...AIR QUALITY ALERT IN EFFECT UNTIL MIDNIGHT CDT TONIGHT... The Illinois Environmental Protection Agency has determined that an Air Pollution Action Day will be declared for the greater Chicago Metropolitan Area and is IN EFFECT UNTIL MIDNIGHT CDT TONIGHT. An Air Pollution Action Day is declared when weather conditions are such that widespread ozone and or particulate levels are expected to be at or above the Unhealthy for Sensitive Groups category of the Air Quality Index for multiple days. Ozone is expected to be the primary pollutant of concern, but fireworks emissions may also contribute to higher AQI readings for both PM2.5 and Ozone at times. Active children and adults, especially people with pulmonary or respiratory disease such as asthma, should limit prolonged outdoor activity. Area residents are urged to reduce pollution levels. Air quality forecasts, current air quality, and tips on how you can reduce your emissions can be found at www.airnow.gov. Media contact...Illinois EPA.