By Leila Merrill
TUCSON, Ariz. — A new study has identified a potential basis for increased risks of diseases such as cancer in firefighters.
Researchers with the University of Arizona Mel and Enid Zukerman College of Public Health found changes in the cellular mechanisms that control gene expression, called epigenetics. After multiple fire exposures, the researchers found changes in DNA methylation.
“This is significant new data for firefighters,” said public health professor Jeff Burgess, MD, MS, MPH. Burgess led the research team. “We have known there is a higher incidence of cancers among firefighters, and this research potentially shows us the mechanism through which the exposures that firefighters face on the job lead to increased health risks.”
Epigenetic changes can function as biomarkers, showing changes that may contribute to disease risk or development.
For this study, the team took blood samples from 50 firefighter recruits with the Tucson Fire Department who do not smoke cigarettes. This was done before their first live fire training and again after 20-37 months of working. The participants were 98% male and 94% white.
In the latter blood samples, the research team found DNA methylation alterations at 680 different sites on the genome. Many of those were in genes linked to cancers, immune and nerve system function and other illnesses such as cardiovascular disease.
“We do not know yet whether these alterations will lead to cancer,” said Jaclyn Goodrich, Ph.D., research assistant professor of environmental health sciences at the University of Michigan School of Public Health and first author on the paper. “Even so, this study is an important step in understanding the biological pathways that could underlie these risks.”
The DNA methylation alterations could be used to inform risk assessments for firefighters and could be used for prevention efforts.
The paper, “Repeat measures of DNA methylation in an inception cohort of firefighters,” was published in the journal Occupational & Environmental Medicine and is available online.