PHAHs in large reservoir sediments from Hebei and Hubei provinces, China

This study was undertaken to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from large reservoirs located in Hebei and Hubei provinces in China. The concentrations of 21 polybrominated biphenyl (PBB) congeners, seven polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediments were measured using the GC-MS/MS technique. Low-brominated PBBs (including 1, 3, 4, 10, 30, 31 and 53) were the most abundant PBB congeners and PBDEs 28, 47 and 99 were the most prevalent PBDE congeners in these samples. Among the three subfamilies of PHAHs, PCBs were the most predominant pollutants detected. The measured levels of PHAHs were compared with recent results reported in the literature and their respective sediment quality guidelines recommended by USEPA. The levels of PHAHs in the present study were generally lower than their respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwaters from other regions. This suggests that, in these reservoirs, 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 in the selected reservoirs are relatively uncontaminated.