Occurrence of Ultrashort-Chain PFASs in Australian Environmental Water Samples

Ultrashort-chain per- and polyfluoroalkyl substances (PFASs) are an emerging class of contaminants that remain underexplored in environmental research. This study examines their distribution in Australian drinking tap water, environmental waters, and wastewaters (n = 63) using nontarget analysis via high-resolution mass spectrometry. Thirteen ultrashort-chain PFASs were identified, including novel compounds such as perfluoroalkane sulfinate (PFPSi), hydrogen-substituted perfluoroalkyl carboxylate (H-PFCA), chloro-perfluoroalkanesulfonate (Cl-PFSA), and bis-perfluoroalkyl sulfonamide (bis-FASIs). Perfluoropropanesulfonic acid (PFPrS) was the most prevalent, detected in 83% of surface, groundwater, and wastewater samples, and in 67% of tap water samples from major Australian cities. Concentrations of PFPrS and perfluoroethanesulfonic acid (PFEtS) ranged from <0.02 to 8000 ng/L. Ultrashort-chain perfluoroalkane sulfonamides (FASAs) and perfluoroalkane sulfates (PFA-OS) were predominantly found in wastewater. These findings highlight the widespread presence of ultrashort-chain PFASs in Australian water systems and underscore the need for ongoing monitoring and research due to their potential ecological and human health impacts. This study provides essential baseline data that could inform future regulatory measures and environmental management strategies.