The Oak Park Fire Department has enrolled in a long-term University of Illinois research project examining how firefighting affects cancer risk, joining a statewide cohort that now includes more than 100 Illinois departments.
Participating firefighters give blood and urine samples, complete a baseline health questionnaire and an annual cancer survey, and log their exposures after incidents so researchers can connect specific occupational exposures to later health outcomes. Participation is voluntary and can be withdrawn at any time. The study is designed to follow participants for up to 30 years.
For the roughly 79 sworn firefighters, paramedics and civilian personnel the department employs, and for firefighters across the region, the enrollment is less a news event than a data event. It adds another department to one of the few research efforts positioned to answer questions that decades of smaller studies have left open.
The Established Evidence and the Remaining Questions
The link between firefighting and cancer is no longer in scientific dispute at the hazard level. In 2022, a working group of 25 experts from eight countries convened by the World Health Organization's International Agency for Research on Cancer classified occupational exposure as a firefighter as carcinogenic to humans, its highest hazard category, upgrading an earlier evaluation that had placed the exposure in the possibly carcinogenic group.
That review found sufficient evidence in humans for mesothelioma and bladder cancer, and limited evidence for colon, prostate and testicular cancer, melanoma of the skin and non-Hodgkin lymphoma. A large federal study of nearly 30,000 career firefighters from San Francisco, Chicago and Philadelphia had earlier found elevated rates of several cancers compared with the general population, including a roughly twofold increase in mesothelioma.
What remains unsettled is the part that matters for prevention. Which specific exposures on which kinds of fires drive which cancers? How much do gear decontamination, fire station air quality, shift work, and diesel exhaust each contribute? Do biological changes appear early enough to be detected and acted on? Firefighters have historically been studied as a group defined by job title rather than by measured exposure, and women and volunteer firefighters have been underrepresented.
Biomarkers, a Mobile Laboratory and a Three-Decade Horizon
The Illinois Firefighter Cancer Risk Study is built to close that gap by measuring exposure directly rather than inferring it. The project focuses on how accumulated occupational toxicants, including per- and polyfluoroalkyl substances, polycyclic aromatic hydrocarbons and heavy metals, relate to later cancer risk.
Farzaneh Masoud, director of research at the Illinois Fire Service Institute, described the design as tracking both exposure and biological effect. Researchers examine biomarkers of exposure alongside biomarkers of effect, she said, using annual sample collection to study genotoxicity and how accumulated toxicants and carcinogens act on the body over time. She said the goal is early detection, and described the fire service as a severely understudied population.
Logistics have historically been a barrier to this kind of research, since firefighters work rotating shifts across dispersed stations. The institute operates a 40-foot mobile laboratory that travels to stations to collect samples, removing the need for participants to arrange separate appointments.
Enrollment is open to firefighters aged 18 and older, including retirees, emergency medical responders, volunteers and career personnel of any rank. The study began in late 2024.
The Payoff for Departments Is Screening, Not Just Data
Oak Park Fire Chief JT Terry framed participation as serving current members as well as future ones, saying the department hopes to benefit its own firefighters through enhanced screening and early detection while contributing to research improving safety across Illinois and beyond. He noted that the study brings together scientific expertise and "resources that individual fire departments simply cannot replicate" on their own.
That is the practical trade for a municipal department. Individual fire agencies cannot fund longitudinal biomonitoring, but they can enroll in one, and participants receive health screening they would not otherwise get on a department budget.
The households most directly affected are firefighter families, who carry a documented occupational cancer burden and often navigate presumptive-coverage rules that vary by state. Illinois and most states have laws creating a presumption that certain cancers in firefighters are job-related for workers' compensation purposes, though the covered cancer list and the service requirements differ. Research of this kind can eventually inform which conditions those laws cover.
Firefighters outside Illinois can enroll in the CDC's National Firefighter Registry for Cancer, which the agency reported has surpassed 40,000 members, making it the largest firefighter cohort in the country. The registry is open to career and volunteer firefighters, active or retired, with or without a cancer diagnosis.
Nothing Has Been Concluded Yet
It is worth stating plainly what this study has not done. It has produced no results. It is an enrollment milestone in an observational cohort designed to generate findings over decades, not a report of new evidence about cancer risk.
Cohort studies of this design can identify associations between measured exposures and later disease. They cannot, on their own, prove that a specific exposure caused a specific cancer in a specific person. Early biomarker findings, when they come, will describe biological changes whose clinical meaning may take years to interpret.
Nothing about current medical guidance changes because of this enrollment. Firefighters should continue following their department's decontamination protocols, wearing self-contained breathing apparatus through overhaul, and keeping up with age-appropriate cancer screening and any occupational screening their department or union offers.
The next developments to watch are the study's first published biomarker analyses, additional department enrollments across Illinois, and continued growth of the federal registry. The confirmed fact is that another Chicago-area department has joined a long-term cancer cohort. The people most affected are firefighters and their families. The reasonable action for firefighters is enrolling in the Illinois study or the national registry. The central uncertainty is which exposures drive which cancers, which is exactly what the research is built to answer.
Key Questions Answered
What exactly did the Oak Park Fire Department do? It joined the Illinois Firefighter Cancer Risk Study run through the University of Illinois, in which participating firefighters provide blood and urine samples, complete health questionnaires and log fire exposures over a study period lasting up to 30 years.
Has this study found anything about cancer risk yet? No. This is an enrollment announcement, not a results announcement. The cohort began in late 2024 and is designed to generate findings over decades.
Is the link between firefighting and cancer already established? The World Health Organization's cancer agency classified occupational exposure as a firefighter as carcinogenic to humans in 2022, citing sufficient human evidence for mesothelioma and bladder cancer. What remains unclear is which specific exposures drive which cancers.
Who can participate? Firefighters aged 18 and older, including retirees, emergency medical responders, volunteers and career personnel of any rank across participating Illinois departments.
What do firefighters get out of joining? Participants receive periodic health screening and biomarker testing that individual departments generally cannot fund, along with contributing data toward prevention research.
Is there an option for firefighters outside Illinois? Yes. The CDC's National Firefighter Registry for Cancer is open nationally to career and volunteer firefighters, active or retired, whether or not they have a cancer diagnosis.
Does this change any current safety guidance? No. Existing recommendations on gear decontamination, respiratory protection through overhaul, and routine cancer screening remain the standard.
