As Canada grapples with one of the worst wildfire seasons in decades, heavy smoke was wafting into the American Midwest yesterday, a day after NASA said it had crossed the Atlantic Ocean all the way to Europe.
Canada is grappling with an exceptional outbreak of wildfires across the nation that has forced hundreds of people from their homes, raised concerns about global warming, and sent choking smoke down the East Coast of the United States, from New York City to Washington, and as far west as Minnesota.
How does the smoke affect the air quality in the American Midwest?
Canada's wildfires in Chicago, Detroit and Milwaukee, among other areas, were significantly worsening air quality. In Chicago, the Air Quality Index reached 209 by noon Tuesday, the worst reading in any major city in the world, according to Swiss air-quality technology firm IQAir.
In Green Bay, Wis., the index was 175, and in Grand Rapids, Mich., it soared to 255. A warning to people with respiratory conditions to take precautions is issued when a reading above 100 is listed on the index.