Thick, toxic haze from Canadian wildfires is smothering major US cities, plunging millions into a regional health crisis as a stubborn heat dome locks pollution near the ground. The massive plumes, originating from over 800 active fires across Canada, have sent air quality index (AQI) levels to 'hazardous' heights across the Midwest and Northeast, with the smoke forecast to drift further south into the Mid-Atlantic through Friday.
A persistent 'heat dome' over the central and eastern regions has trapped the pollution close to the ground, turning what might have been a distant problem into an immediate health concern for millions of people living hundreds of miles from the flames.
