Typical persistent organic pollutants (POPs) in sediments from the Yellow and East China Seas and adjacent coastal areas, China

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), short-chain chlorinated paraffins (SCCPs), polybrominated diphenyl ethers (PBDEs) and perfluoroalky chemicals (PFCs) are five kinds of typical persistent organic pollutants (POPs), which can be transported from emission sources to marine environments via many pathways, including riverine inputs, surface runoff of contaminated soils and atmospheric deposition. Due to their hydrophobicity and lipophilicity, they are preferentially adsorbed onto particles with higher organic contents and finally buried in marine sediments, which are generally regarded as one of the major sinks of POPs. Once absorbed by organisms, they are more easily accumulated in tissues with higher lipid contents. Meanwhile, under certain weather and environmental conditions, POPs adsorbed on sediments can be re-released to aquatic environments, leading to secondary pollution of water systems. POPs are of environmental persistence, bioaccumulation and biomagnification in biota and long-range transport potential, and thus may cause seriously adverse effects on marine ecosystems after they entered into marine environments. These effects are important to the safety of marine system. The present review mainly summarizes the pollution characteristics of the above POPs in sediments from the Yellow and East China Seas and adjacent coastal areas, China. In addition, their potential sources, mechanisms for migration from the land to the sea, as well as the ecological risk assessment for some of these POPs, are also reviewed. Future researches urgently needed are proposed.