Inside the hazard simulation lab at Iowa State University, Guowen Song watches a column of engineered smoke curl upward from a controlled burn. The smoke isn't theatrical — it's data. For Song, a professor and director of the university's NextGen Personal Protective Technology (NexGenPPT) program, it represents a growing threat to the people who run into burning buildings for a living.

"Every day, firefighters across the state are doing heroes' work, but their gear isn't fully protecting them," Song said. "We want to help change that."

That ambition has just become official. Song and his research team helped launch the Iowa Firefighter Cancer Prevention and Exposure Reduction Program, a statewide effort focused on prevention, exposure monitoring, early detection, care navigation and building an Iowa-specific data system to guide future safety standards. The program brings together Iowa State, the University of Iowa's Holden Comprehensive Cancer Center, the Iowa State Fire Marshal Division, the Iowa Fire Service Training Bureau, the Iowa Cancer Consortium and fire departments across Iowa.

For decades, the heavy turnout coats and pants worn by firefighters were seen as near-impenetrable armor. But emerging evidence shows the gear itself has become a second source of exposure. In the lab, Song's team burns synthetic fibers, plastics and lithium-ion batteries under carefully managed conditions to replicate modern structure fires. Their goal isn't just to study smoke — it's to measure the invisible particles and chemicals that can cling to protective gear long after a fire is out.

"Removing, transporting, cleaning and storing contaminated gear are important exposure-control points," Song said. "Research has shown that some contaminants, including polycyclic aromatic hydrocarbons (PAHs) found across turnout-gear layers, can remain after typical cleaning. And this means gear can look clean even when chemicals are still present."

PAHs are not the only worry. Song also pointed to PFAS — per- and polyfluoroalkyl substances — which make products resistant to heat, water, oil and grease but are nearly impossible to destroy. Because of those traits, some firefighting gear textiles and moisture barriers contain PFAS-based materials too. The carbon-fluorine bonds in PFAS do not break down easily, either in the environment or in the human body, and some have been linked to adverse health effects)Skip ahead to why this matters: a landmark National Institute for Occupational Safety and Health (NIOSH) study of nearly 30,000 career firefighters in three major U.S. cities found firefighters had a 9% higher cancer-diagnosis rate and a 14% higher cancer-mortality rate than expected based on U.S. population rates. That is the real cost of the job.

Song leads an interdisciplinary team of researchers, postdoctoral fellows and graduate students who are working to turn this science into practical answers — safer materials, better cleaning methods)Skip ahead — including how to separate PFAS already present in gear from contaminants deposited by smoke, so future gear can be designed and cleaned more safely. "There is a real opportunity to improve firefighter safety through this work," he said.