Traffic moves down Interstate 24 as haze covers the Chattanooga area in this file photo. Air pollution control officials say that the hot, dry summer contributes to unhealthy ozone conditions. A code orange health watch has been declared for ozone in Chattanooga tomorrow, June 10, with an air quality index of 105.

An air pollution Code Orange Health Watch has been declared for ozone in Chattanooga on Wednesday.

The air quality Index is predicted to be 101 which is unhealthy for sensitive groups. The designation means there could be adverse health effects for up to 50 percent of the population, according to Amber Boles, spokeswoman with the Chattanooga-Hamilton County Air Pollution Control Bureau.

"Active children and adults, and people with lung disease, such as asthma, should limit prolonged outdoor exertion," Boles said in a prepared statement.

People at risk include children and adults who are active outdoors, people with asthma or other respiratory conditions and people with unusual susceptibility to air pollution.

People can help keep ozone levels lower by driving less, postponing gasoline-powered lawn care, refueling after 6 p.m. and reducing their electric usage.