Organchlorinated pesticides in surface sediments of Meiliang Bay in Taihu Lake, China.

The concentration level of organochlorine pesticides (OCPs) in sediments from Taihu Lake, China was investigated to evaluate the potential ecological risk. A total of 48 surface sediment samples were collected in Taihu Lake. Meiliang Bay in Taihu Lake was selected due to its importance as a drinking water source for nearby cities. Results show that the concentrations of various pesticides in sediments were in the range of 0.1-107.3 ng/g for HCH, 3.5-50.5 ng/g for endosulfan sulfate, 2.7-23.0 ng/g for endosulfan II and 0.3-59.3 ng/g for DDT. Among the OCPs, HCHs and DDTs were the most dominant contamnants in the sediments. Cyclodiene compounds were also the main pesticides in Taihu lake besides HCH and DDT. Among the cyclodiene compounds, heptachlor and endosulfan sulfate prevailed in most of the sediments. Moreover, the frequencies of detection for the metabolites of PAHs were higher than those of parent compounds, depicting that the sediments have been contaminated historically. The results obtained in this study shown that there still exist a variety of OCPs residues in Taihu Lake and Meiliang Bay.