[Levels, distribution and possible sources of polychlorinated biphenyls in river sediments from an electronic waste...

The concentrations of 144 polychlorinated biphenyls (PCBs) in the river sediments from Luqiao were analyzed by GC-muECD. The objectives of this study were to understand the contents, spatial distribution and possible sources of PCBs. The Sigma PCBs concentrations detected in the river sediments were in the range of 1.66 to 5 930 ng x g(-1), with a mean of 763 ng x g(-1). Tri-CBs, tetra-CBs and penta-CBs were the primary PCB congeners in all samples, accounting for 2.63%-57.6%, 10.4%-54.6% and 7.82%-46.1%, respectively. Octa-CBs and deca-CBs were the minor PCB congeners in all samples, with the percentages of 0-8.57% and 0-11.0%, respectively. The hierarchical cluster analysis (HCA) showed that 22 samples were mainly polluted by Ar1248, 9 samples were polluted by Ar1254, and 6 samples were contaminated by Ar1016, Ar1232 and Ar1242. The PCBs concentrations found in the present study were at an upper-middle level compared with those in other studies in the world. The PCBs pollution in the present area had a high ecological risk.