Atmospheric Emission of Per- and Polyfluoroalkyl Substances (PFAS) from a Fluoropolymer Manufacturing Facility: Focus on Emerging PFAS and the Potential Contribution of Condensable PFAS on their Atmospheric Partitioning

Fluoropolymer manufacturing facility (FMF) has been regarded as a main source of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the atmosphere. In this study, suspect screening was performed to identify emerging PFAS in gas, particles, and dust both inside and outside a large FMF in China. A total of 74 emerging PFAS were tentatively identified with a confidence level of 3 or higher, 32 of which were reported in the environment for the first time. The semi-quantitative concentrations of the emerging PFAS, with perfluoroalkyl ether carboxylic acids (PFECAs) and Cl-PFECAs being predominant, accounted for 21-95% (mean: 46%) of the combined concentrations of emerging and legacy PFAS. Although the PFAS concentrations in the atmosphere decreased rapidly by more than 95% within 5 km, short-chain PFAS in PM_2.5 were transported farther, especially C4 and C5 perfluoroalkyl carboxylic acids, which decreased by 66% and 79% within 5 km, respectively. Emerging PFAS with an ionic terminal group are mainly distributed in the particle phase, while alcohol-related PFAS are found in the gas phase. The ratios of PFAS in the gas phase inside the FMF were much higher than those outside, which could be reasonably explained by the condensation of gaseous PFAS onto fine particles shortly after being emitted.