Levels and distribution of organochlorine pesticides and hexachlorobutadiene in soils and terrestrial organisms from a former pesticide-producing area in Southwest China

Abstract

The contamination of organochlorine pesticides (OCPs) and hexachlorobutadiene (HCBD) in soils, plants, and terrestrial fauna from a former pesticide-producing area in Southwest China was investigated. High levels of OCP residues (ΣHCHs and ΣDDTs of 3.89–13,386 and 23.3–11,186 ng g−1 dw, respectively) were found in the soils within the producing factory, indicating that the former pesticide factory brownfield site poses a high environment risk and that effective soil remediation is needed. The OCP concentrations in soils surrounding the pesticide factory were 1–2 orders of magnitude higher than in the other agricultural areas from China. Grass, vegetables, and tree leaves from the surrounding areas of the point source showed moderate OCP pollution, which was likely to be causing potential negative impacts on terrestrial ecosystem. OCP levels in terrestrial species from the studied area including insects, free-range chickens and birds were moderate, and were generally within accepted safe levels. β-HCH was the most prevalent isomer, implying that hexachlorocyclohexane (HCH) residues were mainly derived from the degradation of technical HCH. The dichlorodiphenyltrichloroethane (DDT) profiles reflected obvious degradation of technical DDT. In the study area, the concentrations of HCBD were <0.02–5.59, 0.03–24.6 ng g−1 dw and 1.65–3.80 ng g−1 lw in soils, plants, and animals, respectively, which were relatively low and not sufficient to cause observable adverse biological effects.