PER- AND POLYFLUOROALKYL SUBSTANCES (PFAS) IN RESIDENTIAL AIR CONDITIONER CONDENSATE

Many per- and polyfluoroalkyl substances (PFAS) are water-soluble which suggests that PFAS in indoor air may partition into air conditioning (AC) condensate. As part of the Indoor PFAS Assessment (IPA) Campaign, we measured 15 anionic PFAS species in AC condensate from 9 homes during July and August 2021. The sum of measured PFAS was 14.7 ± 13.3 ng/L (mean ± one standard deviation), across homes. Perfluorohexanoic acid (PFHxA; 4.35 ng/L), perfluorooctanoic acid (PFOA; 2.09 ng/L), and perfluorooctanesulfonic acid (PFOS; 3.58 ng/L) were the largest contributors to the mean. On average, the rate of condensate water removal was 2.61 L/hr-home during air conditioner operation, suggesting that the total flux of PFAS exceeds 32.6 micrograms of PFAS per home over one cooling season. We conclude that AC operation is an effective sink for PFAS from indoor air and contributes to surface and groundwater PFAS contamination in urban areas.