Prevalence and predictors of per- and polyfluoroalkyl substances (PFAS) serum levels among US volunteer firefighters

Abstract

BACKGROUND AND AIM: Per- and polyfluoroalkyl substances (PFAS) are synthetic persistent compounds of health concern. Firefighters may be exposed to PFAS through firefighting foams, combustion products, and equipment/gear. Studies have shown elevated PFAS levels in paid firefighters. Few studies include volunteer firefighters, who comprise 67% of US firefighters. We assessed seroprevalence and predictors of PFAS levels among US volunteer firefighters enrolled in the Firefighter Cancer Assessment and Prevention Study (CAPS), a research partner of the Fire Fighter Cancer Cohort Study (FFCCS). METHODS: Consenting firefighters (n=413) enrolled from 34 volunteer departments in four US states - Connecticut (CT), Maine (ME), Maryland (MD), and New Jersey (NJ). Participants completed a survey and provided blood samples, analyzed for PFAS by online solid phase extraction unit and HPLC-MS/MS instrumentation. We calculated prevalence and geometric means by location (a single NJ department (NJ-Dept1), NJ-Other, CT&MD, ME). For select PFAS (prevalence ≥75%), we assessed associations between PFAS (log-transformed) and age, firefighting years, monthly responses, and location in single-PFAS multivariate models. RESULTS: Most participants were non-Hispanic White (91%), male (92%), with an average age of 45.2 years (sd 15.4) and 20.2 years (sd 15.7) of firefighting. Serum levels of the six PFAS were similar between locations, except perfluorodecanoic acid (PFDeA) was significantly higher in NJ-Dept1 than elsewhere (0.25ug/L, vs 0.08, 0.09, 0.08; p<0.0001) and perfluorooctanoic acid (PFOA) was higher in NJ-Other than elsewhere (2.35ug/L vs 1.96, 1.23, 1.29; p<0.0001). In multivariate analysis, PFOA and PFDeA were positively associated with age (p=0.006, 0.0736, respectively) and location (p<0.0001 (for all locations, ref = NJ-Dept1)), controlling for firefighting years and monthly responses. CONCLUSIONS: We observed spatial differences in volunteer firefighters’ serum PFOA and PFDeA levels. Further research is needed to better understand sources of PFAS among volunteer firefighters, including their primary occupations and community exposures. KEYWORDS: PFAS, firefighters, volunteers