Serum PFAS levels in UK firefighters

Per- and polyfluoroalkyl substances (PFAS) represent an emerging concern due to their persistence, bioaccumulation, and emerging associations with different cancers and other diseases. Biomonitoring studies worldwide report elevated PFAS serum concentrations in firefighters compared with other occupations and the general population. The aim of this study was to quantify PFAS serum concentration in current and former firefighters and a general population comparison group in the UK. PFAS serum concentrations were analysed in a total sample of 1224 participants, including 942 firefighters from eight Fire and Rescue Services (FRSs) and 282 individuals from the general population. PFAS concentrations varied across tested FRSs, with geometric mean serum levels for some analytes higher than those observed in the general population. These included PFHxS (4.1 times higher), PFOS sum (1.5 times higher) and PFHPS (about 1.6 times higher), compounds that have been historically associated with the use of aqueous film forming firefighting foams. Furthermore, four PFAS (8:2 FTS, FOSA, PFBS, and PFPeS) were detected exclusively in firefighter serum and not in the general population, of which three are commonly detected in firefighter turnout gear. Descriptively, PFAS geometric mean concentrations tended to be higher among older firefighters and those with longer service duration. The general population cohort, drawn from a region which has subsequently been found to have some of the UK's highest PFAS environmental contamination, showed relatively high baseline serum PFAS levels, suggesting the contribution of high background environmental exposure in this cohort. Reported data highlights the need for PFAS monitoring among firefighters, including evaluation of occupational exposure pathways, with attention to likely sources such as firefighting foam types and formulations; the type of chemicals applied to turnout gear; PPE use, frequency and type of decontamination. Further research should also include wider monitoring of the general population, including evaluation of likely sources and pathways of exposure.