chlorophyll-a and 2-2--4-4--tetrabromodiphenyl-ether

The pollution of polybrominated diphenyl ethers (PBDEs) is becoming a pressing environmental problem in aquatic environments, and its threat to aquatic organism has received much attention. In this study, Phaeodactylum tricornutum was treated with 0.8 and 4 mg L

Topics: Acetylcysteine; Chlorophyll; Diatoms; Dose-Response Relationship, Drug; Gene Expression; Halogenated Diphenyl Ethers; Lipid Peroxidation; Microalgae; Models, Theoretical; Photosynthesis; Reactive Oxygen Species; Water Pollutants, Chemical

To investigate the toxic effect and mechanism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in aquatic plants, in vivo and in vitro exposure to BDE-47 were conducted. After 14-d exposure to 5-20 μg/L BDE-47, the growth of Lemna minor plants was significantly suppressed, and the chlorophyll and soluble protein contents in fronds markedly decreased. Accordingly, the photosynthetic efficiency (Fv/Fm, PI) decreased. When the thylakoid membranes isolated from healthy fronds was exposed to 5-20 mg/L BDE-47 directly in vitro for 1 h, the photosynthetic efficiency also decreased significantly. In both the in vitro (5-20 μg/L) and in vivo (5-20 mg/L) experiments, BDE-47 led to an increased plasma membrane permeability. Hence, we concluded that BDE-47 had a direct toxicity to photosynthetic membranes and plasma membranes. However, direct effects on the activities of peroxidase (POD), malate dehydrogenase (MDH) and nitroreductase (NR) were not observed by adding 5-20 mg/L BDE-47 into crude enzyme extracts. The malondialdehyde (MDA) and superoxide anion radical (O

Topics: Araceae; Chlorophyll; Ether; Halogenated Diphenyl Ethers; Malondialdehyde; Oxidation-Reduction; Peroxidase; Reactive Oxygen Species; Water Pollutants, Chemical

The concentration and distribution of polybrominated diphenyl ethers (PBDEs) in the dissolved phase (DP) and suspended particulate matter (SPM) of seawater and in surface sediment obtained from Jiaozhou Bay (JZB) were determined. The potential sources of these compounds were evaluated. The total concentrations of 14 PBDEs (∑14PBDE) in DP and SPM were 0.09-1.35 and 1.17-5.45ng/L, respectively, indicating that the PBDE congeners are predominantly partitioned into the SPM fraction. The ∑14PBDE concentrations in sediment ranged from 2.18ng/g to 10.59ng/g with a mean value of 6.59ng/g. BDE-209 was dominant among 14 PBDE congeners, and BDE-47 was another abundant congener in the SPM and sediment samples. The PBDE concentration in SPM showed a significantly positive correlation with chlorophyll a level (r(2)=0.496, p<0.05), and that in the sediment exhibited a significantly positive correlation with clay proportion (r(2)=0.846, p<0.01). This result suggests that the phytoplankton or debris in the suspended particulates play an important role in PBDE accumulation and transportation and that PBDEs are preferentially enriched in clays in the sediment. PBDE concentrations were higher in the inner and mouth regions than in the outer and middle regions, and decreased with water depth in the water column. Non-parametric multidimensional scaling ordination showed that BDE-209 and BDE-47 are the important products discriminating PBDE contamination. This result is associated with industrial waste discharge from urban areas and with heavy ship traffic, indicating that DecaBDE and PentaBDE products are the potential sources of PBDEs. PBDE concentrations were lower in the sediment in JZB than in other coastal areas in South China, although the PBDE concentrations in DP were higher than those in some coastal areas worldwide. Moreover, the PBDE concentrations in DP and sediment increased in the last decade.

Topics: Bays; China; Chlorophyll; Chlorophyll A; Environmental Monitoring; Geologic Sediments; Halogenated Diphenyl Ethers; Industrial Waste; Seawater; Water Pollutants, Chemical

Polybrominated diphenyl ethers are ubiquitous and toxic contaminants in aquatic environments. The effect of polybrominated diphenyl ether BDE-47 on five species of cyanobacteria, along with their removal ability was investigated. Four species, namely Synechocystis sp., Oscillatoria planctonica, Microcystis flos-aquae and Nostoc sp., were exposed to BDE-47 at concentrations ranging from 0.05 to 1.0 mg L

Topics: Chlorophyll; Cyanobacteria; Drug Tolerance; Glutathione Transferase; Halogenated Diphenyl Ethers; Lipids; Photosynthesis

Little is known about the fate of polybrominated diphenylethers (PBDEs) across the Oceans. Air and water were sampled using both active and passive polyethylene samplers on an east-west transect across the tropical Atlantic Ocean in 2009 and analyzed for PBDEs. Typical particle-bound concentrations of PBDEs in the surface water were low, at <1 pg L(-1). Truly dissolved concentrations from passive samplers were ∼0.5 pg L(-1) for BDE 47 and around 0.1 pg L(-1) for BDEs 28, 99, and 100 (results from active samples were compromised). In the atmosphere, particle-bound BDE 209 dominated overall concentrations (median 1.2 pg m(-3)), followed by BDE 99 (0.13 pg m(-3)). Gas-phase concentrations based on passive samplers were 1-8 pg m(-3) for BDE 47 and ≤ 4 pg m(-3) for BDE 99. Net air-water exchange gradients strongly favored gas-phase deposition of PBDEs into the water. Net gas-phase deposition fluxes ranged from tens of pg m(-2) day(-1) for BDEs 28 and 85 to around 1 ng m(-2) day(-1) for BDE 47, 99, and 209. Settling fluxes of particle-bound PBDEs in the atmosphere and surface water were around 50 pg m(-2) day(-1) for BDE 47 and <10 pg m(-2) day(-1) for the other congeners.

Topics: Air; Atlantic Ocean; Chlorophyll; Environmental Monitoring; Gases; Halogenated Diphenyl Ethers; Particulate Matter; Polybrominated Biphenyls; Ships; Time Factors; Tropical Climate; Water; Water Pollutants, Chemical