Quick look
Iowa State researchers are leading a new statewide initiative that aims to lower firefighters’ cancer risk, with a focus on prevention efforts and developing practical solutions that Iowa fire departments can use to reduce their exposure.
AMES, Iowa – 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. And for Song, professor and the Noma Scott Lloyd Endowed Chair of apparel, events and hospitality at Iowa State, it represents a growing occupational‑health threat facing Iowa firefighters.
“Every day, firefighters across the state are doing heroes’ work, but their gear isn’t fully protecting them,” said Song, who directs the university’s NextGen Personal Protective Technology (NexGenPPT) program. “We want to help change that.”
Song and his Iowa State research team recently helped launch the Iowa Firefighter Cancer Prevention and Exposure Reduction Program, a new statewide initiative focused on prevention, exposure monitoring, early detection, care navigation and building an Iowa-specific data system to guide future safety standards.
Iowa State is leading the program in collaboration with partners at the University of Iowa’s Holden Comprehensive Cancer Center, the Iowa State Fire Marshal Division and the Iowa Fire Service Training Bureau, the Iowa Cancer Consortium, and fire departments throughout Iowa.
“Our research is part of a broader effort to understand a changing fire environment and to help turn that science into practical solutions for reducing exposure,” said Song, who leads an interdisciplinary team of research faculty, postdoctoral fellows and graduate students at Iowa State.
“There is a real opportunity to improve firefighter safety through this work.”
A hidden hazard in the gear
For decades, the heavy turnout coats and pants worn by firefighters have been seen as near-impenetrable armor, but Song said emerging evidence shows personal protective equipment (PPE) has become a secondary source of exposure.
In the lab, Song and his team burn synthetic fibers, plastics and lithium‑ion batteries under precisely managed conditions to replicate modern structure fires. Their goal isn’t just to study smoke, but to understand and measure the invisible particles and chemicals that can remain on a firefighter’s protective gear long after a fire is extinguished.
“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.”
Song also cited PFAS – or per- and polyfluoralkyl substances – as a related but distinct concern. PFAS are used in many consumer products because they make items resistant to heat, water, oil and grease. They are also nearly impossible to destroy. And given those traits, some firefighting turnout-gear textiles and moisture barriers contain PFAS-based materials, too.
“PFAS have strong carbon-fluorine bonds that do not break down easily in the environment or the human body, and some PFAS have been associated with adverse health effects,” Song said. “However, researchers are still determining how much firefighter exposure comes from gear compared with other sources, and this makes separating PFAS already present in materials from contaminants deposited by smoke important for designing safer gear and better cleaning methods.”
Song said 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 faced a 9% higher cancer-diagnosis rate and a 14% higher cancer-mortality rate when compared to the number of cancers expected using U.S. population rates.
“Occupational cancer is now the leading cause of firefighter death, and while the NIOSH study doesn’t represent the full range of the fire service, it does clearly show why exposure prevention and broader data collection are needed,” Song said.
But why is firefighter PPE less effective today?
The answer comes down to the nature of fire itself, said Rui Li, a research assistant professor in apparel, events and hospitality who has been working with the NextGenPPT program at Iowa State since 2021.
“Traditional PPE was designed primarily to protect against extreme heat and basic toxic gases,” Li said. “But today’s structure and vehicle fires involve plastics, synthetic textiles, electronics and lithium-ion batteries, and when these materials burn, they can produce complex mixtures of volatile chemicals, PAHs, ultrafine soot and metal-containing particles. These kinds of hazards weren’t considered in past design and certification.”
A lab for modern fires, changing exposures
To study and better understand these shifting hazards, Iowa State built one of the nation’s only labs capable of generating controlled, realistic fire emissions and analyzing their chemistry, particle behavior and toxicity.
Li said Iowa State’s ACCESS research platform allows the team to reproduce select controlled oxygen and ventilation levels, making it possible to generate emissions from wood, mixed synthetic materials and battery-involved fires; measure particle size and chemistry; expose fabric and gear components to defined smoke; test filtration and decontamination methods; and study biological effects using laboratory models.
“We can create different types of emissions, characterize them and use them for PPE testing,” Li said. “It’s more realistic than anything used in certification today.”
Li said lithium‑ion batteries and energy‑storage systems have made smoke more complex, producing heavy metals and fine soot particles that lodge deep in gear layers. And those particles don’t stay put.
“They can resuspend into the environment and potentially migrate from fire scenes to stations, vehicles, shared workspaces and homes,” Li said.
Exposure spikes during “donning and doffing,” a term researchers use to describe the process of putting on and removing gear. But even exercising near contaminated gear – such as in a station’s truck bay – can pull invisible carcinogens into the lungs, Song said.
An Iowa challenge with rural stakes
While urban fire departments face these hazards, Song and Li said the challenge is different in rural America, where fire departments rely much more heavily on volunteers. Approximately 90% of Iowa firefighters are volunteers, a rate that’s significantly higher than the national average.
“Larger fire departments are more likely to have dedicated quarters, commercial-grade cleaning extractors and multiple sets of gear,” Song said. “Volunteer firefighters may wear their PPE at a fire, put it in the trunk and bring it home – along with the carcinogens.”
Song said the issue is compounded by the fact that current cleaning methods don’t fully remove deep-seated toxins: “PPE can look perfectly clean, but the toxic material is still there, and it accumulates over time,” Song said. “So, the question really becomes, ‘How clean is clean?'”
“We’re committed to working closely with Iowa fire departments to identify practices that are both effective and realistic for communities with limited staff, equipment and budgets,” Song said. “This includes keeping contaminated gear out of passenger compartments and homes, improving on-scene decontamination, and finding practical ways to document exposure and cleaning.”
Over the past several years, the Federal Emergency Management Agency (FEMA) has awarded significant funding to help support Song’s firefighter-protection research and related collaborative projects, and Song said this investment has helped build the scientific foundation, facilities and partnerships behind the Iowa Firefighter Cancer Prevention and Exposure Reduction Program.
“The goal now is to translate that foundation into practical applications, including exposure-monitoring tools, decontamination guidance, and training and prevention strategies that fire departments can use,” he said.
Preparing for the future
Song said he also hopes the new Iowa Firefighter Cancer Prevention and Exposure Reduction Program will serve as a valuable education resource.
“At Iowa State, undergraduate and graduate students can follow the full chain from controlled combustion and particle measurement to contaminated textiles, health questions and prevention strategies,” he said. “The work connects materials science, chemistry, engineering, toxicology, public health, data science and communication around a problem that directly affects Iowa communities.”
Song and his team envision creating classroom-ready experiments, virtual laboratory demonstrations and outreach activities for middle and high school students.
“We want to help young people understand why modern fires have changed, and how science, design and public services can work together to make communities safer,” Song said.
Song said lasting progress will require sustained collaboration among researchers, health professionals, fire-service leaders, manufacturers and policymakers, along with a willingness to rethink long-standing assumptions about gear and exposure.
“We’ve heard from firefighters that a fire scene isn’t just a fire scene anymore,” Song said. “Fires have become hazmat scenes and that demands a change in their approach. If we can help shorten the turnaround time between identifying new hazards and upgrading gear, that makes a real difference in the field.”
Song said he also finds deep motivation in the firefighters who have shared their stories – and their gear – with his team.
“Firefighters shouldn’t have to choose between serving their communities and protecting their health,” he said. “Our job is to make sure they don’t.”
