermore, the induction of cytochrome P-450 1A1 observed in the cormorant indicates that the Ah receptor-mediated process, by which TCDD and related chemicals exert many of their toxicities, has been activated.

Topics: Abnormalities, Drug-Induced; Animals; Benzofurans; Birds; Body Weight; Canada; Cytochrome P-450 CYP1A1; Cytochrome P-450 Enzyme System; Dioxins; Eggs; Microsomes, Liver; Oxidoreductases; Polychlorinated Biphenyls

Isomer-specific determinations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were performed in 19 surficial sediment samples collected from the lower Passaic River and Newark Bay, New Jersey. Total PCDD and PCDF concentrations ranged from 415 to 23,300 ng/kg (dry wt) and 37 to 8400 ng/kg, respectively. OCDD and OCDF were the predominant congeners in all samples, followed by the hepta-, hexa-, tetra-, and penta-chlorinated compounds. Forty-seven percent (9/19) of the sediment samples contained no detectable levels of 2, 3, 7, 8-TCDD. The concentrations of 2, 3, 7, 8-TCDD and 2, 3, 7, 8-TCDF ranged from nondetect to 510 ng/kg (geometric mean of 5 ng/kg) and from 2.8 to 480 ng/kg (geometric mean of 13 ng/kg), respectively. The composition of PCDD/Fs in sediments was evaluated using chemometric pattern recognition techniques. Principal components analysis and complete linkage:farthest neighbor cluster analysis revealed the presence of at least five distinctive fingerprint patterns in surficial sediments collected from different locations in the Newark Bay estuary. Differences among PCDD/F patterns were attributable to the relative presence or absence of 1, 2, 3, 4, 6, 7, 8-HpCDF and the hepta-, hexa-, and octa-chlorinated congeners. To determine whether the presence of PCDD/Fs in sediments could be associated with a single source, residues in sediments were compared to those found in three soil samples and one sump sediment sample from a former 2, 4, 5-T manufacturing plant. Significant compositional differences were observed between the two data sets. Fingerprint patterns in sediments were dominated by the higher PCDD/F chlorinated congeners and contained significantly lower levels of the tetra-chlorinated congeners, particularly 2, 3, 7, 8-TCDD, than soils from the former 2, 4, 5-T plant. These differences, as well as those observed among surficial sediments from different locations, indicate that there are clearly several different sources of 2, 3, 7, 8-TCDD and other PCDD/Fs to the estuary.

Topics: Benzofurans; Cluster Analysis; Dioxins; Fresh Water; New Jersey; New York; Pattern Recognition, Automated; Seawater; Water Pollutants, Chemical

The concentration-dependent effects of several PCB, PCDD, and PCDF congeners and several commercial PCB preparations as antiestrogens were determined in the aryl hydrocarbon (Ah)-responsive MCF-7 human breast cancer cell lines. The inhibition of the 17 beta-estradiol-induced secretion of the 52-kDa protein (procathepsin D) was measured using a combination of polyacrylamide gel electrophoresis, double-staining of the protein bands with ISS ProBlue and silver stain, and quantitation by densitometric analysis. For the PCBs, the order of antiestrogenic potency was 3,3',4,4',5-pentachlorobiphenyl > 3,3',4,4',5,5'-hexachlorobiphenyl approximately 3,3',4,4'-tetrachlorobiphenyl > 2,3,3',4,4',5'-hexa, 2,3,3',4,4'- and 2,3,4,4',5-pentachlorobiphenyl > Aroclors 1221, 1232, 1248, 1254, and 1260 were inactive as antiestrogens at the highest concentrations used in this study (10(-6) M). For the PCDDs and PCDFs, the order of antiestrogenic potency was 2,3,7,8-tetrachlorodibenzo-p-dioxin > 2,3,7,8-tetrachlorodibenzofuran > 2,3,4,7,8-pentachlorodibenzofuran > 1,2,3,7,9-pentachlorodibenzofuran > 1,3,6,8-tetrachlorodibenzofuran. With few exceptions, the order of potency for all these congeners and mixtures paralleled their relative activities as agonists for other Ah receptor-mediated responses and their competitive binding affinities for the Ah receptor. The results of this study support the role for the Ah receptor in mediating the inhibition of the 17 beta-estradiol-induced secretion of the 52-kDa protein in MCF-7 cells and also points out the utility of this technique as a bioassay for this class of compounds.

