title: Topsoil dichlorodiphenyltrichloroethane and polychlorinated biphenyl concentrations and sources along an urban-rural gradient in the Yellow River Delta.
abstract: The Yellow River Delta (YRD) is a typical agricultural and petrochemical industrial area of China. To assess the current status of soil dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB) residues, topsoil samples (0-15 cm) (n = 82) were collected in Bincheng District, at the geographic center of the YRD. The total concentrations of six DDT homologues were within 3.3-3819 microg/kg, with a mean concentration of 191 microg/kg, showing significant increase along urban-rural gradient. Soil concentrations of seven indicator PCBs in the area ranged from non-detectable to 87.0 microg/kg, dominated by heavily chlorinated PCBs (PCB-101 and -118). Soil PCBs concentrations were significantly greater in urban than suburban and rural areas. Principal component and multiple linear regression analysis suggest that 86.4% of soil DDTs originate from past DDT usage, and 13.6% originate from dicofol application. Soil PCBs most likely originate from the petrochemical industry (77.1%), municipal solid waste disposal (16.5%), local commercial PCB homologues usage (5.2%), and long-range atmospheric deposition (1.2%). In general, soil DDTs pollution was classified as low level, and mean PCBs concentrations were below the severe contamination classification range. Because PCB-118 is a dioxin-like congener, monitoring and remediation is advised to assess and reduce negative environmental and human health effects from soil DDTs and dioxin-like congeners in the study area.
authors.affiliation: Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta, Binzhou University, Binzhou 256603, China. xwjeric@yahoo.com.cn
authors.forename: Wenjun
authors.initials: W
authors.lastname: Xie
authors.forename: Aiping
authors.initials: A
authors.lastname: Chen
authors.forename: Jianyong
authors.initials: J
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Hongjun
authors.initials: H
authors.lastname: Yang
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Lu
mesh_terms: D002681:China; D003634:DDT / Q000737:chemistry*; D004784:Environmental Monitoring; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D045483:Rivers; D012424:Rural Population; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D014505:Urban Population; D014872:Water Movements
chemical_list: D012987:Soil; D012989:Soil Pollutants; D003634:DDT; D011078:Polychlorinated Biphenyls