Sediment-adsorbed polybrominated diphenyl ethers (PBDEs) along the coast of China: Distribution characteristics,...

Due to the anthropogenic activities, marine sediments have become an aggregation sink for highly hydrophobic and lipophilic polybrominated diphenyl ethers (PBDEs) in China. Previous studies have focused on bays and rivers in a single region, which was difficult to macroscopically describe the fate of PBDEs in the sediment environment. In this study, national-scale analysis of PBDEs in China's marine sediments (Bohai Sea (BS), East China Sea (ECS), Yellow Sea (YS), and South China Sea (SCS)) revealed BDE-15, BDE-47, and BDE-209 as dominant congeners. ECS sediments showed the highest average concentration (12.9 μg/kg dw), 2.2 times higher than YS. Socio-economic, geographic, and environmental factors directly influenced PBDEs accumulation or indirectly affected residues via sediment properties. A level Ⅲ fugacity-based multimedia model indicated atmospheric deposition as the primary input source, especially for SCS sediments. These compounds in the atmosphere were discharged into seawater/land through dry/wet deposition, where BDE-47 and BDE-209 had higher mass transfer capacity in sediment media. The non-carcinogenic risks of PBDEs in ECS, SCS, and BS sediments were 1.9-2.4 times that of YS, but the residual PBDEs could have no significant risk on population health. These results provide basic information for improving China's marine environmental management and PBDEs pollution assessment.