INDIANAPOLIS (AP) _ The Indiana Department of Environmental Management warns high ozone levels in southern Indiana could cause breathing and heart problems for certain people Thursday.
 
  The agency is forecasting high ozone levels for the Columbus-Seymour area and the Indiana suburbs of Louisville, Ky.
 
  It says anyone sensitive to poor air quality may be affected when ozone levels are high. Children, the elderly and anyone with heart or lung conditions should reduce or avoid exertion and heavy work outdoors. 
 
  Ground-level ozone is formed when sunlight and hot weather bake vehicle exhaust, factory emissions and gasoline vapors. 
 
  IDEM encourages people to reduce ground-level ozone by conserving energy and reducing automobile and gasoline-powered lawn equipment emissions until 7 p.m.