Source: https://montrealgazette.com/news/local-news/with-better-awareness-of-aerosols-mask-wearing-shouldnt-end-soon-experts-say

Canada’s chief public health officer, Dr. Theresa Tam, issued a series of tweets and public health messages last weekend detailing how COVID-19 is spread via fine aerosols lingering in the air. She likened it to a cloud of second-hand smoke that floats in a room unseen, with the potential to contaminate inhabitants long after the person who brought in the disease has departed.
For many in the scientific community, the announcements came as validation of arguments they’ve made for months that health officials have downplayed the importance of transmission via aerosols.