Topics: Aroclors; Benzofurans; Breast Neoplasms; Densitometry; Dioxins; Electrophoresis, Polyacrylamide Gel; Estradiol; Estrogen Antagonists; Humans; Neoplasm Proteins; Polychlorinated Biphenyls; Staining and Labeling; Structure-Activity Relationship; Tumor Cells, Cultured

Topics: Benzofurans; Czechoslovakia; Dioxins; Environmental Health; Environmental Monitoring; Environmental Pollution; Forecasting; Humans; Organizational Objectives; Pesticides; Polychlorinated Biphenyls; Polycyclic Compounds; Research

A key enzyme in the degradation pathways of dibenzo-p-dioxin and dibenzofuran, namely, 2,2',3-trihydroxybiphenyl dioxygenase, which is responsible for meta cleavage of the first aromatic ring, has been genetically and biochemically analyzed. The dbfB gene of this enzyme has been cloned from a cosmid library of the dibenzo-p-dioxin- and dibenzofuran-degrading bacterium Sphingomonas sp. strain RW1 (R. M. Wittich, H. Wilkes, V. Sinnwell, W. Francke, and P. Fortnagel, Appl. Environ. Microbiol. 58:1005-1010, 1992) and sequenced. The amino acid sequence of this enzyme is typical of those of extradiol dioxygenases. This enzyme, which is extremely oxygen labile, was purified anaerobically to apparent homogeneity from an Escherichia coli strain that had been engineered to hyperexpress dbfB. Unlike most extradiol dioxygenases, which have an oligomeric quaternary structure, the 2,2',3-trihydroxybiphenyl dioxygenase is a monomeric protein. Kinetic measurements with the purified enzyme produced similar Km values for 2,2',3-trihydroxybiphenyl and 2,3-dihydroxybiphenyl, and both of these compounds exhibited strong substrate inhibition. 2,2',3-Trihydroxydiphenyl ether, catechol, 3-methylcatechol, and 4-methylcatechol were oxidized less efficiently and 3,4-dihydroxybiphenyl was oxidized considerably less efficiently.

Topics: Amino Acid Sequence; Bacteria; Base Sequence; Benzofurans; Cosmids; Dioxins; Dioxygenases; DNA, Bacterial; Electrophoresis, Polyacrylamide Gel; Genes, Bacterial; Genomic Library; Kinetics; Molecular Sequence Data; Oxygenases; Restriction Mapping; Sequence Homology, Amino Acid; Substrate Specificity

The dose-dependent effects of a single acute exposure of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), 1,2,3,7,9-PeCDF, 1,3,6,8-tetrachlorodibenzofuran (TCDF), 3,3',4,4',5-pentachlorobiphenyl (pentaCB), and 3,3,',4,4',5,5'-hexaCB on the suppression of the splenic plaque-forming cell (PFC) response to the T-cell-independent antigen trinitrophenyl-lipopolysaccharide were determined in C57BL/6 and DBA/2 mice. In addition, the induction of hepatic microsomal ethoxyresorufin O-deethylase (EROD) activity was also measured in these animals. 2,3,7,8-TCDD and 2,3,4,7,8-PeCDF were the most immunotoxic congeners in both strains of mice and with the exception of the latter congener, the ED50 values for each compound were lower in the C57BL/6 than the DBA/2 mice. 2,3,7,8-TCDD induced hepatic microsomal EROD activity in both strains of mice whereas the other congeners were considerably less active or inactive as inducers. The results of this study demonstrated that for the halogenated aromatic hydrocarbons the immunotoxic response was a more sensitive indicator of exposure than the induction of CYP1A1 activity. The rank order for the immunotoxic potencies of the chlorinated aromatic compounds used in this study was 2,3,7,8-TCDD approximately 2,3,4,7,8-PeCDF > 3,3',4,4',5-pentaCB approximately 3,3',4,4',5,5'-hexaCB > 1,2,3,7,9-PeCDF > 1,3,6,8-TCDF. The order of activity for these congeners was similar for other Ah receptor-mediated responses and these results coupled with the differential responsiveness of the C57BL/6 and DBA/2 mice confirms the role of aryl hydrocarbon (Ah) receptor in mediating the suppression of this T-cell-independent response.

Topics: Animals; Benzofurans; Cytochrome P-450 CYP1A1; Cytochrome P-450 Enzyme System; Dioxins; Enzyme Induction; Immune System; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Microsomes, Liver; Oxidoreductases; Polychlorinated Biphenyls; Spleen; T-Lymphocytes

Topics: Agriculture; Air Pollutants; Benzofurans; Dioxins; Fires; Oryza; Smoke

Staphylococcus auriculans DBF63, which can grow on dibenzofuran (DBF) or fluorene (FN) as the sole source of carbon and energy, was isolated. Salicylic acid and gentisic acid accumulated in the culture broth of this strain when DBF was supplied as a growth substrate. Also, the formation of 9-fluorenol, 9-fluorenone, 4-hydroxy-9-fluorenone, and 1-hydroxy-9-fluorenone was demonstrated, and accumulation of 1,1a-dihydroxy-1-hydro-9-fluorenone was observed when this strain grew on FN. On the basis of these results, the degradation pathways of DBF and FN were proposed. The analogous oxidation products of dibenzo-p-dioxin were obtained by incubation with DBF-grown S. auriculans DBF63 cells.

