The Illinois Environmental Protection Agency has issued an air quality alert for the entire state through Sunday night as a result of smoke again blowing in from Canadian wildfires.
The smoke was expected to begin sweeping through Illinois from the northwest Saturday afternoon, according to the National Weather Service.
People sensitive to poor air quality or who have a chronic respiratory issues were urged to limit outdoor activity.
The wildfire smoke brings a toxic brew of microscopic contaminants known as particulate matter 2.5.
Wearing N-95 or KN-95 masks can help filter out the pollutants.
Smoke from the Canadian wildfires made the air quality in Chicago “very unhealthy” June 27 and June 28, and Chicago had the worst air quality among big cities in the world on June 27.