BaselinePolychlorinated biphenyls and organochlorine pesticides in surface sediments from Shantou Bay, China: Sources, seasonal variations and inventories

•PCBs and OCPs were analyzed in surface sediments from Shantou Bay, China for the first time.•Source identification showed that usage of antifouling paint still served as a significant source of sediment DDT.•Atmospheric deposition and surface runoff played an important role in distribution of historical pollutants.•It cannot be neglected on POPs from numerous of small river estuaries to the global ocean.

Sediments from Shantou Bay, China, were analyzed for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) for the first time. The concentrations of PCBs and OCPs were 0.54-55.5 ng g− 1 and 2.19-16.9 ng g− 1 (dry weight), respectively. Source identification showed that tri-CBs and penta-CBs were manufactured and used in the last century, while usage of antifouling paint might still serve as a significant source of sediment DDT. Concentrations of PCBs and HCHs significantly (p < 0.05) increased after wet season, suggesting that atmospheric deposition and surface runoff played an important role in distribution of historical pollutants. Additionally, the adverse biological effects could occasionally occur for DDT in sediments. The mass inventories were preliminarily calculated for PCBs (90.1 ng cm− 2 and 0.09 tons) and OCPs (61.8 ng cm− 2 and 0.062 tons) in Shantou Bay, while as part of the “reservoir” of organochlorine compounds to the global ocean, its role cannot be neglected.