What is the risk of cancer in firefighters due to occupational exposure to carcinogens?

Cancer Risk in Firefighters

Firefighters face a significantly elevated risk of multiple cancers due to occupational exposure to carcinogens, with the most robust evidence showing increased incidence of colon, rectal, prostate, testicular, bladder, thyroid, pleural cancers, and malignant melanoma.

Magnitude of Cancer Risk

The most comprehensive meta-analysis demonstrates firefighters have statistically significant elevated cancer incidence across multiple sites 1:

• Colon cancer: 14% increased risk (SIRE 1.14; 95% CI 1.06-1.21) 1
• Rectal cancer: 9% increased incidence (SIRE 1.09; 95% CI 1.00-1.20) and 36% increased mortality (SMRE 1.36; 95% CI 1.18-1.57) 1
• Prostate cancer: 15% increased risk (SIRE 1.15; 95% CI 1.05-1.27) 1
• Testicular cancer: 34% increased risk (SIRE 1.34; 95% CI 1.08-1.68) 1
• Bladder cancer: 12% increased risk (SIRE 1.12; 95% CI 1.04-1.21) 1
• Thyroid cancer: 22% increased risk (SIRE 1.22; 95% CI 1.01-1.48) 1
• Pleural cancer (mesothelioma): 60% increased risk (SIRE 1.60; 95% CI 1.09-2.34) 1
• Malignant melanoma: 21% increased risk (SIRE 1.21; 95% CI 1.02-1.45) 1

Additional population-based studies confirm moderately elevated risks for brain cancer (SMOR 1.90; 95% CI 1.10-3.26) and colon cancer (SMOR 1.36; 95% CI 1.04-1.79) 2.

Specific High-Risk Cancer Sites

Head and Neck Cancers

Professional municipal firefighters with light or no smoking history face an 8-fold increased risk of hypopharyngeal and laryngeal squamous cell carcinoma (OR 8.06; 95% CI 1.74-37.41), with risk increasing 2.1-fold per decade of service (OR 2.10; 95% CI 1.06-4.14) 3. This finding is particularly striking because it persists even after controlling for smoking and alcohol—the two major risk factors for head and neck cancer 3.

Carcinogenic Exposures

Polycyclic Aromatic Hydrocarbons (PAHs)

Firefighters are exposed to multiple PAH carcinogens including benzo[a]pyrene, 7,12-dimethylbenzo[a]anthracene, and 3-methylcholanthrene 4. These compounds are detected on:

• Body surfaces: jaw, neck, hands 4
• Personal protective equipment: helmets, clothing 4
• Work environments: fire stations, engines, offices 4

Cancer slope factor calculations indicate markedly elevated cancer risk from these exposures, with skin absorption appearing to be the primary exposure route 4.

Broader Occupational Carcinogen Exposure

According to NCCN guidelines, occupational exposure to lung carcinogens (arsenic, chromium, asbestos, nickel, cadmium, beryllium, silica, diesel fumes, coal smoke, and soot) confers a mean relative risk of 1.59 for lung cancer 5. Firefighters encounter many of these agents in fire smoke and combustion products 6.

The American College of Chest Physicians notes that occupational exposures account for approximately 10% of lung cancer burden in industrialized nations, with cigarette smoking potentiating the carcinogenic effects of workplace exposures 5.

Synergistic Risk Factors

Smoking Interaction

Among firefighters exposed to occupational carcinogens, smokers have substantially greater cancer risk than nonsmokers 5. This multiplicative effect is well-established for occupational lung carcinogens 5.

Additional Occupational Factors

Beyond direct carcinogen exposure, firefighters face additional cancer risk factors 6:

• Shift work (disrupts circadian rhythms) 6
• Sedentary behavior during station time 6
• Fire service food culture (often high-calorie, processed foods) 6

Lifestyle Risk Factors

Obesity, tobacco use, excessive alcohol consumption, poor diet, inadequate physical activity, and short sleep duration are associated with increased risk of firefighting-associated cancers 6.

Clinical Implications and Surveillance

High-Priority Screening Considerations

Given the elevated cancer risks, firefighters warrant enhanced surveillance for:

1. Colorectal cancer screening: Consider earlier initiation given 14-36% increased risk 1, 2
2. Prostate cancer screening: Discuss risks/benefits given 15% increased incidence 1
3. Skin cancer surveillance: Annual dermatologic examination for melanoma (21% increased risk) 1
4. Testicular self-examination education: 34% increased risk, particularly in younger firefighters 1

Lung Cancer Screening

While not specifically addressed for firefighters in current guidelines, those meeting standard high-risk criteria (age 55-74 years, ≥30 pack-year smoking history, quit <15 years ago) should undergo low-dose CT screening 5. Consider screening in firefighters with lower smoking thresholds given their additional occupational carcinogen exposure (mean RR 1.59 for occupational lung carcinogens) 5.

Prevention Strategies

Occupational Exposure Reduction

Immediate post-fire decontamination is critical to minimize skin absorption of PAH carcinogens 4. This includes:

• Washing exposed skin surfaces (face, neck, hands) immediately after fire exposure 4
• Proper cleaning and maintenance of personal protective equipment 4
• Avoiding contamination of fire station living areas 4

Lifestyle Modification

Given the synergistic effects of smoking with occupational carcinogens, smoking cessation is paramount 5. Physical activity may reduce lung cancer risk by 13-30% 5, though this benefit must be weighed against potential residual confounding.

Critical Caveats

• Most cancer risk data come from cohort and registry studies that may not fully adjust for smoking and alcohol consumption 3
• The latency period for occupational cancers means current firefighters may face different risks than historical cohorts due to changes in equipment and practices 6
• Individual risk varies substantially based on duration of service, specific exposures, use of protective equipment, and personal risk factors 3, 1