Aerosolisation of new generation perfluoroalkyl ether carboxylic and sulfonic acids from aeration of contaminated aqueous solutions

There has been an industrial shift towards replacing legacy per- and polyfluoroalkyl substances (PFAS) with perfluoroalkyl ether carboxylic and sulfonic acids (PFECA and PFESA) including hexafluoropropylene oxide dimer acid (HFPO-DA), also known as GenX. These compounds have been detected in the atmosphere but their potential sources remain poorly understood.

In this study, aerosolisation of six PFECA and PFESA from PFAS-contaminated water at concentrations and pHs representative of industrial sewage was investigated. All studied PFECA and PFESA were observed in the aerosols from the aeration of PFAS-fortified water at pH 6, 7 and 8. The aerosolisation behaviour of PFECA and PFESA increased with the analyte's carbon chain length and was influenced by the PFAS functional groups and pH of the aerated solution. PFESA with sulfonic acid groups aerosolised more from the solutions than PFECA with carboxylic acid groups. The ability of new generation PFAS to transfer from contaminated waters and become airborne (aerosolise up to a mass fraction 30.4 ± 2.7 %) raises concerns due to their potential health and environmental impacts. Our findings indicate that industrial and water management processes involving aeration of water contaminated with PFECA and PFESA could serve as potential sources of new-generation atmospheric PFAS.