CHICAGO — The smoke from the wildfires in Canada have left parts of the United States under an air quality alert.

Some smoke and haze is expected in Chicago and parts of Illinois on Friday, but most of the heavier smoke is expected to continue in the east and as far south as North Carolina.

An air quality action day was issued on Wednesday, Thursday and Friday for all of Indiana due to the smoke.

According to the Indiana Department of Environmental Management, there are high levels of fine particles in Friday’s forecast.

IDEM said the particles include microscopic dust, soot and liquid that can settle into the lungs and can be hard to exhale.

The National Weather Service said people with chronic respiratory illnesses should limit their time outdoors.

Air quality alerts have been issued in 24 states.

Earlier this week, New York City and parts of the northeast, people were urged to stay indoors because of the hazardous conditions.

Millions of residents could see that for themselves Thursday. The conditions sent asthma sufferers to hospitals, delayed flights, postponed ballgames and even pushed back a White House Pride Month celebration. The fires sent plumes of fine particulate matter as far away as North Carolina and northern Europe and parked clumps of air rated unhealthy or worse over the heavily populated Eastern Seaboard.

At points this week, air quality in places including New York, the nation’s most populous city, nearly hit the top of the U.S. Environmental Protection Agency’s air-pollution scale. Local officials urged people to stay indoors as much as possible and wear face masks when they venture out.

The Associated Press contributed to this report.