Topics: Benzofurans; Biodegradation, Environmental; Catechol 2,3-Dioxygenase; Catechols; Culture Media; Dioxins; Dioxygenases; Fluorenes; Oxidation-Reduction; Oxygenases; Soil Pollutants; Staphylococcus

Five bulked human adipose tissue samples were analyzed for individual polychlorinated biphenyl (PCB) congeners (including selected non-ortho-substituted compounds) and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). Mean sigma PCB and sigma PCDD/F (tetra-through octachlorinated homologues) concentrations were 0.75 microgram/g and 1.22 ng/g adipose tissue respectively. Both the congener patterns and levels detected were similar to those reported by laboratories in other industrialised countries. Each sample comprised of tissue taken from donors within a given locality. However, no obvious relationships were apparent between sampling area, absolute concentrations and congener pattern of PCBs and PCDD/Fs. The contribution of individual PCDD/F and non-ortho-(o), mono-o-, and di-o-substituted PCB congeners to the total calculated toxic equivalent values (sigma TEQ) was assessed for each sample. The main contributions to the sigma TEQ were the mono-o-substituted PCB congeners #118 (TEQ = 42.5 pg/g of lipid), #156 (TEQ = 24.8 pg/g) and #105 (TEQ = 20.7 pg/g), followed by 1,2,3,6,7,8-HxCDD (TEQ = 18.2 pg/g), 2,3,4,7,8-P5CDF (TEQ = 12 pg/g), 1,2,3,7,8-P5CDD (TEQ = 11.5 pg/g), and the non-o-substituted PCB congener #126 (TEQ = 11.3 pg/g). Collectively, these compounds accounted for 80% of the sigma TEQ values. Based on the TEFs proposed by Safe (1990), the overall TEQs calculated for the monitored PCBs, were twice those due to sigma PCDD/Fs.

Topics: Adipose Tissue; Adolescent; Adult; Aged; Benzofurans; Dioxins; Humans; Middle Aged; Polychlorinated Biphenyls; Wales

The potential for exposure of employees to polybrominated dibenzofurans (PBDFs) and dibenzo-p-dioxins (PBDDs) during extrusion blending of resins containing decabromodiphenyl ether was established through previous air monitoring (area samples) and biomonitoring studies. The findings presented herein are further biomonitoring results for 42 employees and immunological tests for exposed and referent employees. Among potentially exposed men, 2,3,7,8-TBDF and 2,3,7,8-TBDD concentrations in blood lipid ranged from non-detectable to 112 parts per trillion (ppt) and from non-detectable to 478 ppt respectively. Biomonitoring results correlated well with assignments in the extruder work area when adjusted for process changes and engineering improvements and provided biological half life estimates of between 1.1 and 1.9 years for 2,3,7,8-TBDF and between 2.9 and 10.8 years for 2,3,7,8-TBDD. Results for 16 measures of the immune system were examined in relation to exposure (exposed v referent group) and in relation to the biomonitoring data. Some individual trends in immunological parameters with exposure and covariates such as age and cigarette smoking were found (for example, an increase in complement C4 with increasing concentrations of PBDFs and PBDDs, increased lymphocyte subpopulation counts with cigarette smoking); however, the overall clinical assessment was that the immune system of exposed employees was not adversely impacted at these burdens of PBDFs and PBDDs.

Topics: Adult; Aging; Benzofurans; Chemical Industry; Complement C3; Complement C4; Complement System Proteins; Dioxins; Half-Life; Humans; Immunoglobulin M; Leukocyte Count; Lipids; Male; Monitoring, Physiologic; Occupational Exposure; T-Lymphocytes; Teratogens

The Computer-Automated Structure Evaluation (CASE) Program, an expert system that automatically selects relevant descriptors for structure-activity relationships, has been used to analyze the binding of various ligands to the tetrachloro-dibenzo-p-dioxin (TCDD) receptor or Ah receptor. Two databases were analyzed. One database contained 136 polycyclic aromatic hydrocarbons (PAH), substituted dibenzo-p-dioxins, dibenzofurans and biphenyls whose binding affinities were measured by a sucrose density gradient technique. The other 87 compound database contained PAH, nitro-PAH, halo-PAH and N-heterocycles. Their binding affinities were measured by the electrofocusing assay. Within each training set significant correlations between the affinity for the TCDD receptor and relevant molecular fragments identified by the CASE program were observed. Among the halogenated aromatic hydrocarbons, fragments containing lateral halogens and a longitudinal hydrogen appeared important for TCDD receptor binding. The fragments of PAH and heterocyclic compounds that were most activating with respect to TCDD receptor binding were found to contain the classical 'bay' region and were in fact identical to the fragments found previously to be related to carcinogenicity. It was found that the activating fragments from PAH and heterocyclic compounds were different from those found within the halogenated compounds such as dibenzo-p-dioxins, dibenzofurans and biphenyls. One interpretation of the data is that two different recognition sites may be involved in Ah receptor binding.

