Firefighting is a profession with an elevated occupational risk for cancer due to chronic exposure to a complex mixture of toxic byproducts resulting from combustion. This unique exposure profile has established a link between firefighting and a higher incidence of various cancers. Understanding the specific causes of this increased risk and implementing targeted preventative measures are paramount for protecting the health of those who serve.
Statistical Evidence of Increased Risk
Scientific investigations have established a clear connection between the profession and increased cancer risk. A landmark study by the National Institute for Occupational Safety and Health (NIOSH) analyzed the health data of nearly 30,000 career firefighters. This research found that the study population had a nine percent higher risk of being diagnosed with cancer and a 14 percent higher risk of dying from a cancer-related illness compared to the general U.S. population.
The elevated risk is not uniform across all cancer types, but specific diseases show a statistically significant increase. Firefighters have shown a two-fold excess risk for malignant mesothelioma, a cancer strongly associated with asbestos exposure. Studies using the standardized incidence ratio (SIR) confirm higher rates for prostate, bladder, and testicular cancers. The evidence linking this occupation to cancer is substantial, leading the International Agency for Research on Cancer (IARC) to classify occupational exposure as a firefighter as a Group 1 carcinogen.
Primary Carcinogenic Exposures
The primary source of carcinogenic exposure is the dense, toxic smoke produced during a structure fire. Modern buildings contain vast amounts of synthetic materials, such as plastics and engineered wood, that release a complex chemical cocktail when burned. This process generates significantly more toxic smoke than fires of previous decades, creating a hazardous environment long after the flames are extinguished.
Fire smoke contains numerous known human carcinogens, including polycyclic aromatic hydrocarbons (PAHs), benzene, formaldehyde, and asbestos. PAHs are concerning components of soot and incomplete combustion, with some classified as Group 1 carcinogens by the IARC. Firefighters are also exposed to per- and polyfluoroalkyl substances (PFAS) from aqueous film-forming foam (AFFF) and the coatings on their turnout gear.
These toxic substances enter the body through three main pathways: inhalation, ingestion, and dermal absorption. While respiratory protection prevents inhalation, carcinogens can be ingested through hand-to-mouth contact, such as eating without washing hands after a fire. Dermal absorption is a major route of systemic exposure, particularly in the high-heat environment of a fire. Heat causes pores to open and sweating increases skin permeability, allowing soot and gaseous carcinogens to penetrate easily, especially in areas like the neck, jaw, and hands.
Exposure continues beyond the fireground, as contaminants cling to personal protective equipment (PPE) and are carried back to the fire station. Soiled items can off-gas toxins into the apparatus cab and living quarters, contaminating surfaces and integrating into the station’s dust. Furthermore, daily exposure to diesel exhaust from fire apparatus, classified as a Group 1 human carcinogen, contributes to the chronic risk profile.
Cancers Most Frequently Linked to Firefighting
Cancers showing the most consistent elevation often correspond to the primary routes of exposure and the types of toxins encountered. The NIOSH study noted a significantly increased incidence of several digestive system cancers, including colon and rectal cancer. These cancers are often linked to the ingestion and systemic absorption of combustion byproducts.
Cancers of the genitourinary tract, such as prostate, bladder, and testicular cancer, are consistently found at higher rates. The elevated risk for bladder cancer is related to the body’s processing and excretion of absorbed chemical carcinogens. Skin cancer, including malignant melanoma, is a specific concern, often linked to the deposition and dermal absorption of PAHs and other surface contaminants.
Hematological cancers, which affect the blood and lymph system, also show increased mortality rates, including non-Hodgkin lymphoma and multiple myeloma. Respiratory cancers, such as lung cancer and mesothelioma, are associated with the inhalation of known lung irritants and carcinogens like asbestos and combustion products.
Strategies for Risk Reduction
To combat these risks, modern firefighting protocols focus intensely on reducing exposure through decontamination and protective practices. The mandatory use of the Self-Contained Breathing Apparatus (SCBA) throughout the entire incident, including the overhaul phase, is a primary strategy. This ensures respiratory protection is maintained even after visible smoke dissipates, as toxic gases and airborne carcinogens persist. Relying on carbon monoxide (CO) or hydrogen cyanide (HCN) readings to determine air safety is discouraged, since these gases do not correlate with the presence of cancer-causing toxins.
Immediate on-scene gross decontamination of gear and personnel is necessary to prevent the spread of contaminants. This involves using a hose and brush to wash loose soot and particles from the exterior of the turnout gear while the firefighter remains on SCBA. Following gross decon, exposed skin areas, especially the face, neck, and hands, must be wiped down using specialized cleansing wipes or soap and water before leaving the scene.
Contaminated PPE must be immediately bagged and sealed in heavy-duty plastic bags to prevent off-gassing into the apparatus cab or station environment. The “shower within the hour” mandate requires firefighters to shower thoroughly and change into clean clothes upon returning to the station. Regular medical monitoring and cancer screening are also adjusted for this high-risk population. Guidelines recommend that firefighters begin screenings for cancers like colon, prostate, and skin at an earlier age and with greater frequency than the general public.