Characterization, ecological and health risks of DDTs and HCHs in water from a large shallow Chinese lake

The levels of dichloro diphenyl trichloroethanes (DDTs) and hexachlorocyolohexanes (HCHs) in water from Lake Chaohu were measured. The residues, possible sources and potential ecological and health risks of these compounds were analyzed. The results show that the contents of total DDTs and HCHs in the water varied from 1.52 to 21.79 and from 1.58 to 31.66 ng L-1, respectively, which were higher than those in other Chinese lakes. The main sources of HCHs and DDTs were lindane and technical DDT, respectively. The o,p'-DDT/p, p'-DDT ratios indicated the new illegal inputs of DDT in all studied inflow rivers and some lake areas. The MOS10 (margin of safety) values suggested that the Lake was facing a potential ecological risks from p,p'-DDT, whereas the risk of gamma-HCH was small. Both carcinogenic and noncarcinogenic risks of DDTs and HCHs associated with the water use were very low. (C) 2012 Elsevier B.V. All rights reserved.