Firefighter Health Risks: Cardiac Events, Cancer & Occupational Hazards

Firefighting is one of the most physically demanding occupations in the United States, and also one of the most hazardous. Beyond the immediate dangers of fire and structural collapse, firefighters face long term risks from things like cardiac events and occupational cancer exposure. This page consolidates current data on the leading health threats facing career and volunteer firefighters.

Sources: NFPA Firefighter Fatalities in the United States (2024); CDC/NIOSH Fire Fighter Fatality Investigation and Prevention Program; peer-reviewed research published in PMC/NIH; IARC Monographs on the Identification of Carcinogenic Hazards to Humans (2022); USFA firefighter fatality data.

Leading Causes of Firefighter Line-of-Duty Death

Firefighter line of duty deaths (LODDs) fall into two broad categories: traumatic deaths (burns, structural collapse, vehicle accidents) and sudden cardiac events. Cardiac events consistently account for the largest single share of annual LODDs.

In 2024, NFPA recorded 62 on-duty firefighter fatalities. Of those:

• 30 (48%) were cardiac-related & 20 occurred on duty and 10 within 24 hours of duty (NFPA, 2024)
• Firefighters aged 40–49 accounted for the highest number of deaths (20 of 62)

Over the long term, sudden cardiac events have accounted for approximately 45–50% of all duty-related firefighter fatalities across the past four decades (NFPA).

Cardiac Risk During Fire Suppression

The cardiac risk to firefighters is not evenly distributed across their duties. Fire suppression activities (i.e. the act of entering and fighting a structure fire) represent a small fraction of total working time but carry a disproportionate share of the cardiac risk.

Key findings from peer reviewed research (Kales et al., published in PMC/NIH):

• Fire suppression comprises only 1–5% of annual firefighter working time, yet accounts for more than 30% of line-of-duty coronary heart disease (CHD) deaths
• The relative risk of sudden cardiac death during fire suppression compared to nonemergency duties: RR 22.1 (95% CI: 14.8–32.9) in firefighters aged 45 and under
• Firefighters work at near-maximal heart rates while wearing approximately 50 pounds of protective equipment in high-heat environments
• Heat stress and dehydration reduce cardiac output despite sustained elevated heart rate, increasing the risk of arrhythmia and cardiac arrest
• 98% of cardiac fatalities in firefighters are attributed to stress and overexertion (NIOSH)

Individual Risk Factors

Research has identified several pre-existing conditions that substantially amplify cardiac risk during fire suppression (NIOSH/CDC):

Source: NIOSH Fire Fighter Fatality Investigation and Prevention Program; CDC NIOSH Bulletin “Preventing Fire Fighter Fatalities from Cardiovascular Events.”

Cancer Risk in Firefighters

Cancer has emerged as the leading cumulative cause of firefighter death, surpassing traumatic causes when measured across career length! In 2022, the International Agency for Research on Cancer (IARC) classified occupational exposure as a firefighter as Group 1: carcinogenic to humans: that’s the highest classification, reserved for agents with sufficient evidence of carcinogenicity in humans.

Key statistics from a 2023 meta-analysis of 38 studies (PMC/NIH) and the American Cancer Society:

• Firefighters have a 9% higher risk of cancer diagnosis compared to the general population
• Firefighters have a 14% higher risk of cancer mortality compared to the general population
• Cancer accounted for 66% of career firefighter line-of-duty deaths between 2002 and 2019

Cancers with Elevated Risk in Firefighters

Source: Cancer risk and mortality among firefighters, meta analytic review, PMC/NIH (2023); IARC Monographs Vol. 132 (2022); American Cancer Society.

Carcinogenic Exposures on the Fireground

Firefighters are exposed to a complex mixture of carcinogens during and after fire suppression. Research measuring airborne concentrations at fire attack positions has found:

• Polycyclic Aromatic Hydrocarbons (PAH): 17,800–23,800 µg/m³ at attack positions vs. fewer than 30 µg/m³ at command positions
• Hydrogen cyanide (HCN): 33.5 ppm at attack positions, exceeding NIOSH recommended exposure limits
• Additional exposures include benzene, formaldehyde, diesel exhaust, asbestos, and PFAS chemicals in older protective gear

Source: Management of Firefighters’ Chemical and Cardiovascular Exposure Risks on the Fireground, PMC/NIH (2022).

Occupational Health Protections

The fire service has made significant progress on occupational health protections in the past decade:

• Cancer presumption laws: Most U.S. states now have cancer presumption statutes that establish certain cancers as work-related for firefighters without requiring the firefighter to prove occupational causation. The number of states with these laws has grown significantly since 2010.
• Post-fire decontamination: NFPA 1851 and department-level protocols now emphasize gross decontamination at the scene, separate storage of contaminated gear, and regular gear washing to reduce dermal carcinogen absorption.
• Cardiovascular screening: NFPA 1582 (Standard on Comprehensive Occupational Medical Program for Fire Departments) provides guidance on medical evaluations including cardiac screening for active firefighters.

Sources

• NFPA: Firefighter Fatalities in the United States in 2024, National Fire Protection Association, 2024
• CDC/NIOSH: Preventing Fire Fighter Fatalities from Cardiovascular Events, NIOSH Bulletin, cdc.gov/niosh
• Kales SN et al.: Extreme sacrifice: sudden cardiac death in the US Fire Service, PMC/NIH (PMID: 23864698)
• Kales SN et al.: Duty-related risk of sudden cardiac death among young US firefighters, PMC/NIH (PMC7811883)
• Daniels RD et al.: Cancer risk and mortality among firefighters: a meta-analytic review of 38 studies, PMC/NIH (2023)
• IARC Monographs Vol. 132: Occupational Exposure as a Firefighter, International Agency for Research on Cancer, 2022
• USFA: Firefighter Fatalities in the United States, U.S. Fire Administration, usfa.fema.gov

For broader data on the U.S. fire service, see our State of Firefighting 2026 Annual Report. For career preparation resources, see our Firefighter Salary Calculator and CPAT Training Timer.