Polycyclic aromatic hydrocarbons (PAHs) are a group of common organic contaminants. While halogenated PAHs (HPAHs)are a group of contaminants comprising of PAHs and one or more halogen atoms attached to the aromatic skeleton, which show more toxic than their corresponding parent PAHs. Due to their properties of bioaccumulation and eco-toxicity, as well as the impacts on human health, human exposure to PAHs and HPAHs is always an extensive concerned environmental issue. 

Seafood studied in the present study （Image by IGCAS）

Seafood is the main source for people to get protein. In the acquisition of this nutrient, a certain amount of organic contaminants, including PAHs and HPAHs, are also intake simultaneously. Coastal area of Guangzhou is the main seafood producing and export area in China. Research on the residues and human exposure of PAHs and HPAHs in seafood products in this area is of importance to the health risk assessment for the coastal residents as well as global concerns.

Associate Professor GUO Jianyang from Institute of Geochemistry, Chinese Academy of Sciences(IGCAS) and his collaborator conducted a systemic survey on residues and human exposure of PAHs and HPAHs in seafood products from coastal area of Guangzhou.

The team examined the seafood samples collected from 11 coastal cities in South China. They found that PAH components were generally low but detectable in numerous samples while the benzo(a)pyrene (BaP)-like TEQ concentrations of HPAHs were higher than that of PAHs for all kinds of samples. 

Among these seafood products, Shellfish was found to contribute the most to the total exposure for all subgroups, followed by shrimp. Sensitivity analysis revealed that the oral cancer slope factor of BaP was the most influential variable that contributed most to the total variance of risk for all subgroups. Risk assessment against various standards suggested that both PAHs and HPAHs in the seafood samples under investigation might pose health threat to the local residents.

“Therefore, identifying the sources of PAHs and HPAHs in seafood products and conducting a continual monitoring is urgently needed to mitigate effectively the impact of PAHs, particularly HPAHs, on human health and the ecological environment,” concluded the researchers.

This work is financially supported by the National Natural Science Foundation of China (No.41071303 and 40973087), and has published in Journal of Agriculture and Food Chemistry (HG Ni, JY Guo. 2013. Parent and halogenated PAHs in seafood from South China: implications for human exposure. Journal of Agriculture and Food Chemistry. 2013, 61 (8): 2013-2018). 

（By GUO Jianyang）