Distribution, Source, and Ecological Risk Evaluation of the PAHs and PCBs in the Sediments from Sanya River

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), two typical persistent organic pollutants, are the research focus due to their mutagenesis, carcinogenesis, teratogenesis, and bioaccumulation. The content distribution and residual characteristics of PAHs and PCBs were investigated in the sediments from the Sanya River. Source apportionment was further explored based on the analysis of the spatial distribution, and the ecological risk evaluation was carried out with the sediment quality criteria and standards. The results indicate that the content of ΣPAHs and ΣPCBs in the sediment range from 265.00 μg·kg-1 to 6735.00 μg·kg-1 and 1.75 μg·kg-1 to 92.75 μg·kg-1, with relatively high contents in the east and west river upstream, respectively, which had a strong correlation with the industrial structure and river movement of the study area. The composition and source apportionment demonstrate that PAHs originated mostly from the combustion of petroleum with low PAHs, and haxa-CB and hepta-CB are the predominant PCBs congeners, primarily resulting from the migration of PCBs in the capacitor. The ecological risk evaluation demonstrates that the biotoxic effect of the PAHs is not obvious, with a low ecological risk. However, several PAHs monomers exceeded the standard significantly in some sampling sites, which should be of concern due to its serious threat of exposure to organisms. The probability of a biotoxic effect of PCBs is 10%-50%, which occasionally produces a negative ecological effect.