[Contamination Levels and Exposure Risk via Drinking Water from Perfluoroalkyl Acids in Seven Major Drainage Basins of China].

To study the perfluoroalkyl acid (PFAAs) contamination in seven major drainage basins of China and the exposure risk to resident populations via drinking water sourced from these basins, a risk assessment model of the US EPA and a scenario-based risk assessment method were applied to analyze the PFAA pollution characteristics and to evaluate the average daily dose and health risk to adults, adolescents, and children. In the intermediate-exposure scenario, results showed that the ∑PFAAs median for the seven major drainage basins was 14 ng·L-1, with perfluorooctanoic acid (PFOA), perfluorobutanoic acid (PFBA), and perfluorooctane sulfonic acid (PFOS) the main contaminants, and that the contamination levels were the highest in the Songliao River and Taihu Lake basins. In the high-exposure scenario, the discharge proportion of perfluoroalkyl carboxylic acids with ≤ 6 carbon chains among the ∑PFAAs was higher than that in the intermediate-exposure scenario. In addition, certain sections tended to be more polluted than others in the Yellow River and Yangtze River basins. Risk assessment showed that PFOA and PFOS exposure via drinking water posed no health risk to Chinese residents, and that the average daily ingestion of drinking water of Chinese adolescents was below the suggested amount.