Ozone (O3) is a secondary pollutant that forms when nitrogen oxides and volatile organic compounds react in the presence of sunlight. Ozone is a molecule of oxygen that consists of three atoms rather than the usual two, giving it a distinct chemical structure and unique properties. It is a highly reactive molecule that can oxidize and damage organic materials, including human tissues and plant life. Ozone is a significant component of smog and is a major contributor to air pollution in urban areas. Exposure to high levels of ozone can cause a range of respiratory problems, including coughing, wheezing, and shortness of breath. Additionally, long-term exposure to elevated ozone levels has been linked to lung damage and decreased lung function. Ozone is regulated by government agencies, and efforts are ongoing to reduce its levels and limit its impact on human health and the environment.