Distribution of polybrominated diphenyl ethers and HBCD in sediments of the Hunhe River in Northeast China.

Forty surface sediment samples from the Hunhe River in Northeast China were evaluated for contamination by polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). The results showed that decabromodiphenyl ether (BDE-209) was the predominant congener, accounting for >98 % of PBDEs in all sediment. The concentrations of BDE-209 and HBCD ranged from 3.96 to 327 ng/g dry weight and 0.05 to 25.8 ng/g dry weight, respectively, suggesting that BDE-209 was more widely applied in the study area. The mean concentrations of BDE-209 and HBCD in the downstream portion of the Hunhe River (BDE-209 148 ng/g dry weight and HBCD 3.74 ng/g dry weight) were found to be relatively higher than those in the upstream portion of the Hunhe River and the Dahuofang Reservoir, revealing an association with municipal sewage and industrial effluent received from the cities of Fushun and Shenyang. γ-HBCD was the most abundant diastereoisomer of all three analyzed HBCD isomers; however, marked elevations of α-HBCD were also found in most sediment samples. Surprisingly, the relative abundance (mean 38%) of α-HBCD in sediment from the upstream portion of the Hunhe River was significantly higher (p < 0.006, t test) than those in Dahuofang Reservoir (mean 24%). Moreover, the severe heavy metal contamination associated with the frequent mining activities in this region was tentatively suggested as being responsible for the increased levels of α-HBCD.