A study including researchers from the University of Arizona Health Sciences and published in the Journal of Exposure Science & Environmental Epidemiology found that firefighters had higher concentrations of certain per- and polyfluoroalkyl substances, or PFAS, and health care workers had moderate elevations of PFAS in their blood with significantly higher odds of two specific PFAS when compared with other essential workers.
“Our study reinforces previous research showing elevated PFAS levels among firefighters and suggests that health care workers may have unique sources of PFAS exposure as well,” said senior author Kate Ellingson, PhD, an associate professor at the Mel and Enid Zuckerman College of Public Health. “Our findings underscore the need to understand occupational exposure pathways for PFAS among different types of workers.”
PFAS are a class of synthetic chemicals used in a wide range of products because of their stain-, water- and flame-resistant properties. PFAS do not degrade easily over time and are highly stable in the environment, making them capable of contaminating our food, water and material products.
The study sought to assess the differences in blood concentrations of PFAS among a range of frontline workers in Arizona. It is the first to evaluate PFAS levels in individuals working in health care.
Among health care workers, researchers found moderate elevations of certain PFAS (PFHpS and PFUnA), along with notably higher odds of detecting Sb-PFOA and PFDoA compared with individuals in other professions.
Firefighters had the highest concentrations of PFAS in their blood samples, specifically concentrations of PFHxS, Sm-PFOS, n-PFOS and PFHpS. This aligns with previous studies and implies distinct sources of occupational PFAS exposure remain for firefighters in Arizona.
PFAS serum levels in other essential workers declined 6% to 17% per year over the three-year study period; however, there were still notable levels of PFAS in their blood samples.
PFAS data were available for 1,960 study participants, including 280 firefighters and 787 health care workers and 734 other essential workers.
“Almost all adults in the U.S. have detectable levels of certain PFAS, and people in occupations with more frequent exposure to PFAS-containing materials have been shown to exhibit higher serum concentrations of some PFAS,” said co-author Jeff Burgess, MD, MPH, a professor, the director of the Center for Firefighter Health Collaborative Research at the Zuckerman College of Public Health and a BIO5 Institute member. “Research into occupational exposure to PFAS is vital to reduce the health risks associated with PFAS, including but not limited to increases in rates of certain cancers, increases in cholesterol levels, lower antibody response to certain immunizations, and increased rates of certain adverse reproductive outcomes.”
Firefighters are one of the more widely studied populations because of their frequent contact with sources of PFAS, including the protective gear worn while fighting fires and the foam used to extinguish fires. Other frontline workers, such as health care workers, are not as widely studied.
“To date, PFAS exposure in health care settings has not been widely studied, and the potential sources of exposure remain unclear,” Ellingson said, noting that single-use surgical masks, surgical gowns and X-ray film could be potential sources of PFAS exposure. “Therefore, it’s important to further examine specific exposure routes and health consequences for firefighters and health care workers.”
The study used data collected from July 2020 through April 2023 through the Arizona Healthcare, Emergency Response, and Other Essential Worker Surveillance Study, or AZ HEROES, at the U of A Health Sciences.
In addition to Ellingson and Burgess, co-authors from the University of Arizona Health Sciences include graduate student James Hollister, research manager Shawn Beitel, former graduate student Ferris Ramadan, Karen Lutrick, PhD, associate professor of family and community medicine at the College of Medicine — Tucson, and Julia Fisher, PhD, assistant research professor at the BIO5 Institute. Others who contributed to the research include first author Cedar Mitchell, PhD, an epidemiology field officer for the Centers for Disease Control and Prevention who previously served as an epidemic intelligence service officer with the Pima County Health Department, and Shawn O’Leary and Zhihua Tina Fan, PhD, both of the New Jersey Department of Health.
This research was supported by the Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases under award no. 75D30120C08379 and the National Institute of Environmental Health Sciences, a division of the National Institutes of Health, under award nos. 5R21ES032680 and R21ES033598.
