Environment Canada research scientists say the COVID-19-induced economic slowdown is leading to cleaner air in many Canadian cities.
Chris McLinden and Debora Griffin say remote satellite sensors show significant drops in the nitrogen dioxide pollution hovering above many major cities like Toronto, Montreal and Edmonton.
McLinden says on average Canada's big cities have seen air pollution fall by about one-third.
Health Canada last year estimated that more than 14,000 Canadians die prematurely each year because of air pollution.
Miriam Diamond, a professor of earth sciences at the University of Toronto, says even a temporary drop in air pollution can have a positive impact on human health, especially in a pandemic when people with existing respiratory illnesses will feel better just by breathing cleaner air.
McLinden also says the data he and Griffin are collecting right now is an unexpected real-life experiment that is going to help improve modelling for where air pollution is coming from and how best it can be improved over the long term.