Concentrations and Estimated Daily Intake of Legacy and Emerging PFAS in the Milk of Women Residing in the Greater Cincinnati Area

BackgroundPer- and polyfluoroalkyl substances (PFAS) have been reported in human milk. However, prior U.S. studies have not included novel PFAS alternatives of emerging concern or infants Estimated Daily Intake (EDI) of PFAS. MethodsHuman milk was collected between 2019 and 2020 at 6 weeks after delivery from 100 Cincinnati, Ohio, nursing women participants in the IMPRINT study; 29 PFAS congeners were measured using ultrahigh performance liquid chromatography-mass spectrometry. We performed descriptive exposure analyses and assessed infants PFAS EDI from human milk. ResultsAll human milk samples contained PFAS. Of the 19 PFAS detected, 5 congeners were concurrently found in [≥] 50% of the samples. Legacy PFAS had the highest detection frequencies and concentrations: 97.7% for perfluorooctanesulfonic acid (PFOS) (median concentration: 14.5 ng/L) and 89.8% for perfluorooctanoic acid (PFOA) (median: 17.4 ng/L), 71.6% for perfluorohexanesulfonic acid (PFHxS) (median: 3.7 ng/L), and 70.0% for perfluorohexanoic acid (PFHxA) (median: 10.4 ng/L). An emerging PFAS, dodecafluoro-3H-4,8-dioxanonanoate (ADONA), was detected in 68.0% of samples (median: 3.5 ng/L). The PFAS with the highest EDI included PFOA (median: 8.6 ng), PFOS (median: 7.1 ng), and PFHxA (median: 5.8 ng). About 98% of samples had PFAS levels above the European Food Safety Authority (EFSA) tolerable weekly intake of 4.4 ng/kg body weight/week for the sum of PFOA, PFOS, PFHxS and perfluorononanoate (PFNA). ConclusionsHuman milk from women in Cincinnati, Ohio, contained both legacy and emerging PFAS and infants PFAS consumption through breastfeeding exceeded EFSA tolerable weekly intakes.