Mutagenicity and Lung Toxicity of Smoldering vs. Flaming Emissions from Various Biomass Fuels: Implications for Health Effects from Wildland Fires

Abstract

Background:The increasing size and frequency of wildland fires are leading to greater potential for cardiopulmonary disease and cancer in exposed populations; however, little is known about how the types of fuel and combustion phases affect these adverse outcomes.Objectives:We evaluated the mutagenicity and lung toxicity of particulate matter (PM) from flaming vs. smoldering phases of five biomass fuels, and compared results by equal mass or emission factors (EFs) derived from amount of fuel consumed.Methods:A quartz-tube furnace coupled to a multistage cryotrap was employed to collect smoke condensate from flaming and smoldering combustion of red oak, peat, pine needles, pine, and eucalyptus. Samples were analyzed chemically and assessed for acute lung toxicity in mice and mutagenicity in Salmonella.Results:The average combustion efficiency was 73 and 98% for the smoldering and flaming phases, respectively. On an equal mass basis, PM from eucalyptus and peat burned under flaming conditions induced significant lung toxicity potencies (neutrophil/mass of PM) compared to smoldering PM, whereas high levels of mutagenicity potencies were observed for flaming pine and peat PM compared to smoldering PM. When effects were adjusted for EF, the smoldering eucalyptus PM had the highest lung toxicity EF (neutrophil/mass of fuel burned), whereas smoldering pine and pine needles had the highest mutagenicity EF. These latter values were approximately 5, 10, and 30 times greater than those reported for open burning of agricultural plastic, woodburning cookstoves, and some municipal waste combustors, respectively.Conclusions:PM from different fuels and combustion phases have appreciable differences in lung toxic and mutagenic potency, and on a mass basis, flaming samples are more active, whereas smoldering samples have greater effect when EFs are taken into account. Knowledge of the differential toxicity of biomass emissions will contribute to more accurate hazard assessment of biomass smoke exposures. https://doi.org/10.1289/EHP2200

In situ measurements of trace gases, PM, and aerosol optical properties during the 2017 NW US wildfire smoke event

“…3906 V. Selimovic et al: Regional wildfire smoke: trace gases, PM, and aerosol optical properties fraction of the global BB in the western US is responsible for a significant portion of US air quality impacts (Park et al, 2007;Liu et al, 2017;Wilkins et al, 2018;Zhou et al, 2018) and contributes to increasing health concerns. Wildfire smoke has been shown to have adverse respiratory and cardiovascular health effects, is associated with mortality and morbidity, and exhibits lung toxicity and mutagenicity (Le et al, 2014;Liu et al, 2015;Reid et al, 2016;Adetona et al, 2016;Kim et al, 2018). In some cases, long-range transport of biomass burning emissions can cause air quality standards to be exceeded hundreds or thousands of kilometers downwind of the fire source (Jaffe et al, 2013;.…”

Mapping Modeled Exposure of Wildland Fire Smoke for Human Health Studies in California

“…Because fine particulate air pollution (PM 2.5 ) is a multi-dimensional pollutant originating from a variety of sources, including wildland fire, there are gaps in our understanding of how exposure to wildland fire smoke impacts health. While wildfires produce high levels of air pollutants, the chemical signature differs from other source of ambient PM and shows differential toxicity for some endpoints [24][25][26][27]. Exposure scenarios differ as well, with substantially sharper peaks during wildfires [7].…”

Can Air Quality Management Drive Sustainable Fuels Management at the Temperate Wildland–Urban Interface?

“…This means that each operation carries the heavy transactional costs of negotiating with multiple land tenures, other stakeholders, and insurance providers [5]; (2) blunted effectiveness of prescribed fire during extreme fire weather, because reduced fuel loads do not limit wildfire spread in hot, dry, and windy conditions [6]; (3) shifting of the timing and/or number of days available for prescribed fire under a changing climate [7][8][9]; and (4) management of smoke pollution to minimize its public health impacts [10]. Of these drawbacks, the latter is putting increasing constraint on the use of prescribed fire as the adverse effects of smoke on human health become clearer [11][12][13][14].…”