Traffic Related Air Pollution

Living near major roadways has been identified as a risk factor for a wide range of adverse health outcomes. One third of Canadians, over ten million people, live close enough to a major road to be potentially at risk.

Over the last five years we led federal and provincial partners in a study traffic related air pollution. We found that diesel trucks, not cars, are contributing most of some key air pollutants, producing excessive levels near roads with heavy trucking activity. The Ontario Government used our findings as the basis for a new policy; they will redirect Ontario’s Drive Clean program from cars to monitoring truck emissions. Our analysis also revealed that non-tailpipe emissions from brakes and tires have dramatically increased, recently overtaking tailpipe emissions of particles. Our study will be extended to create a national network of near road monitoring sites.  

We are currently exploring ways to better identify and understand where, when and how Canadians are being exposed to traffic related air pollution, along with opportunities to reduce this exposure.


  • E. Dabek-Zlotorzynska, V. Celo, L. Ding, D. Herod, C. Jeong, G.J. Evans, N. Hilker “Characteristics and sources of PM2.5 and reactive gases near roadways in two metropolitan areas in Canada” Accepted Atmos. Environ. 218 Sept. 2019
  • Hilker, N, J.M. Wang, C-H. Jeong, R. M. Healy, U Sofowote, J.Debosz, Y. Su, M. Noble, A. Munoz, G. Doerksen, L. White, C. Audette, D. Herod, J. R. Brook, G. J. Evans “Traffic-related air pollution near roadways: discerning local impacts from background” Atmos. Measure Tech. 12 5247-5261, 2019.
  • Wang, J.; C-H. Jeong, N. Hilker, R. Healy, U. Sofowote, J.  Debosz, Y. Su, M. McGaughey, G. Doerksen, T. Munoz, L. White, D.  Herod, G.J.  Evans “Near-Road Air Pollutant Measurements: Accounting for Inter-Site Variability using Emission Factors” Env Sci Technol 52(16) 9495-9504, 2018 https://10.1021/acs.est.8b01914.
  • Wang, J., C-H. Jeong, N. Zimmerman, R. M. Healy, N. Hilker, G.J. Evans. “Real-World Emission of Particles from Vehicles: Volatility and the Effects of Ambient Temperature” Environ Sci & Technol 51(7), 4081-4090, 2017 https://doi:10.1021/acs.est.6b05328.