Distribution of polybrominated diphenyl ethers in the surface sediment of the East China Sea

The concentrations of polybrominated diphenyl ethers(PBDEs)were determined in the surface sediments of 20 locations in the East China Sea(ECS).The P PBDEs(sum of 13 PBDE congeners,without brominated diphenyl ether 209(BDE209)ranged from 2.6 to 49 pg g-1(dry weight)with an average of 21 pg g-1,which fell at the low end of the global range.The spatial distribution presented an offshore decreasing trend towards the outer shelf and along the coastline,suggesting a direct influence of the inputs by the Yangtze River.The P PBDE concentrations were influenced by the total organic carbon of the sediment,as demonstrated by their similar spatial distributions.The P C27?C29?C31n-alkanes concentrations and sand%reported in the literature for sediments in the ECS presented similar spatial distributions as P PBDEs,which suggests that a considerable part of P PBDEs may come from the Yangtze River and that grain size plays an important role in PBDE accumulation.The three dominant congeners were BDE28(19.8%),BDE47(26.4%),and BDE99(16.8%).The present study compared the congener patterns of the sedimentary PBDEs with those of commercial products.The results indicated the possible use of penta-BDE in the Yangtze River Basin in a wide range or the fractionation and transformation of PBDE congeners during their long-range transport.