DISTRIBUTION OF ORGANOCHLORINE PESTICIDES IN SURFACE SOIL OF THE YELLOW RIVER DELTA AND ECOLOGICAL RISK ASSESSMENT

Thirty-seven surface soil samples collected from the Yellow River Delta were analyzed for organchlorine pesticides (OCPs) residues. Data show that the contents of OCPs in the soil vary between 0.04~1.19ng/g (with a mean of 0.47ng/g) for HCHs, but 0.05~6ng/g (with a mean of 0.85 ng/g) for DDTs. High percentage of β-HCH、DDE in most sites indicates that they were from the pesticides residues in the soil. The ecological risk assessment suggests that the OCPs in the surface soil of this area remain at a low level and bear no environmental risk to human society.