Ozone is a deadly poisonous gas though it protects the Earth from harmful UV radiations. In other words, when ozone forms at the surface of our planet as a result of pollutants from cars reacting with UV rays, it turns out to be a lethal pollutant itself.
In its pure form or when mixed with other substances, ozone causes many health hazards in humans. Inhalation of low amounts of ozone causes chest pain, coughing, shortness of breath, throat irritation, lung irritation etc. Ozone can also damage forests and crops.