Residues and Risk Assessment of Soil OCPs in a City of Guizhou Province

To determine the residues of OCPs and evaluate the potential ecological risk in the soil, the samples were collected from three counties in Guizhou Province and eleven kinds of OCPs were quantified by gas chromatography.The results showed that the major components of OCPs residues were DDTs and HCHs. The concentration of DDTs residues was higher than that of HCHs. The concentration of HCHs in the soil was in the range of ND- 4.907 μg kg-1,with an average of 0.303 μg kg-1, while the concentration of DDTs ranged from 0.115 to 29.900 μg kg-1, with an average of 0.303 μg kg-1. The concentrations and the metabolins of OCPs indicated that the residues of HCHs and DDTs in the soil were mainly originated from the early residues, while the hexachlorobenzene was mainly from the atmospheric deposition. The results from RBCA health risk evaluation model demonstrated that the health risk caused by OCPs was low.