Perfluorinated compounds (PFCs) in the natural water systems of China: A meta analysis and risk assessment

Perfluorinated compounds (PFCs) are widely distributed in aquatic environments. However, there are few reports on the comprehensive analysis and assessment of the distribution and hazard of PFCs in China's natural water systems. Therefore, to bridge the research gap and deeply understand the current situation of PFCs in China's natural water systems, this study systematically meta-analyzed PFCs data from 2013 to 2023. The results revealed that the highest median concentrations of perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA), which were 41.31 and 12.79 ng/L in surface water and 47.81 and 12.91 ng/L in groundwater, respectively, were reported in natural water systems in China. Over time, the proportion of long-chain PFCs in surface and groundwater in China has become less than short-chain PFCs, which may have been influenced by the implementation of the government's environmental protection policies, the fulfillment of the Stockholm Convention, and product substitution. Additionally, PFCs in China's natural water systems are distributed mainly in eastern and coastal regions. The risk assessment revealed that the PFCs risks in some tributaries of some river basins are relatively high. For example, the risk quotient (RQ) values of PFCs in Xiaoqing River in the Yellow River Basin, Daling River in the Liaohe River Basin, and Tangxun Lake in the Yangtze River Basin ranged from 0.26 to 3337, which indicate medium- to high-risk levels requiring enhanced control measures for PFCs. The findings of this research offer a theoretical reference for the management and risk assessment of PFCs in the Chinese water environment.