Contamination and Congener Profiles of Polychlorinated Biphenyls from different agricultural top soils in a county of the Tailake Region, China

Hundred topsoil (0-20 cm) samples under different land use types were collected from a county in the Tailake Region, China and analyzed for 18 polychlorinated biphenyls (PCBs) including five dioxin-like PCBs. The mean concentration of total PCBs (Sigma PCBs) for all sites was 1.071 mu g kg(-1) dry weight (dw) with a range of 0.016 mu g kg(-1) to 4.050 mu g kg(-1), and the concentration of total Dioxin-like PCBs (Sigma Dioxin-like PCBs) was 0.352 mu g kg(-1) about 33% of Sigma PCBs. The concentration of Sigma PCBs in paddy field (PF) soils with a mean of 1.637 mu g kg(-1) was higher than that in vegetable soil with a mean of 0.882 mu g kg(-1), but the concentration of Dioxin-like PCBs in PF soil was lower than that in commercial vegetable production soil. The concentration of heavier weighted molecular PCB congeners (>= penta-PCBs) in vegetable soil accounted for 98% of EPCBs, while that in Paddy field soil for 65% of Sigma PCBs. (C) 2009 Elsevier B.V. All rights reserved.