Korean Firefighters Show Higher Median PFOA Levels in Serum

Korean firefighters had a higher median serum concentration of perfluorooctanoic acid (PFOA) than members of the general population in a comparative study of per- and polyfluoroalkyl substances (PFAS). The median concentration was 6.60 ng/mL among firefighters and 3.84 ng/mL in the general-population group, a statistically significant difference according to a Mann–Whitney U test (p < 0.01). The researchers also identified differences in the composition of PFAS in the two groups, with PFOA contributing the largest share of total PFAS among firefighters and perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) more prominent in the general population.

The study assessed serum concentrations of seven PFAS in Korean firefighters and the general population to characterize exposure levels, compositional profiles, and relationships with demographic, occupational and lifestyle factors. Principal component analysis showed substantial overlap between the groups, indicating that the analysis did not cleanly separate them. Within that overlap, PFOA and selected long-chain perfluoroalkyl carboxylic acids contributed more strongly to variability among firefighters. The results therefore support a difference in the typical PFOA concentration and the mixture of compounds detected, rather than a complete separation between the groups. The available study summary does not report individual distributions, sample sizes or clinical outcomes.

Length of service was positively correlated with several PFAS in unadjusted analyses of firefighters. In the primary multivariable analyses, positive associations remained for perfluorononanoic acid (PFNA) and PFHxS after accounting for the study’s selected demographic, occupational and lifestyle variables. Those associations were attenuated in sensitivity analyses that used alternative covariate specifications, making their stability less certain. In the general population, selected relationships involving age, height, and time spent walking or strolling persisted after adjustment. These statistical associations do not establish that occupational tenure or the other measured factors caused the observed serum concentrations, and the summary reports no causal analysis.

The findings are limited to the populations, compounds and variables included in the study. They characterize measured serum exposure rather than demonstrating that any individual firefighter had elevated exposure, and they do not establish when exposure occurred or whether concentrations changed over a career. No health effects were evaluated in the reported results. The authors nevertheless concluded that the contrast between the groups, together with the occupational and other correlates identified within them, underscores the importance of considering occupational characteristics when assessing and managing PFAS exposure.

Subject of Research: Serum PFAS exposure and associated factors in Korean firefighters

Article Title: Assessment of per- and polyfluoroalkyl substances (PFAS) exposure in Korean firefighters by serum analysis

Article References: Choi, S., & Oh, J.-E. (2026). Assessment of per- and polyfluoroalkyl substances (PFAS) exposure in Korean firefighters by serum analysis. Environmental Geochemistry and Health, 48(16), Article 647. https://doi.org/10.1007/s10653-026-03547-4

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03547-4

Keywords: PFAS, PFOA, firefighters, serum analysis, South Korea, occupational exposure, PFOS, PFHxS, PFNA, environmental health, Assessment, per-