CENTRAL ILLINOIS (WCIA) — Central Illinois is still under an air quality alert as of Monday morning as ground-level ozone persists and is joined by smoke from Canadian wildfires.

The Illinois Environmental Protection Agency announced on Friday that it was issuing an air quality forecast of “orange” or “unhealthy for sensitive groups.” People with respiratory or pulmonary disorders, they said, could experience coughing or shortness of breath under this alert.

Officials added that the causes of this ozone are emissions of nitrogen oxides and volatile organic compounds reacting in the presence of sunlight. But as of Monday, a new factor is entering the mix: smoke from wildfires in Quebec being carried by a cold front into the Midwest.

As a result, Illinois remains under an orange level air quality forecast to start the week.

The IEPA advised that people in general are advised to use caution whenever outdoors, staying cool and limiting their physical activity. They can also reduce air pollution by taking public transportation, avoiding the use of gasoline-powered equipment and reducing energy demands.

Sensitive individuals are advised to take special precautions and follow their physician-prescribed regimen.