Times Staff Report

INDIANAPOLIS | The state is asking region residents to curtail driving and other smog-producing activities today.

Hot weather and sparse winds were expected, prompting the state to declare an ozone Air Quality Action Day for Lake, LaPorte and Porter counties.

Smog, or ozone, accumulates when pollution -- from factories, vehicle tailpipes, lawn mowers and other sources -- bakes under hot, sunny, windless weather. This ground-level ozone can irritate respiratory systems, causing coughing and difficulty breathing.

The Indiana Department of Environmental Management recommends children, the elderly and those with heart conditions or asthma and other lung ailments avoid intense exercise and heavy work outdoors until smog levels recede late this evening.

IDEM suggests residents avoid driving by walking, biking, car pooling or taking public transportation.