Levels and distribution of organochlorine pesticides in shellfish from Qiantang River, China.

Various shellfish collected from different locations along the Qiantang River in 2006 were analyzed for the levels of 13 organochlorine pesticides (OCPs) in order to elucidate the status of OCPs pollution in shellfish for human consumption. Total concentrations of OCPs in shellfish ranged from 16.9 to 78.6 ng/g wet weight (ww), with HCHs (alpha-, beta-, gamma-, delta-HCH), DDTs (p,p'-DDD, p,p'-DDE, p,p'-DDT, o,p'-DDD) and other OCPs (aldrin, diedrin, endrin, heptachlor and heptachlor epoxide) in the range of 3.33-13.2, 8.38-40.1 and 2.32-14.3 ng/g ww, respectively. The dominant OCPs in shellfish were p,p'-DDE among DDTs, beta-HCH among HCHs and heptachlor epoxide among other OCPs. It is noticeable that higher OCPs biota-sediment accumulation factor (BSAF) occurred at site with high concentration of OCPs in sediments. The field bioconcentration factor (BCF) increased exponentially with the increase of Kow (octanol-water partition coefficients) of the OCPs. Concentrations of DDTs and HCHs in shellfish from Qiantang River kept at middle level compared with those from marine environment. The concentrations of DDTs in more than 50% of edible shellfish in this study were higher than the limit of 14.4 ng/g ww for human consumption recommended by US EPA (2000).