Polycyclic Aromatic Hydrocarbons (PACs) are naturally occurring chemicals produced when hydrocarbons such as coal, gas, or wood burn. PAHs are classified as reasonably anticipated to be human carcinogens by the National Toxicology Program 14th Report on Carcinogens. Benzene is a commonly used solvent in industry that is also present in the smoke from burning wood and other materials. Benzene is a known human carcinogen classified by the International Agency for Research on Cancer as Group 1: Carcinogenic to humans. Exposure to PAHs and benzene is an occupational health concern regarding firefighters' health and wellness. Both PAHs and benzene concentrations are high in the smoke of burning structures and wildland fire smoke.

A study published in the Journal of Exposure Science and Environmental Epidemiology found that firefighters wearing full turnout gear and self-contained breathing apparatus (SCBA) still absorbed PAHs and benzene while fighting fire during residential structure burns. Because structural firefighters wear SCBA while fighting fires, it’s unlikely they were exposed to PHAs and benzenes through inhalation. Dermal exposure absorption is most likely. Another important finding of the study was that firefighters had elevated levels of PAH in their bodies compared to the general population even before going in to fight the fire for the research study. Suggesting that firefighters are continually exposed to PAHs as part of their jobs. The half-life of PAHs in the body is variable depending on the type of PAH and route of exposure. Overall the study results inform the fire service and medical community that firefighters are likely continually exposed to PAHs and benzene while fighting fire.

References:

Fent, K.W., Toennis, C., Sammons, D. et al. Firefighters’ absorption of PAHs and VOCs during controlled residential fires by job assignment and fire attack tactic. J Expo Sci Environ Epidemiol 30, 338–349 (2020). https://doi.org/10.1038/s41370-019-0145-2

Li, Z., Romanoff, L., Lewin, M. et al. Variability of urinary concentrations of polycyclic aromatic hydrocarbon metabolite in general population and comparison of spot, first-morning, and 24-h void sampling. J Expo Sci Environ Epidemiol 20, 526–535 (2010). https://doi.org/10.1038/jes.2009.41