Bioaccumulation behavior of polybrominated diphenyl ethers (PBDEs) in the freshwater food chain of Baiyangdian lake, north China.

Polybrominated diphenyl ethers (PBDEs) are of great environmental concern due to bioaccumulation in different food chains. Trophodynamics of PBDEs in freshwater food chain is an important criterion for assessing their ecological risk. In the study, PBDEs were analyzed in sixteen aquatic species collected from Baiyangdian Lake, North China. The concentrations of nine PBDE congeners (BDE-28, -47, -66, -99, -100, -85, -153, -154, and -183) in aquatic organisms ranged from 3.4 to 160.2ng/g lipid weight. BDE-47 was the predominant PBDE congener in most samples except for river snails and swan mussels. BDE-209 was detected in 50% of biota samples, which indicated the bioavailability of BDE209. Correlation between lipid-normalized concentrations of PBDEs and trophic levels determined by stable isotope nitrogen technologies confirmed that PBDEs were biomagnified in the freshwater food chain. The trophic magnification factors (TMFs) ranged from 1.3 to 2.1 for PBDE congeners, greater than one, indicating the biomagnification potential for the PBDE congeners in the freshwater food chain. The relationship between TMFs and Log K(ow) (octanol-water partition coefficient) indicated that the phenomenon of trophic magnification for lowly brominated congeners was obvious in the freshwater food chain.

[Distribution characteristic of organochlorine pesticides and polybrominated diphenyl ethers in tissues of ducks from Baiyangdian Lake, North China].

The concentrations of hexachlorocyclohexane (HCHs), dichlorodiphenyltrichloroethane (DDTs), and polybrominated diphenyl ethers (PBDEs) in muscle, liver and brain of ducks from Baiyangdian Lake were determined by gas chromatography coupled with mass spectrometer (GC/MS). The results showed that the concentrations of HCHs, DDTs and PBDEs in various tissues of ducks were in the range of 0.9-5.0 ng/g wet weight (WW), 0.3-2.8 ng/g (WW) and 0.03-0.65 ng/g (WW), respectively. Statistical analysis indicated that the accumulation of DDTs and PBDEs in muscle, liver and brain was significantly different (p < 0.05), but not with HCHs (p > 0.05). Liver tissues contained the highest DDTs and PBDEs levels, with average concentrations of 2.3 ng/g (WW) and 0.37 ng/g (WW), respectively. Among the HCH isomers and DDT metabolites, beta-HCH was the predominant isomers in liver and brain tissues, and p,p'-DDE was the dominant metabolites of DDTs in various tissues. Among the PBDE congeners, BDE47 and BDE99 were the predominant in various tissues. The different profiles of persistent organohalogen compounds in various tissues of ducks may reflect that the Baiyangdian Lake still subject to the contamination of historically residue for HCHs and DDTs. In addition, the source of PBDEs was partly attributed to the industrial pollution, chemical plants, and sewage discharging.

Brominated flame retardants, polychlorinated biphenyls, and organochlorine pesticides in captive giant panda (ailuropoda melanoleuca) and red panda (Ailurus fulgens) from China.

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BFRs) were investigated in captive giant and red panda tissues from China. The total concentrations of OCPs, PCBs, and polybrominated diphenyl ethers (PBDEs) in tissues ranged from 16.3 to 888 ng/g lipid weight (lw), 24.8 to 854 ng/g lw, and 16.4 to 2158 ng/g lw, respectively. p,p'-DDE and beta-HCH were major OCP contaminants. PCBs 99, 118, 153/132, 170, 180, and 209 were the major contributing congeners determined. Among PBDEs, congener BDE-209 was the most frequent and abundant, followed by BDE-206, BDE-208, BDE-207, BDE-203, BDE-47, and BDE-153. Decabromodiphenyl ethane (DeBDethane) was detected in 87 and 71% of the giant and red panda samples with concentrations up to 863 ng/g lw, respectively. The remarkable levels and dominance of BDE-209 and DeBDethane may relate to significant production, usage, or disposal of BFRs in China. The positive significant correlation between concentrations of PBDEs and PCBs in captive pandas may suggest that the exposure routes of PBDEs and PCBs to panda are similar. To our knowledge, this is the first report of the occurrence of DeBDethane in captive wildlife samples. Therefore, further studies are warranted to better understand DeBDethane production, transport, uptake, and toxicological effect.