INDIANAPOLIS (AP) — Indiana’s environmental agency issued a statewide air quality alert this week urging Hoosiers to slow down and take other steps as smoke wafts across the state from wildfires burning in the western U.S. and Canada.

The Indiana Department of Environmental Management said Wednesday it issued the air quality alert for Wednesday and Thursday because of microscopic smoke particles from the wildfires. That smoke has blanketed much of the continent, including thousands of miles away on the East Coast.

IDEM said it was encouraging Hoosiers to reduce how much time they spend outside doing various activities, and to avoid exercising near busy roadways. The agency was also urging people to avoid burning wood or making other unnecessary fires and to also avoid using gasoline-powered equipment or gas-powered recreational vehicles.

Growing research points to potential long-term health damage from breathing in microscopic particles of smoke, with millions of people potentially at risk far from where huge fires burn.