Analysis: What a California gas leak can teach us about air purifiers in schools There is a growing body of research drawing a direct link between the physical conditions of school buildings and students' performance. Author of the article: Aaron Derfel • Montreal Gazette Publishing date: Apr 06, 2021 • 2 hours ago • 3 minute read • The EMSB showed off their newly installed air purifiers at Pierre Elliott Trudeau elementary school in Montreal on Monday January 11, 2021. The HEPA filter hangs from the wall in the background while principal Tanya Alvarez takes over a class at the elementary school. Photo by Dave Sidaway /Montreal Gazette files Article content