Topics: Artificial Intelligence; Benzofurans; Biphenyl Compounds; Databases, Bibliographic; Dioxins; Heterocyclic Compounds; Ligands; Polycyclic Compounds; Receptors, Aryl Hydrocarbon; Receptors, Drug

A high-performance liquid chromatographic cleanup procedure employing normal-phase alumina and carbon--silica separations was developed for isolating polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) from other polychlorinated pollutants present in fish tissue. The method utilizes a column-switching step where the dioxins and furans are trace enriched onto a carbon-silica column as they are eluted from the alumina column. Interfering components such as polychlorinated biphenyls and chlorinated diphenyl ethers elute through the carbon--silica column. The PCDDs and PCDFs are subsequently recovered by backflushing the carbon--silica column using toluene.

Topics: Animals; Benzofurans; Chromatography, High Pressure Liquid; Dioxins; Fishes; Gas Chromatography-Mass Spectrometry; Polychlorinated Dibenzodioxins; Polymers; Spectrophotometry; Water Pollutants, Chemical

Topics: Accidents, Home; Acne Vulgaris; Adult; Benzofurans; Child; Child, Preschool; Dioxins; Family; Female; Hexachlorobenzene; Humans; Hydrocarbons, Chlorinated; Infant; Male; Oils; Pentachlorophenol

Topics: Benzofurans; Dioxins; Graphite; Hydrocarbons, Chlorinated; Polychlorinated Biphenyls

Dibenzofuran degrading bacteria were enriched from various environmental sources. A mutualistic mixed culture of strain DPO 220 and strain DPO 230 was characterized. Strain DPO 220 alone showed limited growth with dibenzofuran as sole source of carbon and energy (td greater than or equal to 4.5 h). A labile degradation product, C12H10O5, and salicylate were isolated from the culture fluid. Salicylate was found to be a central intermediate of DBF-degradation. Strain DPO 220 co-metabolized a wide range of anellated aromatics as well as heteroaromatics. High rates of co-oxidation of dibenzodioxin demonstrate analogue-enrichment to be a powerful technique for selecting enzymatic activities for otherwise non-degradable substrates.

Topics: Bacteria; Benzofurans; Biodegradation, Environmental; Dioxins; Salicylates; Salicylic Acid

Topics: Benzofurans; Biotransformation; Dioxins; Kinetics; Pseudomonas

Structure-antitumor activity relationships are reported for a number of different examples (acridine, phenazine, anthracene, acridone, xanthenone, thioxanthenone, anthraquinone, pyridoquinazoline, dibenzodioxin, thianthrene, phenothiazine, phenoxazine, dibenzofuran, carbazole, and pyridoindole) of the general class of N-[2-(dimethylamino)ethyl] linear tricyclic carboxamides. Only the compounds containing coplanar chromophores intercalated DNA. There is an absolute requirement for an oxygen or aromatic nitrogen (possibly as hydrogen-bond acceptors) peri to the carboxamide, together with a planar ring geometry for biological activity. In addition to further delineating the nature of the pharmacophore for this class of compounds, the work has also identified dibenzo[1,4]dioxin as a novel DNA-intercalating chromophore with in vivo antitumor activity.

Topics: Aminacrine; Animals; Antineoplastic Agents; Benzofurans; Chemical Phenomena; Chemistry, Physical; Dioxins; DNA; Heterocyclic Compounds; Hydrogen-Ion Concentration; Intercalating Agents; Leukemia, Experimental; Structure-Activity Relationship; Tyramine

Topics: Animals; Benzofurans; Birds; Dioxins; Environmental Pollutants; Polychlorinated Biphenyls; Salmon; Soil Pollutants

Topics: Benzofurans; Charcoal; Chromatography, Gas; Dibenzofurans, Polychlorinated; Dioxins; Nicotiana; Plants, Toxic; Poland; Polychlorinated Biphenyls; Smoking; Tablets

Topics: Animals; Benzofurans; Carcinogens; Cattle; Dibenzofurans, Polychlorinated; Dioxins; Environmental Exposure; Female; Fishes; Humans; Male; Meat; Mice; Neoplasms; Polychlorinated Biphenyls; Poultry