Concentration and composition of polychlorinated biphenyls in the water of the East China Sea

The East China Sea (ECS) is considered a heavily polluted area of polychlorinated biphenyls (PCBs) due to the input of industrial wastewater from the Yangtze River, Fujian and Zhejiang coastal runoff and emissions from adjacent e-waste disposal sites.In this study, eleven surface water samples were collected from the ECS to determine the occurrence of PCBs in the seawater by the "Science Ⅲ" scientific research ship during October 2012.The PCB concentrations of the water from ECS ranged from 0.59 to 1.68 ng/L, and the values were at a middle-low level compared with other studying areas.There was a significant negative correlation between concentration of PCBs and salinity, indicating that the coastal runoff was an important way for PCBs transport in the ECS.The profile of PCB homologues was dominated by less chlorinated compounds, i.e.tri-PCBs, tetra-PCBs and penta-PCBs, which related to the historical production and usage of PCBs in china.The concentrations of different PCB congeners were consistent with the theoretical ones which obtained from the Kow values, indicating the physicochemical properties was an important factor affecting the occurrence of PCBs in the water.Besides, a relatively higher abundance of hexa-PCBs was observed in the seawater from the ECS, hinting that the e-wastes treatment emissions from coastal areas might be a potential source.