Environmentally Persistent Free Radicals, Reactive Oxygen Species, and Oxidative Potential of Fine Particulate Matter Generated From Burning Natural Fuels and Building Materials
BRADLEY H. ISENOR, Hongru Shen, Amanda Hanashiro Moraes, Ginny Marshall, Jason S. Olfert, Ran Zhao, Jonathan Abbatt, Arthur W. H. Chan, University of Toronto
Abstract Number: 387
Working Group: Burning Questions of Aerosol Emissions, Chemistry, and Impacts from Wildland-Urban Interface (WUI) Fires
Abstract
Wildfires are expected to become more prevalent with climate change and as a consequence, their contribution to global fine particulate matter (PM2.5) emissions and adverse health outcomes is expected to rise. The PM2.5 emitted from wildfires is highly complex as its composition can vary based on an assortment of burning conditions, such as the types of biomass burned, moisture level, and combustion type. This complexity has made understanding the harm associated with wildfire PM2.5 challenging at a chemical level. With increasing frequency of fires at the wildland-urban interface (WUI), it is important to not only assess the potential health implications of burning natural fuels when considering the health impacts of wildfire PM2.5, but also those arising from the burning of building materials, whose health effects are even less understood. Here we investigate the potential health impacts of PM2.5 generated from the burning of nine natural fuels and four plastic building materials through the lens of oxidative potential (OP) using the dithiothreitol assay. Additionally, electron paramagnetic resonance spectroscopy is used to measure environmentally persistent free radicals (EPFR) and reactive oxygen species (ROS). Several replicates of each fuel type were burned during the Biomass Burning Canada fire lab campaign in the summer of 2024 and were accompanied by a comprehensive suite of online and offline measurements to connect aerosol composition with EPFR, ROS, and OP measurements. Given the obvious differences in the chemical composition of fuel-types burned, PM2.5 from natural fuels and building materials is expected to have considerably different compositions and thus different OP and radical profiles, even within the two classes. In this presentation, an analysis of EPFR, ROS, and OP for all fuels burned will be presented with an emphasis on building fuels and how they compare to natural fuels. Results from this work will improve understanding of the potential harm of wildfires under different burning conditions and those that reach the WUI.