INDIANAPOLIS — Sunday, Sept. 18 has been declared an “Air Quality Action Day” in Indiana, as announced by the state’s department of environmental management.

IDEM released a statement Saturday saying that starting at midnight and lasting until 11:59 p.m. Sunday, anyone sensitive to changes in air quality may be affected. Due to potentially high ozone levels, IDEM is advising that children and the elderly, as well as those with heart or lung conditions, should reduce or avoid heavy exertion or work outdoors.

“Ground-level ozone is formed when sunlight and hot weather combine with vehicle exhaust, factory emissions, and gasoline vapors,” IDEM said in the release. “Ozone in the upper atmosphere blocks ultraviolet radiation, but ozone near the ground is a lung irritant that can cause coughing and breathing difficulties for sensitive populations. “

IDEM said they examine weather patterns and current ozone readings to make daily air quality forecasts. Air Quality Action Days usually will occur when conditions like light winds, hot and dry air, stagnant conditions, and lower atmospheric inversions trap pollutants close to the ground, IDEM said.

To learn more about ozone or to sign up for air quality alerts, visit