As smoke from hundreds of Canadian wildfires continues to spread across large parts of North America, bringing hazardous air to tens of millions of people, outdoor activities are being canceled, businesses disrupted and vulnerable residents kept indoors as officials warn the unhealthy conditions will likely persist.
Air quality alerts were issued across more than 20 US states as smoke from wildfires burning in south-central Canada, northern Ontario and parts of Minnesota drifted south. About 109 million Americans across the midwest, mid-Atlantic and north-east experienced unhealthy air this week.
