Though it acts as a protective layer high above the earth, ozone can be harmful to breathe. It is the prime ingredient of smog, in our cities. Ground-level ozone forms readily in the atmosphere in hot weather.
Many urban areas tend to have high ozone levels.
However, areas downwind of urban settings are also subject to high ozone exposure, as winds carry VOCs and NOx from their original sources. Health and environmental effects of ground-level ozone When inhaled, ozone can damage the lungs. Relatively low amounts of ozone can cause chest pain, coughing, nausea, throat irritation, and congestion. It may also worsen bronchitis, heart disease, emphysema, and asthma. Healthy people as well as those with respiratory problems, experience breathing problems when exposed to ozone.