The Louisville Air Pollution Control District has issued the second air quality alert of 2013. Regulators are predicting elevated levels of ozone tomorrow. The Air Quality Index is forecast to be 104, which is unhealthy for sensitive groups. 

These sensitive groups include the elderly, the young, and anyone with heart or lung ailments.

Ozone is formed when pollution from cars and factories cooks under the sun. On bad air days, the Air Pollution Control District recommends Louisville residents avoid idling vehicles, share rides, delay mowing lawns or getting gas and try to combine errands to help improve the air quality.

Erica Peterson is WFPL's News Director.