Overview of persistent organic pollution (PAHs, Me-PAHs and PCBs) in freshwater sediments from Northern France

PCBs, parent and alkyl-PAHs have been quantified in sediments collected from three canalized rivers (Defile, Sensee and Scarpe) all located in a highly industrialized zone of the Nord Pas-de-Calais region, Northern France. Quantification using GC-MS allowed the determination of the dispersion trend, the origin as well as the relative potency of the studied sediments. Contamination depth profiles of PCBs, parents and alkyl PAHs have been studied for the three sediment cores. Total concentrations of PCBs (Sigma(28)PCBs) have revealed a higher contamination level for the Scarpe River (ranging from 126.8 to 194.4 mu g kg(-1) dw) by comparison with the Sensee River (from 15.1 to 34.0 mu g kg(-1) dw) and the Defile River (from n.d. to 15.6 mu g kg(-1) dw). Sedimentary depth profiles of total PAHs (Sigma(16)PAHs) and alkyl-PAHs (Sigma Me-18-PAHs) suggest a significant recent contamination of these three studied sites according to the high concentrations recorded in the surface of sediment cores (up to 33.7 mg kg(-1-) dw for the Scarpe River). The possible sources of PCBs have been identified through a principal component analysis, while the pyrolytic origins of PAHs have been determined using the molecular indexes. The Scarpe River reveals to be the most polluted river according to the consensus-based sediment quality guidelines. (C) 2014 Elsevier B.V. All rights reserved.