Ionic per- and polyfluoroalkyl substances in inhalable aerosols from wastewater treatment processes: Spatiotemporal...

Per- and polyfluoroalkyl substances (PFAS) can be aerosolized from wastewater treatment plants (WWTPs) into the atmosphere. However, the spatiotemporal distributions, dispersion characteristics, influencing factors, and risks of PFAS in fine particulate matter (PM_2.5) from WWTPs remain largely unclear. Herein, typical PFAS in PM_2.5 and wastewater were detected across seasons and treatment units. The fine grid filtration unit and summer were identified as the primary emission unit and season for PM_2.5-borne PFAS, respectively. Among the detected PFAS in WWTP-PM_2.5, perfluorooctanoic acid occurred at the greatest level. Higher total concentrations and species of PM_2.5-borne PFAS were detected from WWTP and downwind than from upwind. Wastewater was the principal origin of PFAS in WWTP-PM_2.5, with a contribution of nearly 50.00%. The estimated emission of the studied target PFAS reached up to 47.00 mg/d, with a dispersion distance exceeding 40 km. Inhalation was the dominant exposure pathway, males were exposed to slightly higher risks than females within the plant boundary, and the exposure threats for children exceeded those for adults outside the boundary. Wastewater-borne PFAS were the primary determinants shaping PFAS in WWTP-PM_2.5. These data highlight the aerosolization and risks of PFAS from WWTPs to air, thus the need for targeted control strategies.