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.

The National Weather Service announced air quality alerts in 10 states Tuesday as smoke from the Canadian wildfires continues to spread across the U.S. border. The alerts come as the Canadian Interagency Forest Fire Centre lists 746 active fires Tuesday morning,

An air quality alert is in effect for all of Massachusetts as smoke from Canadian wildfires descends into the Boston area.