PHAHs in 14 principal river sediments from Hai River basin, China.

This study was undertaken to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from 14 principal rivers of the Hai River basin. The concentrations of 22 polybrominated biphenyl (PBB) congeners, 27 polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediments were measured using GC-MS/MS technique. The highest PBB levels were detected in sediments from River Daqing: PBB3, 10, 4, 15, 26, 31, and 49 were observed in the sediments. The highest concentrations of PBDEs were in River Tuhe (G.M.=2.10 ng g(-1) dw), and PBDE15 was the most predominant congener in the sediments from all of the rivers of this study, except for River Tuhe, which accounted for >13.5% of the total PBDEs in sediments. PBDE209 was detected in sediments from the Beijingpaiwu, Nanyun, Majia and Tuhe rivers, with observed values ranging from 0.06 to 0.13 ng g(-1) dw. PCBs had the highest concentrations in sediment samples collected from River Luan and River Daqing, with levels of 18.13 and 25.62 ng g(-1) dw, respectively. The most predominant PCB congener in these samples was PCB138, which accounted for about 24% of the sum of the seven indicator PCB congeners (PCB28, 52, 101, 118, 138, 153, and 180) measured in the two rivers. The measured levels of PHAHs were compared with recent results, reported in the literature, and the respective sediment quality guidelines recommended by USEPA. The levels of PHAHs in the present study were generally lower than respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwaters from other regions. This suggests that, in these rivers, toxic biological effects on aquatic biota-due to PHAH contamination of sediments-can be expected to be negligible. Thus, in terms of PHAHs, the sediments can be regarded as relatively uncontaminated.