UC Berkeley

Abstract: Background: Studies in male firefighters have demonstrated increased exposures to carcinogenic compounds and increased rates of certain cancers compared to the general population. Many chemicals related to these occupational exposures have been associated with breast tumor development in animal and human studies, yet, there have been no studies on women firefighters due to their low numbers in most fire departments. To address this data gap, the Women Firefighters Biomonitoring Collaborative (WFBC) created a biological sample archive and analyzed levels of perfluoroalkyl substances (PFAS) among women firefighters and office workers in San Francisco. Methods: Active duty women firefighters (n=86) and office workers (n=84) were recruited from the San Francisco Fire Department and the City and County of San Francisco, respectively. 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. For PFAS congeners detected in at least 70% of our study population, we examined differences in serum PFAS levels controlling for dietary, demographic and other confounders. Among firefighters, we assessed associations between occupational activities and PFAS levels. Results: Eight of 12 PFAS congeners were detected at levels above the limit of detection and seven were detected in at least 70% of the study population. Four PFAS were detected in all study participants (PFNA, PFOA, PFOS, PFHxS). In regression models comparing PFAS levels by occupation and adjusting for potential confounders, firefighters had higher geometric mean (GM) concentrations of PFAS compared to office workers: 2.39 (95%CI = 1.64,3.48), 2.32 (95% CI = 1.17,4.62) and 1.26 (95% CI = 0.99, 1.59) times higher for PFHxS, PFUnDA and PFNA, respectively. In analyses limited to firefighters, PFAS levels varied by assigned position in the fire department—firefighters and officers had higher PFNA, PFOA, PFDA, and PFUnDA compared to drivers. Additionally, firefighters who reported having used firefighting foam had higher concentrations of PFOA compared firefighters who reported never having used foam. Conclusion: Our study found ubiquitous exposures to PFAS among WFBC participants, with women firefighters exposed to higher levels of some PFAS compared to office workers, suggesting that some of these exposures may be occupationally related.