Healthier Public Transit

Public transit is essential to the development of vibrant and sustainable cities. Sadly, our research has revealed elevated levels of exposure in both commuter trains and subways; the air quality in Toronto’s subway is among the worst in the world while commuter train passengers sitting near the engine can inhale high levels of diesel exhaust. Working in partnership with Metrolinx we showed that upgrading in-cabin filters can partially mitigate this exposure. 

Our research is now focused on developing a more fundamental understanding of the sources and removal mechanisms of particles in subways and trains. This knowledge is needed to support the changes in technology required for even more effective mitigation. We are also pursuing knowledge needed to better assess the potential health impact of the daily exposure of commuters. We are collecting data needed to estimate the individual exposures of commuters across commutes of differing distances and duration. At the toxicological level we are exploring how particles in subways and commuter trains differ from ambient particles which serve globally as the basis for most population exposure guidelines.


  • Van Ryswyk, K.; G.J. Evans, R. Kulka, L. Sun, K. Sabaliauskas, M. Rouleau, A. Anastasopolos, L. Wallace, S. Weichenthal “Commuting exposures to particulate air pollution in three Canadian bus transit systems: The Urban Transportation Exposure Study” Accepted J. Environ. Epi. Exp. Sci. DOI:10.1038/s41370-020-0242-2 Jun 2020 (2020)
  • Jeong, C-H., A. Traub, G. J. Evans. “Exposure to ultrafine particles and black carbon in diesel-powered commuter trains” Atmos. Environ. 155 46-52 2017.
  •  Van Ryswyk K., A. Anastassopolos, G. Evans, L. Sun, K. Sabaliauskas, R. Kulka, L. Wallace, S. Weichenthal. “Metro Commuter Exposures to Particulate Air Pollution and PM2.5-associated Elements in Three Canadian Cities: The Urban Transportation Exposure Study” Environ Sci & Technol.51(10), 5713–5720, 2017.