Risk prioritization and experimental validation of per- and polyfluoroalkyl substances (PFAS) in Chaohu Lake: based on nontarget and target analyses

Pollution caused by per- and polyfluoroalkyl substances (PFAS) in surface water has become a global health concern. Nevertheless, due to the continuous production of emerging PFAS, the pollution levels and hazards of several precursors and their metabolites have not been evaluated. In this study, Chaohu Lake was selected as a representative freshwater lake to obtain a deeper understanding of the profiles of emerging PFAS in surface water. Nontarget screening tentatively identified 49 PFAS with a confidence level of ≥L3, which included 12 legacy PFAS and 37 emerging PFAS. Based on a target analysis of 57 PFAS, 18 PFAS were detected, with at least 10 PFAS detected in every water sample, indicating the widespread presence of PFAS in Chaohu Lake. Moreover, a risk-based PFAS priority model was used to prioritize the PFAS in Chaohu Lake. Remarkably, perfluoromethanesulfonic acid (PFMeS) exhibited the highest level of risk index among the intersection PFAS identified by the nontarget screening of Chaohu Lake water and human serum. For validation, the cytotoxicity of PFMeS was further evaluated in vitro. This study considerably expands our understanding of the occurrence, environmental risk, and cytotoxicity of PFAS in Chaohu Lake and also provides an experimentally validated basis for future research on novel contaminants in a water environment.