[Content analysis and assessment of polycyclic aromatic hydrocarbons in surface sediments from Beijiang River, China]

In the present study, 16 polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from Beijiang River in China were quantitatively determined by GC/MS. The concentration of PAHs varied from 38.2 to 6470 ng x g(-1) dry weight, with average 1071 ng x g(-1), which was in moderate level compared with other rivers in Pear River Basin. The PAHs distribution in Bejiang River was obviously affected by point source emissions. The high PAHs concentrations of 6470 ng x g(-1) and 4 470 ng x g(-1) were found at the outfalls of Shaoye and the Shakou town, respectively, where PAHs probably derived from local mining/smelting and related industrial actives. The ecological risk of surface sediment in Beijiang River was assessed with the methods of sediment quality guidelines (SQGs), sediment quality standards (SQSs) and contamination factors (CFs) . The result shows that the adverse biological toxicity effect might occasionally happen in more than half of sampling stations. By comparison with the background area, the contamination degrees of PAHs in 20 sampling stations were at very high level, which should arrest the local governments' attentions. The highest ecological risk areas occurred at the outfalls of Shaoye and the Shakou town in which the ecological risks derived from PAHs were within between probable effect level (PEL) and frequent effect level (FEL). The future research was suggested mainly focusing on the status of benthos, sources of pollutants and ways to control pollution in high-risk areas.