Study identifies key predictors of ‘forever chemical’ levels in US firefighters

By Dr. Tim Sandle
SCIENCE EDITOR

DIGITAL JOURNAL
February 3, 2026

Firefighters work as an apartment building burns in the Altadena area of Los Angeles county - Copyright AFP JOSH EDELSON

A new study has identified clear occupational factors and demographic indicators associated with elevated serum levels of per- and polyfluoroalkyl substances among U.S. career firefighters.

This state-funded research comes from University of Arizona and Arizona State University, based on data from the Fire Fighter Cancer Cohort Study (established in 2016). The findings provide important insights into the factors that influence PFAS body burdens in this essential workforce.

Understanding the predictors of PFAS accumulation is a critical step toward protecting their long-term health.

PFAS are a class of synthetic chemicals widely used for their water-, grease- and stain-resistant properties. Known as “forever chemicals” due to their persistence in the environment and human body, PFAS have been linked to adverse health outcomes, including immune dysfunction, certain cancers and endocrine disruption.

These chemicals – PFAS – are widespread and represent a large group of over 10,000 synthetic, highly persistent chemicals that have been widely used since the 1940s for their water, grease, and stain-resistant properties. The chemicals are found in everything from raincoats to fire extinguishers.

Firefighters have higher serum PFAS levels than other workers and the general public due to on-the-job circumstances, often in high-risk environments, that expose them to a variety of hazardous substances. This is as measured in human blood plasma levels.

The study shows that fireground practices and departmental protocols significantly influenced PFAS levels, with certain routines related to handling contaminated equipment and personal protective gear associated with higher blood serum concentrations. To gather the data, the researchers worked closely with fire service research champions across six states.

Demographics and lifestyle characteristics, such as years of service, rank or role within the fire service, and personal behaviours, also predicted PFAS levels. These findings highlight that both workplace and personal factors contribute to overall chemical exposure. This evidence suggests that modifications in decontamination procedures, gear storage practices and routine operational policies may reduce exposure to PFAS among firefighters.

Researcher Reagan Conner says: “These study findings underscore the importance of occupational practices in shaping PFAS exposure among firefighters,” Conner said. “By identifying predictors, the fire service can put policies and practices in place to mitigate exposure risks effectively.”

The researchers hope that the study’s insights can help inform targeted interventions, promote safer occupational practices and guide policy recommendations at local, state and federal levels. It is expected that the research findings will help keep firefighters safe within this area of occupational hazard exposure. The findings appear in the Journal of Occupational and Environmental Medicine, titled “Predictors of serum per- and polyfluoroalkyl substances (PFAS) levels among U.S. career firefighters.”