Characterization and risk prioritization of PFAS via nontarget screening in soil and maize near a fluoropolymer...

Increasing per- and polyfluoroalkyl substances (PFAS) contaminations near the fluoropolymer manufacturing facility (FMF) pose significant concerns, demanding innovative approaches to elucidate their environmental fate and risks. In this study, 55 PFAS of 15 classes were identified in soil and maize near a FMF in China using a combination of target, suspect, and nontarget screening. Perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl ether carboxylic acids (PFECAs), and Cl-PFECAs were the dominant PFAS. The similar spatial distribution of PFAS in soil and maize, with higher PFAS concentrations consistently observed downwind of the FMF, was related to atmospheric deposition. Notably, short-chain PFAS (e.g., C4 H-PFCA, C3 PFECA, and PFBA) showed a stronger bioaccumulation potential in maize than long-chain PFAS across spatial scales near the FMF. Given the industrial trend toward shorter-chain PFAS, their significant accumulation suggested an unanticipated high PFAS exposure level in plants. Based on regional screening levels (RSLs) of soil, PFOA concentrations exceeded the ceiling limit of resident soil protection in the entire study area. Concurrently, the concentrations of PFDA and HFPO-TrA in the soil of some areas in the northwest part of the FMF also exceed the screening values. To refine the risk assessment of PFAS, a multicriteria screening and ranking approach was developed to effectively integrate the environmental occurrence, ecological risks, and health effects. Fourteen PFAS were recommended for high-priority PFAS in soil, such as four Cl-PFECAs, PFOS, two Cl-PFESAs, and PFOA. Overall, this study provided a practical solution for the identification and risk assessment of PFAS in industrially impacted terrestrial environments.