Organochlorine pesticides in soils from a typical alluvial plain of the Yangtze River Delta region, China.

Residues of organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), their risks and affecting factors in 544 representative soils collected from a typical alluvial plain of the Yangtze River Delta region, China, were investigated. Mean concentrations of ΣDDT and ΣHCH in soils were 88.8 and 99 ng/g, respectively. Historical application of DDT and HCH were the major sources of their residues in soils. Concentrations of DDT in soils had relative greater levels of contamination, while concentrations of HCH were almost at safe levels. Residues of DDT and HCH in soils were affected by soil types as well as soil textures.