Spatial distribution and sources of polychlorinated biphenyls in surface sediments from the Zhoushan Archipelago and Xiangshan Harbor, East China Sea

• Mixed PCB sources were found in Zhoushan Archipelago and Xiangshan Harbor.
• Atmospheric deposition and PCB dispersion from paint flakings were the main PCB pollution sources.
• Aroclor 1245 and Clophen A50 were the potential PCB sources in the research area.

This study investigated ambient concentrations and potential sources of polychlorinated biphenyls (PCBs) in surface sediments from the Zhoushan Archipelago and adjacent Xiangshan Harbor. The ∑ 18PCB (total 18 PCB) concentrations ranged between 1.48 and 7.94 ng/g d.w., average at 4.20 ng/g d.w., presenting a low adverse environmental risk. Penta-CB was the dominant congener, contributing 46.01%–86.44% of the total PCBs. Concentrations of PCBs were highest in the northeastern part of the Zhoushan Archipelago and Xiangshan Harbor. Principal component analysis (PCA) showed that PCBs have a mixed origin; atmospheric deposition and PCB dispersion from paint flakings being the main sources of PCB pollution. Aroclor 1245 and Clophen A50 were the potential PCB sources in all sampling sites. This paper provides the first intensive survey and statistical analyses of PCB distributions and sources in the Zhoushan Archipelago and adjacent Xiangshan Harbor. This study may provide a reference to environmental protection and monitoring of PCB pollution in the East China Sea.