McMullen said recognizing ozone gives people a head start since it takes an hour and a half to two hours for information on pollution levels to become available through the internet or the news media. A gas composed of three atoms of oxygen, ozone occurs naturally in the Earth s atmosphere and creates a shield against the sun s ultraviolet rays. It also forms at ground level when emissions by cars, power plants, refineries, chemical plants and other sources react chemically with sunlight. Unhealthy levels of ground-level ozone typically form in the afternoon during the hot summer months when sunny days with high temperatures and low wind speeds are more common, McMullen said. A reduction in lung function .
Ozone can make it more difficult to breathe deeply and vigorously.
If exercising or working outside, people may notice they are taking more rapid and shallow breaths than normal, a problem for outdoor workers. Exacerbation of asthma . Ozone makes people more sensitive to allergens and when the pollutant reaches high levels, more asthmatics have asthma attacks requiring a doctor s attention or use of additional medication. Also, asthmatics are more severely affected by the reduced lung function and irritation that ozone causes in the respiratory system. Inflammation and damage of lung tissue.