Researchers have identified a knowledge gap between what scientists have discovered about wildfire smoke and the practical information available to frontline crews.
The study provides an overview of both published science and organisational reports and standards for minimizing exposure and mitigating health risks for firefighters. The review was conducted by Australian and US researchers with results relevant to all firefighters in hot and smoky environments.
Bushfire smoke is a complex mixture of hazardous substances. Inhalation poses acute and chronic health risks to firefighters, including respiratory and cardiovascular effects and potential risk for certain cancers.
But any health-risk analysis is made complex by the great variation in exposure levels that are influenced by vegetation type, fire behaviour and weather, and the varied behaviours and activities of individuals. Hence the need identified by the paper to distil the current science into practical guidelines for firefighters.
The review emphasizes the importance of personal protective equipment (PPE), improved decontamination protocols, the need for real-time exposure monitoring and adequate exposure reduction policies.
The key takeaway is that firefighters face a “total exposure” risk, and the danger doesn’t stop when they are no longer breathing in smoke, explains lead author Dr Maximilien Desservettaz, a Research Fellow from the University of Wollongong.
“A critical finding we highlight is that the skin is a major and under-appreciated pathway for toxic, carcinogenic chemicals to enter the body. The intense heat and heavy sweating from firefighting can dramatically increase the skin’s permeability. Our review of the science shows that sweat can act like a solvent, pulling carcinogens like PAHs (polycyclic aromatic hydrocarbons) from the soot on their gear and skin into their bodies,” said Dr Desservettaz.
“This is immediately useful for firefighters because it provides the scientific “why” behind rapid and thorough decontamination. It confirms that washing your skin and properly cleaning your gear isn’t just about cleanliness, it’s a critical health and safety procedure to stop that ongoing chemical exposure.”
The paper also clarifies the limitations of PPE. For instance, the researchers confirm that the P2/N95-style masks common in wildland firefighting are excellent for particles but provide zero protection against the many toxic gases in smoke, such as benzene, formaldehyde, and hydrogen cyanide.
Also, PPE may inadvertently introduce secondary hazards for fire fighters. Face masks worn during times of intense physical exertion in hot environments can restrict breathing and potentially increase fatigue. Masks may also restrict peripheral vision and impede clear communication. PPE clothing with chemical layers for high thermal protection may contribute to heat stress by trapping body heat and sweat.
“Ultimately, this research provides the evidence base for firefighters and agencies to make informed risk-management decisions. It validates the concerns firefighters have had for years and provides a scientific basis for enhancing safety protocols, from consistent PPE use to, most critically, effective after-fire decontamination.”
The paper is part of a broader study funded by the NSW Bushfire and Natural Hazards Research Centre. The researchers are now working with the peak body for fire agencies in Australia, the Australasian Fire and Emergency Service Authorities Council, to translate these findings into practical educational materials.
“Addressing firefighter concerns: unravelling the complexities of bushfire smoke composition and toxicity” is published in the International Journal of Wildland Fire.
