Firefighters may face an elevated risk of developing prostate cancer due to exposure to chemicals on the job, according to a new study from the University of Arizona’s Mel and Enid Zuckerman College of Public Health and the University of Michigan, conducted in collaboration with fire service partners and researchers across the United States through the Firefighter Cancer Cohort Study.
Prostate cancer is the most common type of cancer among men in the United States, while in Spain, according to the Spanish Society of Medical Oncology (SEOM), it will be the most frequently diagnosed tumor in men in 2024, with 30,316 new cases. In the United States, firefighters have a prostate cancer diagnosis rate 1.21 times higher than that of the general population, which could be related to exposure to chemicals, including smoke and foam used in firefighting.
These chemicals could influence gene expression through a process known as epigenetic modification. Some of these modifications, such as DNA methylation, are factors that contribute to the development of cancer. The researchers found that more experienced firefighters showed different epigenetic modifications than novice firefighters in genetic areas linked to prostate cancer.
“With these published findings, we have concrete evidence of the health risks firefighters face due to cumulative exposure at work,” said Dr. Jeff Burgess, director of the Firefighters and Health Collaborative Research Center. professor at the Zuckerman College of Public Health. The study has been published in the journal Environmental and Molecular Mutagenesis.
PFAS exposure linked to increased cancer risk
Burgess, also a member of the BIO5 Institute, has researched firefighter health for decades. She worked collaboratively with lead author Margaret Quaid and University of Michigan researcher Jackie Goodrich, who led the gene methylation analysis. They found that experienced firefighters had epigenetic modifications on chromosome 8q24, an area of the genome where these modifications have been linked to prostate cancer risk, compared to newer firefighters.
One class of chemicals linked to epigenetic modifications are perfluoroalkyl and polyfluoroalkyl substances, or PFAS, used in firefighting foams as well as various household items, including nonstick pans and waterproof clothing. The research team also examined whether there is a relationship between PFAS exposure and epigenetic modification.
“With these published findings, we have concrete evidence of the health risks that firefighters face due to cumulative exposure at work.”
The results indicated that both novice and experienced firefighters at many fire departments had similar exposures to PFAS. However, exposure to a specific PFAS, branched-chain perfluorooctanoic acid, or PFOA, was linked to epigenetic modifications.
“This study demonstrates the ability of the Firefighter Cancer Cohort Study to combine data from different grants – in this case, awarded by the Federal Emergency Management Agency in 2014, 2015 and 2018 – to more effectively evaluate questions about the fire service, this time about exposures and increased risk of prostate cancer,” Burgess explained.
Increased risk of urological tumors in firefighters
Another recent study by researchers at the UTHealth Houston School of Public Health has also revealed that biomarkers in the urine of firefighters after fighting fires indicate an elevated risk of developing urological cancers. The researchers, led by Jooyeon Hwang, associate professor in the Department of Environmental and Occupational Health Sciences at the UTHealth Houston School of Public Health, identified key biological molecules linked to kidney, bladder and prostate cancer in the urinary protein profiles of Oklahoma firefighters after being exposed to smoke in emergency fires.
This study, carried out in collaboration with the National Institute for Occupational Safety and Health and whose results have been published in the journal Science of The Total Environment, is the first to record the use of urine analysis to evaluate the effects of exposure to fire smoke in fire brigade. “This initiative aims to significantly improve early detection and continuous health monitoring, optimizing the overall health management of firefighters,” Hwang explained.
Hwang and his team collected urine samples from 10 firefighters before and after their exposure to wildfire smoke and compared the protein markers in the samples to urine panels from previous studies. This analysis revealed that of the 16 proteins identified in urine after firefighters were exposed to smoke, seven were related to known cancer biomarkers.
This study highlights the occupational health risks for firefighters and the need for comprehensive health assessments and cancer screening. According to the article’s recommendations, “integration of cancer screening into current physical and medical examinations for new recruits and active firefighters” should be initiated to detect early cases of cancer.
