Distribution And Preliminary Health Risk Assessment Of Polvchlorinated Biphenvls And Organochlorine Pesticides In Aquatic Biotas On Different Trophic Level From Taihu Lake In China

This thesis chose seven species of aquatic biota samples (mussels, river snails, shrimps, carps, coilia nasuses, pacfic sauries, yellow catfishs) from Taihu Lake in China as the study object and determined their trophic level. The distribution of28congeners of polychlorinated biphenyls (PCBs) and8kinds of organochlorine pesticides (OCPs) of the aquatic biota in Taihu Lake was studied and a human health risk assessment was conducted to estimate the risk to local resident. The results and main conclusions are summarized as follows:PCBs and OCPs were detected in all biological samples (mussels, river snails, shrimps, carps, coilia nasuses, pacfic sauries, yellow catfishs) from Taihu Lake in China. All PCBs and OCPs were detected except CB-77, and the detection rate of PCBs is96.43%, the detection rate of OCPs is100%.The concentrations of Σ28PCBs (dry weight) of all samples are from18.75ng/g to103.79ng/g and Σ28PCBs (wet weight) of all samples are 8.67～27.60ng/g. The concentrations of Σ8OCPs (dry weight) of all samples are35.12～264.18ng/g and Σ8OCPs (wet weight) of all samples are13.98～70.26ng/g. Defferent kinds of samples made a great difference. The concentration level of PCBs and OCPs in this study locates at the middle level in the world. The concentrations of PCBs and OCPs in this study are lower than the average level in previous studies of the world.The concentrations of Σ28PCBs and Σ8OCPs of mussels, river snails, shrimps, carps, coilia nasuses, pacfic sauries, and yellow catfishs increased with the raise of their trophic level, whereas, the order is incompletely consisitent. The inconsistency may result from the biological sample’size, age, living environment, life habit, feeding habit, the change of food chain’s length and structure, fat content, sex and so forth. The exact reasons need further study. In short, bioaccumulation and biomagnification of PCBs and OCPs in biota samples from Taihu Lake was obvious.The concentrations of PCBs and OCPs in all biota samples including mussels, river snails, shrimps, carps, coilia nasuses, pacfic sauries, and yellow catfishs from Taihu Lake were within limits of GB2762-2005and GB2762-2005respectively, according to national standard. There is neither carcinogenic risk nor noncarcinogenic risk to adults by eating mussels, river snails, shrimps, carps, coilia nasuses, pacfic sauries, and yellow catfishs from Taihu Lake in this study.