Chicago Braces for Canadian Wildfire Smoke.

Smoke from the Canadian wildfires has caused air quality alerts in 24 US states, including an air quality action day in Indiana due to high levels of fine particles. While some haze is expected in Chicago and parts of Illinois on Friday, the heavier smoke is expected to continue in the east and as far south as North Carolina. People with chronic respiratory illnesses are advised to limit their time outdoors. The fires have sent plumes of fine particulate matter as far away as northern Europe and parked clumps of air rated unhealthy or worse over the heavily populated Eastern Seaboard.