Horizontal and vertical distribution of polybrominated diphenyl ethers (PBDEs) in river sediment from a typical electrical equipment industrial area

Polybrominated diphenyl ethers (PBDEs) were determined in sediment collected from a river in a typical electrical equipment industrial area, Ronggui, Foshan. Eight samples were collected from river sediment. The results indicated that PBDEs were presented in all samples. Spatial trends showed that the concentrations of PBDEs in all sediment samples were ranged from 62 ng·g^-1 to 349 ng·g^-1, with an average of 178 ng·g^-1. The predominant congener was BDE-209 (90%-99%), which ranged from 56-337 ng·g^-1, with an average of 171 ng·g^-1. Some of congeners such as BDE-196, 197 and 203 may be were the degradation product of BDE-209.Vertically, the concentrations of PBDEs were increased with the depth, whereas the concentrations were 147 ng·g^-1 in layer 0-10 cm and 260 ng·g^-1 in layer 30-40 cm, respectively. Distribution profile of PBDEs in vertical direction was similar in different depths. The commercial deca-BDE (94%), which contained BDE-209, 208, 207 and 206, was the dominate pollutant with minor contributions from penta-and octa-BDEs. The results suggested that this area was polluted by PBDEs and BDE-209 was the most dominate congener, which is related with the manufacturing activities for electrical equipment..