Exposure to Perfluoroalkyl Substances in a Cohort of Women Firefighters and Office Workers in San Francisco

Abstract

Studies of firefighters have shown increased exposures to carcinogenic compounds and elevated rates of certain cancers compared to the general population, yet this research has focused almost exclusively on men. To address this gap, the Women Firefighters Biomonitoring Collaborative created a biological sample archive and analyzed levels of perfluoroalkyl substances (PFAS) among women firefighters (N = 86) and office workers (N = 84) in San Francisco. Serum samples were collected and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure and compare PFAS levels between firefighters and office workers. 7 of 12 PFAS congeners were detected in the least 70% of the study population, and 4 congeners were detected in 100% of participants. In regression models comparing PFAS levels by occupation and adjusting for potential confounders, firefighters had higher geometric mean concentrations of PFAS compared to office workers PFHxS (2.22 (95% CI = 1.55, 3.18)), PFUnDA (1.83 (95% CI = 0.97, 3.45)), and PFNA (1.26 (95% CI = 1.01, 1.58)). Among firefighters, occupational position predicted exposure-firefighters and officers had higher PFNA, PFOA, PFDA, and PFUnDA levels compared to drivers. Women firefighters are exposed to higher levels of some PFAS compared to office workers, suggesting that some of these exposures may be occupationally related.

Figure 1

Comparison of geometric mean (GM) and 95% confidence intervals (CI) of PFAS levels measured in WFBC firefighters and office workers (2014–15) with adult women in NHANES (2013–14) and male firefighters in the FOX study (2010–11). Figure footnote: Figure shows GM and 95% CI for those PFAS with detection frequencies of at least 70% among WFBC participants. PFBS had low DF for FOX (6.9%) and NHANES (0.7%); therefore, we plotted the LOD, represented by horizontal green lines, in lieu of GM and 95% CI. We replaced levels below the LOD with LOD/√2 and applied the LOD respective to each study population. Tests of statistical significance for differences between WFBC groups is shown in Table 4.