Smoky haze from Canada wildfires triggers New York flight chaos

Health alerts in dozens of states as New York City air quality rated worst in world

Hundreds of flights were delayed and dozens of public events cancelled across the eastern United States on Thursday as smoky haze caused by Canadian wildfires led to hazardous pollution.

Health officials in more than a dozen states warned millions of residents that spending time outdoors could cause respiratory issues due to the high levels of fine particulates in the atmosphere.

Forest fires continue to burn across Canada, which is enduring its worst-ever start to wildfire season. Thousands have been forced from their homes and about 9.4 million acres have already burned, roughly 15 times the 10-year average.