Smog is the form of pollutant that consists of nitrogen oxides, sulphur oxides, ozone, smoke and other particulates . During summer smog gets associated with the photo-chemical compounds known as secondary pollutant (which are formed of primary pollutants) which undergo chemical reactions in the atmosphere.
Compound like nitrogen oxides , volatile organic compounds go through a series of chemical reactions with sunlight, moisture, and other compounds to produce ground level ozone that further turns into smog
