Bioaerosol Emissions from Prescribed Fires and Laboratory Burns

Wildfires emit a variety of gasses and particles into the atmosphere. Recent work has shown elevated bioaerosols associated with smoke plumes from biomass fires. Bioaerosols or aerosols composed of biogenic material (e.g. bacteria, fungi, pollen) are not well characterized in the atmosphere and the impact of their emissions from biomass fires remains uncertain. To help address this gap, in a laboratory setting, we performed controlled burns in a tube furnace using grass, leaf, and evergreen fuels at two temperatures (500C and 1000C) to understand the effect of smoldering and flaming temperatures on the amount and properties of bioaerosol particles emitted. We also sampled emissions from a prescribed fire in the Konza Prairie Grasslands. Bioaerosol particles were measured using Wideband Integrated Bioaerosol Sensor-NEO (WIBS-NEO, DMT). WIBS uses fluorescence excitations (280 and 370 nm) to detect (310-400 nm and 420-650 nm) bioaerosols which are then classified according to fluorescence behavior, size, and a shape parameter. Our preliminary analyses suggest that smoldering and flaming temperatures contribute to emitting different abundances, types, and shapes of bioaerosol particles. Additionally, the emitted bioaerosols from our various fuels have different properties. We will compare the properties of bioaerosol from our laboratory burns to emissions from prescribed fires and to background or non-fire impacted air masses.