Residues of organochlorine pesticides in water and suspended particulate matter from the Yangtze River catchment of Wuhan, China

The residues of 13 organochlorine pesticides (OCPs) in surface water and HCHs and DDTs in suspended particulate matter (SPM) from rivers and lakes in Yangtze River catchment of Wuhan, China, were investigated. The concentration of total OCPs in surface water varied from 1.01 to 46.49 ng l(-1) (mean 10.55 ng l(-1)). The levels of total HCHs (Sigma HCH) and total DDTs (Sigma DDT) in surface water were in the range of 0.55-28.07 ng l(-1) and lower than detection limit to 16.71 ng l(-1), respectively, which was lower than Chinese standards on the whole. For OCPs residues in SPM, the mean levels varying from 0.20 to 34.72 ng l(-1) and 0.46 to 2.72 ng l(-1) for Sigma HCH and Sigma DDT, respectively, which ranked the relatively higher levels among Chinese studied rivers. Results from this investigation showed that previous excessive usage of technical OCPs was the main reason for the residues of HCHs and DDTs both in surface water and SPM, although some new sources were likely to occurred in the region. Apart from the OCPs in SPM originated from upstream in flood season, one of the important sources of OCP residues both in water and SPM in Yangtze River was supposed to be the inputs of its tributaries. Additionally, in situ water-SPM phase distributions of OCPs indicated that HCHs tended totransport with water as well as DDTs was prone to combine with SPM in Yangtze River catchment of Wuhan.