Serum PFAS in Aircraft Rescue and Firefighting (ARFF) Firefighters From Six U.S. Airport Fire Departments

INTRODUCTION: Use of aqueous film-forming foam (AFFF) is a source of exposure to per- and polyfluoroalkyl substances (PFAS) for firefighters working in aircraft rescue and firefighting (ARFF) settings. However, data characterizing the association between serum PFAS concentrations and exposure risk factors for ARFF firefighters are limited. METHODS: In this cross-sectional study, ARFF firefighters (N = 193) from six U.S. commercial airports provided serum for quantification of nine PFAS and completed a survey in 2019-2020. A drinking water sample from each fire station was also analyzed for 29 PFAS. Serum PFAS concentrations were compared with demographically-similar participants from the National Health and Nutrition Examination Survey (NHANES) 2017-March 2020. Multivariable linear regression was used to identify factors associated with serum PFAS concentrations. RESULTS: Geometric mean serum concentrations of perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS) branched isomers, and perfluoroundecanoic acid (PFUnDA) were statistically higher in ARFF firefighters compared with NHANES participants. PFAS were detected in tap water at three fire departments, but only one department was characterized by detection of select PFAS (perfluorooctanoic acid (PFOA), PFOS, and PFHxS) in both water and serum. Past employment, detection of PFAS in drinking water, and age were positively associated with select PFAS concentrations; a recent change in workplace AFFF behavior or practice, female sex, and Black race exhibited inverse associations. CONCLUSIONS: Participants reporting changes in workplace behavior, policy, or practice had lower summed PFAS concentrations, suggesting these measures may help reduce exposure. Continued research is needed to evaluate exposure reduction strategies for firefighters, particularly those working in ARFF settings.