Smog is the most common type of atmospheric pollutant which affects a major portion of the world. The combination of two words namely, smoke and fog results in the formation of the word ‘smog’. There are two types of smogs they are classical smog and photochemical smog.
1. classical smog – This is the typical form of smog found in areas which have a humid climate. It is a mixture of smoke, fog and sulphur dioxide. This smog acts as a reducing agent in atmospheric pollution and hence it is also known as reducing smog.
2. Photochemical smog – This type of smog is prevalent in dry and sunny areas of the world. Automobiles and factories emit smoke which contains hydrocarbons and nitrogen dioxide, these compounds under the action of sunlight become the major component of photochemical smog. This smog contains a high concentration of oxidizing agent hence it is also known as oxidizing smog.