Mortality in firefighters: extended follow-up of a Danish cohort, 1970–2021

Objectives: Firefighters face numerous occupational hazards that raise concerns regarding adverse health effects and mortality. Therefore, we conducted an updated evaluation of mortality in a cohort of Danish firefighters by adding 7 years of follow-up. Methods: The updated cohort comprised 11,888 male Danish firefighters, and the assessment of mortality spanned from 1970 through 2021. Data on vital status, emigration and mortality was retrieved from the Danish Civil Registration System and the Danish Register of Causes of Death. Standardized Mortality Ratios (SMRs) were calculated for the cohort, along with 95% confidence intervals (95% CI), utilizing a population of employees from the general working population as a reference. Results: For the firefighters, we observed lower overall mortality (SMR = 0.78; 95% CI: 0.74–0.82), while cancer mortality was even (SMR = 0.99; 95% CI: 0.92–1.08). Significantly reduced mortality was observed for mental disorders, conditions of the nervous system and sensory organs, pneumonia, non-traffic related accidents, suicide, as well as symptoms and ill-defined conditions. Mortality rates for most other causes were also reduced, including circulatory and respiratory diseases. However, higher mortality from specific cancers were observed, including cancer of the thyroid gland, kidney, urinary bladder and brain. Finally, we noticed a trend indicating a higher mortality rate among full-time firefighters when compared to their part-time counterparts. Conclusions: Our findings in a large cohort of Danish firefighters generally indicated a decrease in all-cause mortality as well as from most specific causes compared to other employees. However, slightly higher mortality rates were observed for certain cancers in full-time firefighters.