Canada's guidelines on how COVID-19 spreads still do not acknowledge the threat of infection through the air, despite other countries and international health organizations updating their stance on the issue.
As researchers around the world race to learn as much as possible about the novel coronavirus, many health agencies have concluded that it can be transmitted via aerosols — or microscopic airborne particles — yet Canada has not followed that lead so far.
It was originally believed the novel coronavirus spread only via large droplets, which fall and settle on the ground within a distance of two metres — prompting the recommendation to social distance and stay two metres away from others. But understanding of the virus has evolved, and it's now widely believed that it can also spread from smaller droplets that contain virus particles that can remain suspended in the air for a long time.
The World Health Organization came under fire in July after 239 scientists from 32 countries wrote an open letter calling on the United Nations agency to update its messaging on the risk of airborne transmission of the coronavirus.