UTHealth Houston study links firefighter smoke exposure to biological changes that increase cancer risk

A new study published in Environmental Research by researchers at UTHealth Houston offers valuable insights into how firefighting can affect the body on a molecular level, potentially leading to long-term health risks such as cancer.

As one of the first studies to connect real-world exposure to fire smoke and measurable biological changes in skin and blood gene activity in firefighters, the research shows promise for occupational health surveillance, enabling early screening and shaping policies that reduce health risks for first responders.

Led by Jooyeon Hwang, PhD, an associate professor of environmental and occupational health at UTHealth Houston School of Public Health, the study examined firefighters’ turnout gear and their microRNA levels. MicroRNAs are small molecules that help regulate gene activity.

The research found that exposure to fires caused measurable changes in their microRNA expression, specifically linked to polycyclic aromatic hydrocarbons, a group of harmful chemicals found in smoke and soot. These biological changes may help explain how repeated firefighting exposure contributes to long-term health risks, including cancer and other serious conditions.

“While the public often sees the immediate and obvious dangers of firefighting, there are growing concerns about what happens inside the body with repeated exposure to fire environments,” said Hwang, who also serves as deputy director of Southwest Center for Occupational and Environmental Health and program director of Industrial Hygiene and Exposure Sciences at the School of Public Health. “Our research is just one example of the kind of work that needs to continue so we can fully understand and reduce long-term health risks for firefighters, especially for the next generation. It also underscores the importance of ongoing education and prevention efforts to limit exposure and better protect those on the front lines.”

Additional researchers for the paper included Jenny R. Gipson; Chao Xu, PhD; Robert Agnew, PhD; and Willard Freeman, PhD, from the University of Oklahoma Health Sciences Center.