Release of per- and polyfluoroalkyl substances (PFAS) from a waste management facility fire to an urban creek

Abstract

This study examined the release of per- and poly fluoroalkyl substances (PFAS) into an urban freshwater stream and sediments due to a large-scale industrial fire in Melbourne, Australia. The fire occurred at an industrial warehouse which was illegally storing excessive amounts of unknown chemicals and industrial waste. The runoff of the waste and used firefighting foam was contained in the adjacent freshwater creeks. The concentration of 50 PFAS in freshwater samples and 16 PFAS in sediment samples were determined by HPLC-MS/MS. Of the fifty targeted PFAS in the freshwater samples, fluorotelomer sulfonates including (6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB or 6:2 FTSA-PrB; CAS NO:34455-29-3), Perfluorocarboxylates (PFCAs: C4-C12), Perfluoroalkane sulfonates (PFSAs: C4-C8) and perfluoroalkanesulfonyl fluorides including perfluorobutane sulfonamide (FBSA) were the most elevated PFAS. There were clear differences in ∑50PFAS mean concentrations detected on the day of the fire (3843 ng/L) relative to one month post fire (352 ng/L), indicating the effect of the fire on freshwater system. The concentration of ∑50PFAS at the point source was 3400 ± 324 ng/L on the day of the ignition and decreased significantly to 93 ±14 ng/L in the second campaign. This is the first study to document 6:2 FTAB and perfluorohexane sulfonamide (FHxSA; CAS NO 41997-13-1), perfluoro-4-methoxybutanoic acid (PFMBA; CAS NO 863090-89-5), perfluoro-3-methoxypropanoic acid (PFMPA; CAS NO 377-73-1), Hexafluoropropylene oxide dimer acid (HFPO-DA; CAS NO 13252-13-6), Nonafluoro-3,6-dioxaheptanoic acid (NFDHA; CAS NO 151772-58-6) and Perfluoro(2-ethoxyethane) sulfonic acid (PFEESA CAS NO 113507-82-7) in Australian surface waters. Only three PFAS were detected in the sediment samples which collected from five sites in the second campaign which could be negligible based on the detection. In the meanwhile, the concentration of PFAS were also compared to the available guideline values in Australia for freshwater, recreational water, and sediments. The analysed water samples indicated that PFOS contamination level might have a short-term risk to the aquatic organisms. Further monitoring is in need to evaluate the contamination and the long-term risk in freshwater and sediments in the region.