Polybrominated Diphenyl Ethers And Polychlorinated Biphenyls In Fish From Taihu Lake, China: Their Levels, Biomagnification, And Human Health Risk Assessment

Polybrominated diphenyl ethers （PBDEs） and polychlorinated biphenyls （PCBs）are a class of typical persistent organic pollutants （POPs）, which are generallycharacterized by properties of persistence, bioconcentration, toxicity and a long-rangeglobal transport. Because of their high lipophilicity, PBDEs and PCBs are capable ofbioconcentration and biomagnification through food chains. Diets are one of themajor sources of PBDEs and PCBs exposed to human.In this study, the concentrations of13PBDE and32PCB congeners weredetermined in200samples of24fish species collected from Taihu Lake. The resultsshowed that PBDEs and PCBs could be detected in all samples, with the average totalconcentrations of PBDEs and PCBs in each species ranging from8.6to74.3ng/g lwand from10.3to165.2ng/g lw, respectively. The lowest and highest concentrations ofPBDEs and PCBs were observed in S. dabryi and S. asotus, respectively. Comparedwith those in wild freshwater fish in other studies in China, fish in Taihu Lake aremoderately contaminated by PBDEs and PCBs. PBDEs and PCBs were detected withBDE47,209, and154were the most abundant congeners for PBDEs, and PCB153,138, and28for PCBs. BDE47accounted for10.8⁵2.7%of the total PBDEs.PCB153accounted for12.1²4.9%of the total PCBs. The correlation analysisbetween the concentrations of PBDEs and PCBs suggested they might have the samesources or similar bioaccumulation behaviors.The TMFs of individual PBDE and PCB congeners ranged from0.78to2.95andfrom0.92to2.60, respectively. Parabolic relationships were observed between theTMFs and logKOW, as well as between the TMFs and the molecular volumes ofPBDEs and PCBs. The congeners with logKOWvalues of approximately7ormolecular volume of approximately8.13×10^-5nm³had the greatest biomagnificationpotentials. Compared to molecular weight, molecular volume seems to be the betterstandard for analyzing the influence of molecular size on biomagnification. Fish sizemight influence the biomagnification evaluation, because different sized fish had different lipid content, leading to different lipid-based concentrations of PBDEs andPCBs.Finally, on the basis of trophic levels, the potential human health risks posed viafish consumption considering multiple contaminants for both carcinogenic andnon-carcinogenic effects were assessed. The daily intakes of PBDEs were0.12to0.96and0.11to0.84ng/kg bw d for chidlen and adults, respectively, and those for PCBswere0.23to1.28and0.20to1.12ng/kg bw d, respectively. The total daily intake ofPBDEs, PCBs, OCPs and PAHs was2.02to12.57and1.76to10.95ng/kg bw d forchidlen and adults, respectively. The daily intake for children and adults and hazardquotient increased with the trophic levels increasing. Compared with fish at lowertrophic position, fish at higher trophic position had relative higher health risks becauseof fish consumption. In view of the contaminants for carcinogenic effects, DDTs wasthe contaminant which posed the highest risk to humans. However, whennon-carcinogenic effects of the contaminants were considered, PCBs posed thehighest risk. The risk caused by PBDEs was negligible.