AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
New Insights into the Health and Climate Impacts of Boreal Wildfires
SARAH STYLER, Ming Lyu, Iris Chan, Nianci Zhang, Matthew S Ross, Cora J. Young, Daniel K Thompson, University of Alberta
Abstract Number: 797 Working Group: Biomass Combustion: Emissions, Chemistry, Air Quality, Climate, and Human Health
Abstract Over the past three summers, the Fort McMurray wildfire and wildfires across British Columbia released significant amounts of smoke and ash into the atmosphere, which resulted in substantial air quality reductions across western Canada. Wildfire ash contains toxic polycyclic aromatic hydrocarbons (PAH), which are known to undergo a variety of transformations on environmental surfaces. Here, we investigate the light- and ozone-mediated loss of PAH at the surface of ash samples obtained from the Fort McMurray wildfire. Since the toxicity of PAH ozonation products is often greater than that of the parent compounds, these experiments provide insight into the long-term health impacts of fires at the wildland–urban interface.
A major contributor to the particulate matter component of wildfire emissions is brown carbon (BrC), a class of light-absorbing organic carbon that can affect climate by altering Earth’s radiative balance. Although many studies have investigated the composition and properties of BrC, comparatively few studies have focused specifically on characterizing BrC produced from boreal wildfires. Here, we use size-exclusion chromatography with diode-array UV-Vis absorption detection to study the light-absorbing properties of particulate matter produced via combustion of boreal peat samples obtained in northern Alberta. We find that the composition and optical properties of fresh boreal peat BrC differ substantially from aged ambient wildfire BrC and also vary substantially with peat moisture content and sampling depth. Together, these results highlight the importance of performing experiments under realistic combustion conditions, and help to bridge lab studies of fresh BrC with field measurements of aged BrC.