Thick smoke from raging Canadian forest fires has covered a swath of North America in unhealthy air, disrupting everything from air travel to Broadway shows and bringing unsettling reminders of the Covid-19 pandemic.
Authorities issued health warnings to millions of people in the eastern US and Canada on Wednesday as a cloud fed by hundreds of northern forest fires swept south, plaguing heavily populated areas from Ottawa to Washington, DC.
In New York City, the air quality ranked as the worst of any major urban area in the world on Wednesday, topping New Delhi, according to the IQAir World Air Quality index.
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