Wildfires continue to ravage the Alberta countryside today. Thousands of people have been evacuated from their homes as firefighters combat what has been described as an "out-of-control" blaze.\nAs we reported earlier this week, however, the effects of the fires are much farther reaching. Smoke from Alberta has now spread across the continent. Though the smoke is not always visible, invisible pollutants, known as "particulate matter" have negative health effects, nonetheless.\n"Inhalation of particulate pollution can have adverse health impacts, and there is understood to be no safe threshold below which no adverse effects would be anticipated," explains the UK Department for Environmental Affairs.\nA map from FireSmoke Canada, a collaboration between the provincial and federal governments, displays the extent of particulate matter from the smoke. The map measures PM2.5 levels — "the mass per cubic metre of air of particles with a size (diameter) generally less than 2.5 micrometres."\nFireSmoke Canada\nThe screenshot above from the moving map shows the extent of particulate mater on May 31st by 20:00 UTC, or 16:00 EST.\nREAD ALSO: Montreal Just Broke A 142 Year Rainfall Record\nKelly Sonnenburg, a meteorologist for The Weather Network, tweeted out satellite footage that shows visible smoke over Ontario and western Quebec.\nEarly morning look at visible satellite reveals the wildfire smoke over parts of Ontario and Quebec. #onwx pic.twitter.com/D08wUZwgOf— Kelly Sonnenburg TWN (@kellysonnenburg) May 31, 2019\nNote, however, that while Environment Canada has issued an air quality alert for part of Ontario, there is currently no similar alert in Quebec. The Ontario alert concerns the Sandy Lake – Pikangikum area.\nAlmost the entirety of Alberta, meanwhile, is under an air quality alert.\nEnvironment Canada\nStay tuned for more information about the wildfires in western Canada and the spread of particulate matter from smoke across the continent.\nFollow the FireSmoke Canada website here for updates.\nYou can also follow Kelly Sonnenburg on Twitter here.\nAlways stay apprised of alerts and warnings from Environment Canada here.