Congener specific distribution and bioaccumulation of short-chain chlorinated paraffins in Liao estuary

Short-chain chlorinated paraffins(SCCPs) is a new candidate of persistent organic pollutants by the "Stockholm Convention". In this study, the occurrence, congener specific profiles, source and biota-sediment accumulation factor(BSAF) of SCCPs in sediments and biota samples collected from the Liao river estuary were investigated. The concentrations of SCCPs range from 64.9 to 1683.4 ng/g dw(mean 419.7) in the sediments and 1.55 to 11.9 μg/g dw(mean 6.14). C10 and C11 homologue groups of SCCPs are predominant in the sediments and organism with the summed relative contribution of 69.5% and 84.0%, respectively. Cl5, Cl6 and Cl7 congeners are the main congener groups in the sediments and organisms with the total relative contribution of 84.5% and 90.8%, respectively. The results also imply that the major pollution sources of SCCPs in this area are the productive activities and usage of CP-42 and CP-52, and one major source route is the riverine input. The average BSAF of ∑SCCPs(2.34) is higher than 1 shows an obvious bioaccumulation in mollusks. Significant negative correlation between BSAF and chlorine atoms(P0.05) is observed, indicating that the behavioral enrichment of zoobenthos and fish are quite different due to the influence of physicochemical properties and feeding way.