10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Chemistry and Photochemistry at the Surface of Tomorrow's Urban Particulate Matter
SARAH STYLER, Maya Abou-Ghanem, Stephanie Schneider, Zhihao Chen, Ming Lyu, Brett Wickware, Jonathan Abbatt, Patrick Milner, Arthur Duarte de Marins Costa, Jeffery Kwasny, University of Alberta
Abstract Number: 1659 Working Group: Aerosol Chemistry
Abstract In both Canada and the United States, the largest anthropogenic source of primary PM2.5 is dust resuspension from paved and unpaved roads. Since road dust contains many toxic species, including heavy metals and polycyclic aromatic hydrocarbons, many studies have focused on its composition and potential health effects. By contrast, little is currently known regarding its atmospheric reactivity.
We have previously shown that illumination of urban road dust leads to the production of singlet oxygen (1O2), an important environmental oxidant. Here, we report spatial and seasonal variations in 1O2 production by road dust, and thereby provide new insights into the relationship between road dust composition and photochemical reactivity. We also present results from coated-wall flow tube investigations of ozone and NO2 uptake by winter street sweepings and brake wear particles.
As vehicle exhaust emission regulations become more strict in coming years, the relative contribution of road dust and other non-exhaust emissions to urban PM loadings will increase. Our work provides evidence that photochemistry at the surface of road-derived PM can influence both the lifetimes of pollutants present at the dust surface and the composition of the surrounding atmosphere.