Spatial Variations and Health Implications of Resuspended Road Dust Particulate Matter

CHEOL H. JEONG, Cuilian Fang, Eeman Abdulkadir, Nathan Hilker, Taylor Edwards, Greg J. Evans, SOCAAR, University of Toronto

     Abstract Number: 329
     Working Group: Urban Aerosols

Abstract
Non-tailpipe particulate matter (NTP), including road dust and brake/tire dust, are of increasing interest due to their potential impact on air pollution as efforts to reduce tailpipe emissions and promote electrification become more stringent. We investigated spatial variations of NTP across different types of roads and neighborhoods to understand population exposure and its contribution to ambient particulate matter (PM). Trace metals and oxidative potential (OP) analysis were conducted to infer NTP's impact on human health.

Mobile measurements using an electric vehicle equipped with high-time resolution instruments were conducted to measure PM_2.5, PM₁₀, the metal components of PM_2.5, ultrafine particles, black carbon, and carbon dioxide. Tandem sampling lines were mounted on the rear window and wheel-well area to measure PM resuspended from the road surface. Extensive mobile sampling was conducted to explore spatial variability in the concentrations of resuspended PM across residential and arterial roads, highways, and in school areas located near industrial, commercial, highway, and green space areas. The effectiveness of street sweeping equipped with vacuuming, blooms, and water spraying capabilities in reducing ambient and resuspended PM levels was also evaluated.

Resuspended road dust PM exhibited distinct spatial variations, with higher dust loadings in local school streets than on major roads and highways. Nearby construction, renovation, and landscaping activities likely caused the increase in resuspended road dust, rather than land use zoning near the neighborhoods. More targeted strategies should be developed to mitigate the impact of resuspended road dust around schools. Furthermore, positive correlations were observed between OP assays and trace metals identified in NTP, suggesting higher redox activity with NTP leading to OP values much higher than those found in local ambient samples.