From the Cook County Department of Environmental Control:
Today, Wednesday, July 20, 2011, has been declared an Air Pollution Action Day. An Air Pollution Action Day is declared when weather conditions are such that levels of ozone/particulate matter are expected to be above the Unhealthy for Sensitive Groups category of the Air Quality Index
Persons with heart or respiratory ailments are advised to limit activities and remain indoors.
Participants in the Partners for Clean Air Program are requested to initiate their activities. The general public can help reduce ozone levels by limiting unnecessary driving, by using public transportation, by avoiding refueling, by avoiding the use of oil base paints and solvents, the use of charcoal lighter fluid and the excessive use of home energy.