Quantitative evaluation of carcinogenic and non-carcinogenic potential for PAHs in coastal wetland soils of China

The levels, sources and health risks for PAHs collected at the national scale in China were discussed in the study. The total concentrations of 16 PAHs in nine coastal wetland soils ranged from 10.8 to 4870 ng g−1. The sources of PAHs were apportioned by PCA, and both the carcinogenic and non-carcinogenic risks were quantitatively calculated with Monte Carlo simulation. A sensitivity analysis was performed to determine the greatest effect of input variables on the risk assessment. The results revealed that 16 PAHs mainly originated from coal combustion, natural gas combustion, diesel emission, and petrogenic source. The carcinogenic risk and non-carcinogenic risk for nine coastal wetlands were below the risk threshold value (10−6 for carcinogenic risk, and 1 for non-carcinogenic risk, respectively), indicating no potential adverse health effects developed. Ingestion and dermal contact were the major exposure routes for PAHs risks. Exposure duration and PAHs concentration contributed most to the total risks uncertainty. This study is the first attempt to provide information on health risk of PAHs in wetland soils from a national perspective. The findings support the feasibility of development and evaluation of an implementation strategy for PAHs risks management in coastal wetland soils.