Smoke from ongoing wildfires in Canada is impacting the air quality in states across the Midwest and Northeast of the U.S.
Officials issued air quality alerts on Sunday and Monday for parts of Delaware, Maine, Massachusetts, Michigan, New Hampshire, New York, Pennsylvania, Vermont and Wisconsin.
The Air Quality Index (AQI), which is the federal measurement system used to calculate air pollution and hazards, had parts of the states in those regions at levels well over 100 — which is depicted as the color orange on the map below means "sensitive groups" such as children, the elderly or pregnant people should spend less time outside.
Some regions even measured an AQI level over 150, depicted in red on the map. It means everyone should avoid physical activity outdoors.
According to Natural Resources Canada, there are than 200 fires burning across the country and dozens of them are out of control.
Unhealthy air can irritate your respiratory system, reduce lung function, damage cells that line the lungs, make lungs more susceptible to infections, aggravate asthma or even cause permanent lung damage in severe cases, according to the U.S. Environmental Protection Agency.
When air quality is poor, experts say you should stay indoors as much as possible, keep your windows closed, use the recirculate settings on your HVAC system and wear an N95 mask if you must go outside.
