Neutral and ionic PFAS in coastal Antarctica: Global context, diagnostic ratios, and implications for long-range atmospheric transport.

Per- and polyfluoroalkyl substances (PFAS) have been frequently detected in polar environments despite the absence of substantial local emissions, raising concerns about long-range atmospheric transport (LRAT) and precursor-driven inputs to remote regions. This study characterized the occurrence and distribution of neutral (nPFAS) and ionic PFAS (iPFAS) in air, soil, and moss collected near King Sejong Station, Antarctica. Year-long passive air samples revealed the predominance of volatile fluorotelomer alcohols (FTOHs) in atmosphere, accompanied by short-chain perfluorobutanoic acid (PFBA) and perfluorobutanesulfonate (PFBS). Spatial variations in FTOH composition showed modest site-specific differences potentially associated with air-mass transport and mixing, while strong correlations between FTOHs and their transformation products indicated active atmospheric oxidation. PFBA was the most consistently observed PFAS in air, soil, and moss, reflecting its high mobility and ubiquity in Antarctica. Field-derived soil-air partitioning coefficients (KSA) further suggested that short-chain PFAS may be introduced through multiple pathways, including direct atmospheric transport and soil-associated precursor degradation. These findings situate Antarctic PFAS occurrence within wider global emission and transport dynamics. Sustained atmospheric monitoring will be critical for assessing how evolving PFAS usage influences long-range transport to the Antarctic environment.