Ozone is a gas with a pungent odor and is a main component of smog. Upper atmospheric ozone acts to shield the earth from the harmful effects of sunlight, and should not be confused with the more dangerous ground-level ozone which is considered a form of air pollution. Electrical sources such as x-ray or ultraviolet generators, arc welding equipment, and mercury vapor lights also produce ozone. Ozone is used as an oxidizing agent in the chemical industry, as a disinfectant for air and water, for bleaching textiles, oils, waxes, and paper pulp, for aging liquor and wood, and in treating industrial waste. Ozone levels in some urban areas typically rise from May through September.
Ozone is a respiratory irritant.
Symptoms include shortness of breath, chest pain when inhaling deeply, wheezing, and coughing. There is evidence that the lung function changes experienced at somewhat higher ozone levels may persist for several days after the exposure. Repeated exposure to ozone can make people more susceptible to respiratory infection and lung inflammation, and can aggravate preexisting respiratory diseases. Recently, attention has begun to focus on the effects of long-term, repeated exposures to high levels of ozone. A. Children are most at risk from exposure to ozone because they are active outside, playing and exercising during the summertime when ozone levels are at their highest.