Firefighters risk their lives daily to protect others, but new research shows they may be facing a silent, long-term threat from within their own protective gear.
A study by the University of Arizona has uncovered how exposure to industrial chemicals known as PFAS (per- and polyfluoroalkyl substances) is linked to changes in gene-regulating molecules, potentially increasing firefighters’ risk of cancer, neurological disorders, and autoimmune diseases.
This emerging evidence sheds light on the hidden biological consequences of PFAS exposure, signalling a pressing need to rethink occupational safety in the fire service.
PFAS and their ubiquity in firefighting
PFAS are synthetic chemicals used in a wide range of products due to their heat, oil, and water-resistant properties.
Found in non-stick cookware, electronics, textiles, and most concerningly, in firefighting foam and protective gear, these substances are notoriously persistent in the environment and the human body, earning the nickname ‘forever chemicals.’
Firefighters face elevated PFAS levels through routine occupational contact with these materials. Unlike the general population, they encounter these compounds through both their gear and the chemical-laden smoke from burning materials.
From chemical exposure to genetic changes
In this study, researchers analysed blood samples from over 300 firefighters stationed across six different US regions.
They measured the levels of nine types of PFAS and examined their influence on miRNAs – tiny molecules responsible for regulating gene expression. These miRNAs don’t alter genes directly but act like switches, turning genetic activity on or off.
The analysis revealed a compelling link: higher blood concentrations of PFAS were associated with specific changes in miRNA activity.
These changes affected biological pathways linked to multiple cancers, neurological disorders such as Alzheimer’s, and autoimmune conditions like lupus and asthma.
One PFAS compound, perfluorooctane sulfonic acid (PFOS), was particularly influential. It was connected to decreased levels of miR-128-1-5p, a microRNA implicated in cancer suppression.
Variants of PFOS were also found to affect several other miRNAs tied to cancer development and progression.
A wide-reaching health concern
The study highlighted potential molecular precursors to a wide array of diseases. PFAS-related miRNA alterations were associated with biological pathways for leukaemia, bladder, liver, breast, and thyroid cancers.
These changes were also linked to conditions like Alzheimer’s and infectious diseases, including tuberculosis.
Although the study stopped short of establishing direct causation between PFAS and specific diseases, it strongly suggests that PFAS exposure plays a role in setting the stage for disease through epigenetic changes.
These alterations, while not modifying the DNA sequence itself, can have lasting impacts on gene behaviour.
Towards early detection and prevention
One of the most promising aspects of this research lies in its implications for early disease detection.
By identifying miRNA signatures that arise from PFAS exposure, scientists may be able to develop biomarkers that signal elevated disease risk – long before symptoms appear.
This could open new doors for preventive care and targeted interventions, especially in high-exposure occupations like firefighting.
Moreover, as pharmaceutical companies begin exploring therapies that can reverse or modify epigenetic changes, understanding the link between PFAS and miRNA disruptions could play a pivotal role in shaping future treatment strategies.
The findings are part of ongoing efforts under the Fire Fighter Cancer Cohort Study. With continued monitoring and deeper molecular research, the goal is to pinpoint not only the risks associated with PFAS exposure but also actionable steps to mitigate them, ranging from policy changes in firefighting gear design to new medical screening protocols.
A wake-up call for occupational safety
This landmark study underscores the urgent need for increased awareness of the health implications tied to PFAS exposure in firefighting.
By connecting chemical exposure to early genetic changes, the research lays critical groundwork for future protections and health monitoring systems for first responders.