Organochlorine pesticides in tree bark and human hair in Yunnan Province, China: Concentrations, distributions and exposure pathway

摘要

The concentrations and distributions of organochlorine pesticides (OCPs) in West China were investigated and internal and external exposure of humans to OCPs were assessed by analyzing samples of human hair and tree bark collected in Kaiyuan, in Yunnan Province, China Dichlorodiphenyltrichloroethane and its metabolites (collectively called DDTs), hexachlorocydohexanes (HCHs), and hexachlorobenzene (HCB) were the dominant OCPs in the human hair and tree bark samples. The mean total DDT, total HCH, and HCB concentrations in the tree bark samples were 298 pg/g dry weight (dw), 100 pg/g dw, and 183 pg/g dw, respectively, and the mean total DDT, total HCH, and HCB concentrations in the hair samples were 2850 pg/g dw, 348 pg/g dw, and 1026 pg/g dw, respectively. The results indicated that relatively new DDT and lindane inputs have occurred in the study area. DDT and lindane may have been released in products that are used locally. The HCB in the environment in the study area is mainly supplied by long-range atmospheric transport. External exposure was found to be the main factor controlling the p,p'-DDT, γ-HCH, and HCB concentrations in human hair, whereas p.p'>-DDE and β-HCH were found to be mainly controlled by internal exposure.