Firefighters develop cancer at significantly higher rates than the general population because they are repeatedly exposed to a complex mix of carcinogens through their skin, lungs, and even their own protective gear. In 2022, the International Agency for Research on Cancer reclassified occupational exposure as a firefighter to Group 1, its highest category, meaning the evidence is sufficient to say the job causes cancer in humans. The specific cancers linked to the profession range across nearly every organ system, from the bladder and colon to the brain and blood.
Which Cancers Hit Firefighters Hardest
Not every type of cancer is equally elevated in firefighters. A large meta-analysis pooling data from studies worldwide found the sharpest increase in testicular cancer, with firefighters facing a 68% higher risk than the general population. Prostate cancer risk was 26% higher, and non-Hodgkin’s lymphoma risk was 37% higher. Melanoma risk was elevated by 34%, bladder cancer by 18%, and colorectal cancer by 13%. Brain and central nervous system cancers were 26% more common.
Blood cancers also show up disproportionately. Hodgkin’s lymphoma risk was 51% higher when incidence and mortality data were combined, and multiple myeloma showed a 28% increase in mortality. Kidney cancer mortality was 29% higher. Interestingly, lung cancer rates are not significantly elevated in firefighters, likely because the profession selects for people with strong cardiovascular fitness, many of whom don’t smoke. The cancers that are elevated tend to be the ones driven by chemical exposure through the skin and bloodstream rather than direct inhalation alone.
What Burns Today Is Far More Toxic
Modern homes are filled with synthetic materials: polyurethane foam in furniture, engineered wood products bonded with resins, plastic electronics, and vinyl flooring. When these materials burn, they produce a more toxic chemical cocktail than traditional wood fires. Burning plastic generates the most potent effects on lung function and inflammation of any commonly studied fuel type, and flaming conditions make the output worse.
Among the hundreds of chemicals in structural fire smoke, polycyclic aromatic hydrocarbons (PAHs) are the best understood cancer drivers. One compound in this group, benzo[a]pyrene, is classified as a definite human carcinogen and is specifically linked to cancers of the skin, lung, and bladder. PAHs have also been directly shown to cause DNA damage in human blood cells during fire suppression exercises. The strongest evidence ties PAH exposure to cancers of the colon, skin, lung, bladder, and kidney, which maps closely onto the cancers most elevated in firefighter populations.
Skin Absorption Is the Overlooked Route
Most people assume firefighters get cancer from breathing in smoke, and inhalation is part of the picture. But dermal absorption, where chemicals pass directly through the skin into the bloodstream, may be just as important. During active firefighting, body temperature rises, pores open, and skin becomes damp with sweat. All of these conditions increase the rate at which toxic chemicals cross the skin barrier. The neck, jaw, wrists, and groin are particularly vulnerable because protective gear fits loosely or leaves gaps in those areas.
One study measuring PAH levels on firefighters’ skin found that contamination jumped by 232% after a fire call compared to the start of a shift. Showering afterward reduced skin PAH levels by about 64%, which is meaningful but far from complete. And an enhanced shower protocol using special cleansing products performed no better than a standard shower, suggesting that once these chemicals bind to skin, they’re difficult to remove entirely.
The Gear Itself Contains Carcinogens
In a troubling twist, the turnout gear designed to protect firefighters contains per- and polyfluoroalkyl substances (PFAS), the so-called “forever chemicals” linked to kidney cancer, testicular cancer, and other health problems. Research from the National Institute of Standards and Technology found PFAS in every layer of turnout gear, with the outer shell and moisture barrier containing concentrations up to 400 times higher than the thermal liner closest to the skin.
Outer shell fabrics that had been treated with water-repellent coatings consistently contained the greatest amounts of PFAS, while untreated fabrics contained far less. The concern is that heat, UV exposure, laundering, and normal wear and tear may cause PFAS to migrate from gear and into contact with firefighters over time. Whether that happens primarily through skin contact, inhalation of degraded fibers, or ingestion from hand-to-mouth transfer is still being investigated, but the chemicals are present in significant quantities in equipment firefighters wear for years.
Fire Stations Are Not Clean Air Zones
Exposure doesn’t stop when the fire is out. Diesel exhaust from fire trucks idling inside stations spreads particulate matter throughout the building. Diesel exhaust particulates are classified as reasonably anticipated to cause cancer in humans. Measurements in fire stations across New York, Boston, and Los Angeles found airborne particulate levels ranging from under 100 to 480 micrograms per cubic meter during normal station time, with worst-case readings reaching 748 micrograms per cubic meter. Firefighters sleep, eat, and exercise in these environments between calls.
Contaminated gear adds to the problem. PAHs have been detected on equipment that had already been cleaned and was staged as ready to use, meaning exposure can resume the moment a firefighter handles their gear for the next call. Soot and residue on helmets, hoods, and gloves create a low-level but persistent source of skin contact with carcinogens throughout a career.
Cancer Can Take Years to Appear
One reason the link between firefighting and cancer was slow to be recognized is that these cancers don’t develop quickly. Solid tumors like colon, bladder, and prostate cancers have minimum latency periods of at least four years from exposure, and lung cancers linked to soot and combustion products take a minimum of nine years to appear. Mesothelioma, linked to asbestos still present in older buildings, has a minimum latency of 11 years. Blood cancers like leukemia and lymphoma can develop faster, with minimum latencies as short as a few months, but they often take much longer.
This delay means a firefighter may be diagnosed five, ten, or twenty years after the exposures that triggered the cancer. It also means that career firefighters accumulate damage over decades before symptoms ever appear, and the total burden of exposure matters more than any single fire. A firefighter who responds to hundreds of structural fires over a 25-year career has a fundamentally different risk profile than someone exposed to a single event.
Why Decontamination Only Goes So Far
Fire departments have made real progress in adopting on-scene decontamination practices: wiping down skin immediately after a fire, bagging contaminated gear, and showering as soon as possible. These steps help. A standard shower cuts skin PAH levels by roughly two-thirds. But the remaining third still enters the body, and many exposures happen during the fire itself, before any decontamination is possible.
The cumulative nature of the problem is the core challenge. Each fire deposits a new layer of carcinogens on skin, in lungs, and on gear. Decontamination reduces the dose but cannot eliminate it. PFAS in turnout gear provides a baseline chemical exposure that exists independently of any fire. Diesel exhaust in stations adds another layer. And the synthetic materials filling modern homes ensure that each structural fire produces a denser, more varied toxic payload than fires of previous generations. The cancer risk firefighters carry is not from a single failure of protection. It is built into the nature of the work itself.