The source-specific health risk and biological effect assessment of PAHs in Mactra veneriformis from the Bohai Sea and Yellow Sea

Source-specific risk assessment has been widely used to analyze the source of pollution risk instead of pollutant content for more accurate control of pollution. However, due to limitations in data type, assessment of sourcespecific biological effect has not been reported, which is highly significant for organism protection. This study conducted a comprehensive assessment of the health risk and biological effect of polycyclic aromatic hydrocarbons (PAHs) bioaccumulated in the clam Mactra veneriformis from two typical bays in China. PAH levels ranged from 122.68 to 367.21 ng/g d.w. (dry weight), indicating a moderate level of pollution. Incremental lifetime cancer risk (ILCR) assessment revealed low cancer risks associated with clam consumption. However, the integrated biomarker response (IBR) analysis indicated higher biological stress in Laizhou Bay compared to Haizhou Bay. Positive matrix factorization (PMF) identified traffic emissions (post combustion products), coal combustion, petroleum products released without combustion, and biomass combustion as sources of PAHs. A novel approach that integrates partial least squares regression (PLSR) with IBR and PMF enable source-specific biological effect assessment possible, along with PMF-ILCR, the results showed traffic emissions as the primary source of health risks, while petroleum was the primary source of biological effects. This study emphasizes the importance of source-specific risk assessment for developing targeted pollution control strategies especially source-specific biological effect, highlighting that the priority of PAHs pollution source control for typical bays in the Bohai Sea and the Yellow Sea should be: Petroleum > Traffic > Coal > Biomass.