Although the majority of wildfires are occurring in western Canada, smoke from these fires has been drifting eastward, impacting air quality in areas around the Great Lakes and the U.S. Northeast, shows AirNow, the Environmental Protection Agency's interactive air quality map.

While the smoke may cloud your vision of the sky or ruin a day at the beach on this week's warmest days of the season so far, it is more than just a nuisance. All across the U.S., the smoke is causing poor air quality, which can cause health effects from mild symptoms in the healthy to dangerous risks for sensitive groups.