Study of exposure to PFAS compounds among frontline workers shows increased concentrations among firefighters and healthcare workers
Recently published results from a research study by Cedar Mitchell, PhD, Kate Ellingson, PhD, Jeff Burgess, MD, MPH, MS, and others, sought to assess the differences in blood concentrations of per- and polyfluoroalkyl substances (PFAS) among a range of frontline workers in Arizona. The findings reveal that, compared to other essential workers, firefighters have higher concentrations of certain PFAS, and healthcare workers have more frequent detection of other PFAS, in their blood.
This research highlights the concerns of firefighters and healthcare workers, who may be exposed to unique sources of PFAS. Further, this research underscores the need to understand occupational exposure pathways and the effects of PFAS among different types of workers. Dr. Mitchell led this analysis as a CDC Epidemic Intelligence Service officer with Pima County Health Department, working in collaboration with the AZ HEROES study at the Zuckerman College of Public Health.
What are per- and polyfluoroalkyl substances?
Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals used in a wide range of products and materials because of their stain-resistant, water-resistant, and flame-resistant properties. PFAS do not degrade easily over time due to their highly fluorinated aliphatic chemistry, meaning that they contain at least one carbon atom bound to three fluorine atoms, which makes PFAS compounds highly stable in the environment and capable of contaminating our food, water, and material products. When ingested, PFAS compounds remain in the body for long periods and lead to increased risk of kidney and testicular cancers, increases in cholesterol levels, lower response to certain immunizations, and other health risks.
What is the relationship between PFAS and essential workers?
Many workers are exposed to PFAS on the job, but firefighters are one of the more widely studied populations affected due to their frequent contact with sources of PFAS. One possible source of exposure comes from their “turnout gear,” which is the protective clothing worn during fires. The jackets, pants, gloves, and boots worn by firefighters have moisture barriers that contain PFAS compounds which increase thermal stability and are resistant to oil and water.
Another source of exposure for firefighters comes from aqueous film forming foam (AFFF) used to extinguish liquid flammable fires. These foams were created in the 1960s and have been widely used since the 1970s. Starting in 2015, manufacturers have been transitioning to modern fluorotelomer AFFFs, which are considered less toxic. However, the older “legacy foams” have a long shelf life and may still be in stock at any given fire department today. Drinking water at some fire stations also contains PFAS.
These various sources of PFAS exposure for firefighters highlight the need to examine the health consequences for firefighters, as well as PFAS exposure routes. While firefighters are one of the more widely studied populations affected by PFAS, other frontline workers such as healthcare workers exposed to PFAS compounds are not as widely studied. Some potential sources of PFAS exposure for healthcare workers include personal protective equipment and medical supplies, such as single-use surgical masks, surgical gowns, and X-ray film.
What were the results of this study?
Of the 1,960 Arizona frontline workers analyzed in this study, firefighters had the highest concentrations of PFAS in their blood samples, specifically concentrations of PFHxS, Sm-PFOS, n-PFOS, and PFHpS. The concern over high PFAS concentrations in firefighters leads to consideration of interventions such as limiting contact with PFAS-containing foams and turnout gear, as well as filtration of drinking water.
Serum PFAS levels in other essential workers declined 6%-17% per year over the 3-year study period. However, there were still notable levels of PFAS in their blood samples, which had not been previously reported. This study is among the first to evaluate PFAS levels in individuals working in healthcare and to report moderate elevations of certain PFAS compounds, along with notably higher detection rates of specific compounds like Sb-PFOA and PFDoA, in this group compared to individuals in other professions.
To date, PFAS exposure in healthcare settings has not been widely studied, and the potential sources of exposure remain unclear. It is therefore important to further examine potential sources of exposure for healthcare occupations. Possible exposure routes may include inhalation, ingestion, and skin contact. Preventive measures such as improved water filtration and minimizing contact with PFAS-containing protective gear may help reduce exposure. This study highlights the need to expand evaluation of exposure among other occupations, including healthcare workers.