nitrogen-dioxide and 1-nitropyrene

In this paper, the state of the art of the chemical characterization of diesel particulates in Japan is presented. However, some of these results are only preliminary. The principal contents may be summarized as follows: Characterization of Diesel Particulates; Examples of the application of the chemical characterization to various studies are described. Measurements for elemental composition and distributions of molecular weight and boiling point of diesel particulates and related samples were carried out to gain a better understanding of the main components of diesel particulates. Determinations of carbonaceous components, elemental carbon and organic carbon, in diesel particulates were made by a thermal carbon analyzer, and these results were applied to the study of the relations between such components and the driving conditions of diesel vehicles and to the estimate of emission rates of carbonaceous components from on-road diesel vehicles in a highway tunnel. It seems that the thermal carbon analyzer can be used to advantage in the determination of such carbonaceous components. Artifacts of PAH and 1-NP during Collection of Diesel Particulates; In order to minimize the artifacts of PAH during collection of diesel particulates, three methods were investigated for the artifacts of BkF, BaP and BghiP; two methods incorporated the removal of reactive gaseous components such as NO2, with an ACF method and an impinger method, and the third was a high dilution sampling method. These results suggest that the high dilution sampling method is very promising. From the results of various studies including model experiments, it is clear that the artifact formation of 1-NP is of first order dependence on total amounts of nitrate on carbon black and diesel particulates, not on gaseous nitric acid, although second order dependence of the artifact formation on NO2 concentration is ambiguous. Aside from the above studies, the relation between 1-NP concentrations in diesel exhaust and NO2 concentrations in the dilution tunnel with changing the dilution ratio at a fixed driving condition was utilized for an estimate of the artifact formation of 1-NP, and the estimated results are discussed in connection with the reaction order of the artifact formation on NO2 concentration. Concentrations of Various Components in Diesel Exhaust and Ambient Air; Analytical results are presented for the PAH, mononitro-PAH and dinitro-PAH in particulate samples collected from the exhaust o

Topics: Air; Carbon; Japan; Mutagenicity Tests; Nitrates; Nitric Acid; Nitrogen Dioxide; Polycyclic Compounds; Pyrenes; Vehicle Emissions

Particulate concentrations of polycyclic aromatic compounds (PACs) including, 17 polycyclic aromatic hydrocarbons (PAHs), 9 oxygenated PAHs (OPAHs) and 18 nitrated PAHs (NPAHs) were determined at traffic and suburban sites located in the region of Paris. A 12 h sampling basis time resolution was applied in order to study their diurnal and nocturnal variations. Observed concentrations were about 10 times higher at the traffic site for all compounds and were higher during the night-time for both sites (except for NPAHs at the traffic site). No significant differences in PAH and OPAH profiles were observed at both sites whereas, for NPAHs, 1-nitropyrene (diesel source) was the most abundant at the traffic site and 2+3-nitrofluoranthene (secondary formed by gas-phase reaction) was predominant at the suburban site. The study of the specific ratio 2-nitrofluoranthene/1-nitropyrene (2-NFlt/1-NP) showed a local formation of NPAHs in gaseous phase at the suburban site. A detailed analysis showed that atmospheric humidity and rainfalls modified differently PAH and NPAH profiles, in comparison to OPAH. A difference of the scale variability of water solubility between, light (MW≤228 g mol(-1)) and heavy compounds (MW≥273 g mol(-1)), could explain these observations. The specific study of the relationships between PACs and other measured pollutants highlighted that particle resuspension could constitute a significant source of PM on the traffic site. Even if NPAH formation seemed clearly evident at the suburban site during periods characterised by high O(3) and NO(2) concentration levels, results showed also that the primary and/or secondary origins of OPAHs and NPAHs were strongly dependent on the sampling site and on sampling conditions. Finally, we conclude that higher time sampling resolutions would be helpful in investigating the atmospheric chemistry and behaviours of PACs in correlation with the local meteorological variations and the daily cycle of human activities.

Topics: Air Pollutants; Environmental Monitoring; Fluorenes; Humans; Nitrogen Dioxide; Ozone; Paris; Particulate Matter; Polycyclic Aromatic Hydrocarbons; Pyrenes; Vehicle Emissions

The particulates in a room warmed with a radiant kerosene heater were collected, extracted and fractionated into diethyl ether-soluble neutral, acidic and basic fractions. The mutagenicity of these fractions was measured with Salmonella typhimurium strains TA98, TA98NR, TA98/1,8-DNP6 and TA100 in the presence and absence of S9 mix. Room air without the heater showed very low mutagenicity. However, a sample from a room at the beginning of the burning period showed very high mutagenicity (237 His+ revertants/plate/m3 of air in strain TA98 in the absence of S9 mix). In contrast, emissions from the heater after it was burning stably showed low mutagenicity (9 His+ revertants/plate/m3). The crude extract of particulates from the heater at the beginning of the burning period was analyzed by high-pressure liquid chromatography (HPLC) and showed a considerable amount of nitropyrenes (NPs); the concentrations of 1-NP and 1,6-diNP were 1.62 ng and 0.149 ng/m3 of air, respectively, and accounted for 1.2% and 17.6%, respectively, of the mutagenicity in strain TA98 in the absence of S9 mix. In addition, an HPLC-Ames histogram showed that peaks of mutagenicity corresponding to 1-NP and diNPs accounted for 75.7% (1-NP, 4.9%; 1,6-diNP, 17.1%; 1,8-diNP, 46.3%; 1,3-diNP, 7.4%) of the HPLC-recovered mutagenicity for strain TA98 without S9 mix. These results that kerosene heaters, especially immediately after ignition, create mutagenic substances such as NPs.

Topics: Air Pollutants; Chromatography, High Pressure Liquid; Heating; Kerosene; Mutagens; Nitrogen Dioxide; Petroleum; Pyrenes

The urine of mice injected intraperitoneally with pyrene during exposure to NO2 was found to contain highly mutagenic compounds by means of the Ames test using Salmonella typhimurium strain TA98. The mice were exposed to 20 ppm NO2 for 3 days before intraperitoneal injection of pyrene (800 mg/kg of body weight). The pyrene-treated mice were further exposed to NO2 for an additional 24 hr, and the urine from the mice was collected in ice-cooled containers and stored frozen in the dark. The collected samples were treated with beta-glucuronidase and passed through activated Sep-Pack C18 cartridges. After elution with methanol, the effluent was concentrated and the residue was dissolved in dimethyl sulfoxide (DMSO). The DMSO solution was fractionated by high-performance liquid chromatography and the mutagenicity of each fraction was assayed with S. typhimurium strain TA98. The mutagenic compounds 3-hydroxy-1-nitropyrene, 6-hydroxy-1-nitropyrene, 8-hydroxy-1-nitropyrene, and 1-hydroxypyrene were identified in the mutagenic fractions by mass spectrometry and UV-visible spectrophotometry with synthetic reference substances. These mutagenic compounds may have been formed by either nitration of hydroxylated pyrene, or hydroxylation of 1-nitropyrene, which is formed in vivo from pyrene and NO2, or the simultaneous occurrence of these two reactions in the mouse body.

Topics: Animals; Biotransformation; Chromatography, High Pressure Liquid; Cocarcinogenesis; Hydroxylation; Male; Mice; Mutagens; Nitrogen Dioxide; Pyrenes