Air quality alerts are in effect on Tuesday in 10 states as toxic smoke from hundreds of wildfires burning in Canada continues to waft into the United States, creating hazy, gray skies over major metropolitan areas, including New York City.

Air quality alerts are in effect in the Philadelphia area, fueled by smoke from wildfires that are burning thousands of miles away.

Smoke from wildfires burning in Canada has caused air quality alerts for parts of New York state, including New York City.