Distribution and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Water Bodies in Seven Basins of China

Abstract

The concentrations and spatial distribution characteristics of 16 US EPA priority Polycyclic Aromatic Hydrocarbons (PAHs) in water bodies in seven basins in China were systematically analyzed and summarized. The acute ecological risks of 8 PAHs to aquatic organisms were evaluated by means of species sensitivity distribution (SSD). The joint acute ecological risks of ΣPAH8 to aquatic organisms were evaluated by concentration addition model and response addition model. The health risks of PAHs ingestion were estimated by hazard quotients. The results showed that the 2-, 3-, and 4 ringed-PAHs had higher-than-average concentrations in the water bodies from the seven basins, and the mean concentration of ΣPAH16 was 2596.25 ng·L-1, which is higher than in most foreign water bodies. The composition characteristics and sources of PAHs in water bodies of China and other countries were similar. The pollution of ΣPAH16 in northern water bodies was more serious compared with that of southern water bodies. The potentially affected fraction (PAF) values of naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene, and anthracene to aquatic organisms in the seven basins were less than 4%. Except for the Haihe River and Yangtze River basins, the PAF values of benzo (a) pyrene to aquatic organisms exceeded 5%, which indicates that benzo (a) pyrene had high acute ecological risks to aquatic organisms. The concentration addition model was not suitable for water ecological risk assessments of PAHs. The results of risk assessments based on response addition model showed that except for the Haihe River, the multisubstance PAF (msPAF) values of ΣPAH8 to aquatic organisms in other basins exceeded 5%, which indicates that ΣPAH8 constitutes high joint acute ecological risks to aquatic organisms. The health risks through ingestion of carcinogenic PAHs from water bodies of the seven basins were at 10-5 level, which is higher than the baseline value of acceptable risk (10-6) from the US EPA. The health risks through the ingestion of non-carcinogenic PAHs were at 10-9 level, which is far lower than the baseline value of acceptable risk. The results indicate that there are potential carcinogenic risks to human health through ingestion of PAHs from seven basins in China.