The resulting symptoms may include coughing, throat irritation and breathing difficulty. Inhaling ozone can affect lung function and worsen asthma attacks. Ozone may increase the susceptibility of the lungs to infections, allergens and other air pollutants. Medical studies have shown that ozone damages lung tissue and that unhealthful effects may continue for days after exposure has ended. Air quality in these areas exceeds the federal health standard for ozone on numerous days each summer.
Ozone is a major element of urban smog.
Ozone can lower resistance to colds and pneumonia, damage lung tissue, intensify heart and lung disease, and cause coughing and throat irritation. Even healthy adults who perform heavy physical exercise or manual labor outdoors experience the unhealthful effects of ozone. The primary sources of VOCs and oxides of nitrogen are automobile and industrial emissions. Other sources of VOCs include dry cleaners and consumer products such as paints, insecticides and cleaners. Ozone concentrations can reach unhealthful levels when the weather is hot and sunny with little or no wind.