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Role of Fuel and Combustion Conditions on the Chemistry and Cardiopulmonary Toxicity of Smoke from Wildland Fires
Citation:
Gilmour, Ian. Role of Fuel and Combustion Conditions on the Chemistry and Cardiopulmonary Toxicity of Smoke from Wildland Fires. American Public Health Association (APHA) Annual Meeting, San Diego, CA, November 10 - 14, 2018.
Impact/Purpose:
Overall, our findings suggest that wildland fire smoke in the regions of peat and eucalyptus fuels may induce greater health effects than smoke from oak fires, and that on a mass basis, there is a greater health risk from flaming smoke compared to smoldering emissions.
Description:
Smoke from wildland fires as well as from prescribed, agricultural and domestic wood burning is a significant air quality and public health issue. We have previously assessed lung toxicity of biomass smoke particulate matter (PM) from flaming versus smoldering phases of five different fuels (oak, peat, pine, pine needles, and eucalyptus) and reported that the greatest lung toxicity was for eucalyptus smoke (smoldering and flaming phases) or peat smoke (flaming phase), while the least lung toxicity was for oak smoke (smoldering and flaming phases). We have since conducted inhalation exposures on a subset of the biomass fuels (oak, peat, and eucalyptus) under smoldering and flaming conditions. Mice were exposed to the biomass smoke for 1 hour/day for 2 days and then assessed for lung toxicity at 4 and 24 h after the second exposure. The peat (flaming and smoldering) and eucalyptus (smoldering) smoke significantly induced lung toxicity (neutrophil influx) at 4 h which was further increased at 24 h after exposure to the peat (flaming) smoke. No responses were observed at any of the oak smoke exposure conditions. We found good correlation of the lung toxicity potencies between the inhalation and aspiration methods suggesting that the aspiration exposure method provides a comparable prediction of pulmonary toxicity from biomass smoke inhalation. Overall, our findings suggest that wildland fire smoke in the rich regions of peat and eucalyptus fuels may induce greater health effects than smoke from oak fires, and that on a mass basis, there is a greater health risk from flaming smoke compared to smoldering emissions. Additional work is examining whether exposure preferentially affects individuals with pre-existing disease such as asthma and diabetes and if photochemical aging of wildfire smoke increases toxicological responses through alterations in chemistry. (This abstract does not represent EPA policy)