Abstract
Abstract Introduction Firefighters are occupationally exposed to per- and polyfluoroalkyl substances (PFAS) in Aqueous Film Forming Foam (AFFF), a fire suppressant and in the moisture barrier of their safety gear. Certain PFAS are increasingly linked to metabolic toxicity and carcinogenicity. We examine changes in metabolic pathways associated with exposure to serum PFAS in firefighters. Methods Firefighters from two U.S. fire departments consented to the study, completed a health survey and provided a blood sample. Seven distinct PFASs were quantified using a liquid chromatography-isotope dilution-tandem mass spectrometry approach. Global metabolomic profiles were determined across three experimental groups (i.e., male, female and airport firefighters). ANCOVA contrasts were used to identify biochemicals that differed significantly between groups. Results Among 50 firefighters, 30.0% were female, 66.0% White/non-Hispanic, and 53.1% overweight, with group average age, 41.8 years ±9.9 (standard deviation). Thirty percent worked as airport firefighters, while 70.0% as structural/career firefighters. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) were higher in airport (ratio fold change [FC]:2.17 and 3.16;p≤0.05) and male firefighters (FC:2.22 and 2.81;p≤0.05) compared to females. Lactate levels were higher in airport firefighters (FC:1.44;p≤0.05) compared to male/female firefighters, while ceramides (FC:0.58 and 0.72;p≤0.05) and sphingomyelins (FC:0.76 and 0.78;p≤0.05) were lower in airport and male firefighters versus females. Eicosanoids (FC:2.37;p≤0.05), fibrinopeptide products FC:2.21;p≤0.05), glutathione related antioxidant metabolites (FC:2.66;p≤0.05) were higher in airport versus female/male firefighters. Discussion and conclusion Several observed differences were more robust in airport firefighters suggesting greater metabolic differences in these firefighters compared to non-airport firefighters.