Human biomonitoring and risks of hazardous occupational exposure to polycyclic aromatic hydrocarbons in wildland fires: a critical review

The increase in global temperatures associated with climate change has intensified the frequency, duration, and severity of wildfires, resulting in exposure to a range of hazardous compounds, including polycyclic aromatic hydrocarbons (PAHs). The work of wildland firefighters involves exposure to several physical, chemical, and biological hazards. The present study evaluated the health effects of PAH exposure from wildfires on firefighters. A systematic literature review was conducted using the Web of Science, PubMed, Scopus, CINAHL, and Lilacs databases, covering the period from January 2019 to June 2025, according to PRISMA guidelines. Out of 766 papers retrieved, 16 met the inclusion criteria. Biomonitoring was employed to quantify the levels of biomarkers of exposure, specifically monohydroxylated PAHs (OH-PAHs), in most studies, and biomarkers of effect, such as biochemical or cellular changes, in over half of them. Most studies have indicated significant post-exposure increases (up to 12-fold) in urinary PAH metabolite levels, either during simulated burn training or actual wildfire events. The primary health effects observed were oxidative stress, increased DNA damage, and alterations in inflammatory markers and immunological cells. Both respiratory and dermal exposure routes are significant, with dermal absorption identified as a key pathway even when respiratory protection is used. However, there is no specific certified respiratory personal protective equipment (PPE) for use in wildfires. In consideration of these findings, it is recommended that specialized equipment be developed for forest firefighting to reduce smoke exposure. The review highlights the need to mitigate these risks as the workers presented a high body burden of PAHs, and current exposure limits may be insufficient. Further occupational exposure studies, particularly in under-researched, high-impact geographical regions, are crucial to guide the development of public health policies and enhance risk management strategies for wildland firefighters.