Los Angeles topped the list, followed by three other California urban areas. Smog affects people's ability to breathe throughout America in small, medium and large metropolitan areas every summer. Ozone levels typically rise during the periods between May and October when high temperatures and increased amount of sunlight combine with the stagnant atmosphere caused by air pollution. Ozone exposure may lead to shortness of breath, chest pain when inhaling deeply, wheezing and coughing. Ozone, can be especially unhealthy for children, people with asthma or other respiratory problems and adults who work or exercise outside.
Ozone also can damage trees and reduce crop yields.
Two Areas Added to Ozone Forecasts North Carolina's ozone forecasting network will expand from four to six metropolitan areas with the start of the ozone season on Monday. Fayetteville and Hickory area residents now will have access to air quality forecasts issued in recent years for the Charlotte, Triad, Triangle and Asheville metropolitan areas. The forecasts, which continue through September, advise residents whether the levels of ozone, the primary pollutant in smog, are likely to be good, moderate, unhealthy for sensitive groups or unhealthy. Walt Disney Internet Group, ABC inc.