Ozone Formation

Ozone formation occurs when pollutants called nitrogen oxides (NOx) and volatile organic compounds (VOCs), released from vehicles, factories, and other sources, react in the presence of sunlight. These chemical reactions produce ozone, a molecule composed of three oxygen atoms. While ozone high in the atmosphere protects us from ultraviolet radiation, at ground level it can cause health problems and environmental damage. The process is more active on sunny days, especially in urban areas with high emissions. Managing emissions of NOx and VOCs is essential to controlling ground-level ozone pollution.