Wildfire Smoke Toxicology and Health

Abstract

With wildfires increasing in activity in the Western United States and around the world, there is an immediate need to understand the toxic effects of the smoke. This chapter will provide a background of toxicology and apply principle concepts such as dose, duration and frequency to help define the potential effects of smoke exposure. Characteristics that influence toxicity will be discussed, which include particle size, source and temperature and the mixture of chemical constituents. An overview of the routes of exposure, mechanisms of action, toxicokinetics and the role of the immune system will all be covered.The importance and mutual benefits of in vitro, ex vivo and in vivo studies will be discussed. Finally, the chapter concludes by outlining knowledge gaps and research needs.

Health Effects of Wildfire Smoke Exposure

“…Wildfires emit a mixture of particles and gaseous pollutants that are known to negatively impact human health, including particulate matter (PM), carbon monoxide, nitrogen oxides, and volatile organic compounds (7)(8)(9)(10). Depending on the materials burned, heavy metals like lead and mercury can also be emitted.…”

Health effects of wildfires

“…Wildfires emit a mixture of particles and gaseous pollutants that are known to negatively impact human health, including particulate matter (PM), carbon monoxide, nitrogen oxides, and volatile organic compounds. 22,[31][32][33] Ground-level ozone can form secondarily through photochemical reactions. Depending on the materials burned, heavy metals like lead and mercury can also be emitted.…”

“…Wildfire-specific PM likely has a different toxicological profile from PM originating from other sources; 31,33 however, the relative toxicity of wildfire derived PM compared to PM from other sources remains uncertain. The amount and composition of pollution emitted from a specific fire varies depending on the fire's size, temperature of combustion, materials burned (e.g., grasses, tree species, buildings, vehicles), distance the smoke has traveled, and environmental conditions like wind speed, temperature, and humidity.…”

“…The amount and composition of pollution emitted from a specific fire varies depending on the fire's size, temperature of combustion, materials burned (e.g., grasses, tree species, buildings, vehicles), distance the smoke has traveled, and environmental conditions like wind speed, temperature, and humidity. [32][33][34]…”

“…It is likely that the mechanisms parallel those established in the broader air pollution literature, namely: oxidative stress and inflammation, impaired nervous system function, vascular dysfunction, direct damage when particulates and chemicals enter the bloodstream, and epigenetic alterations, among others. 33,70,99,100…”