Parent and halogenated polycyclic aromatic hydrocarbons in seafood from South China and implications for human exposure.

This work extends previous studies on the occurrence of persistent halogenated compounds in consumer seafood from South China. Residual levels of 16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) and 9 halogenated PAHs (HPAHs) were determined in three kinds of seafood products collected from 11 coastal cities in South China from June to October 2005. The results indicated that PAH components were low but detectable in a large number of seafood samples under investigation. The benzo(a)pyrene (BaP)-like TEQ concentrations of HPAHs were higher than those of PAHs for all three kinds of seafood. The relative contributions of each seafood group to the total estimated daily intake of PAHs and HPAHs were also analyzed. Shellfish contributed the most to the total exposure for all subgroups, followed by shrimp. Overall, the excess cancer risks (ECRs) induced by HPAHs were much greater than the risks posed by PAHs. Both ECRs for PAHs and HPAHs were far below 10(-4), showing no significant cancer risk via seafood consumption for people in South China. Sensitivity analysis results show the oral cancer slope factor of BaP is the most influential variable that contributed most to the total variance of risk for all subgroups.