Smog Is a Form of Air Pollution.

Smog is a form of air pollution. It is made up of a combination of smoke and fog. In the old days smog was mainly caused due to the burning of coal. The mixture of smoke and sulfur dioxide is what resulted in the formation of smog.However, the modern age smog does not originate from coal. Its main source is vehicular and industrials exhaust. The emissions are acted on by sunlight and a secondary pollutant is formed. The formed secondary pollutant then combines with the primary pollutant to form photochemical smog.

Photochemical smog

This type of smog forms when sunlight hits several types of pollutants that are in the air. The resulting combination of chemicals is inimical and is very dangerous. Photochemical smog is formed when there is a chemical reaction between sunlight, nitrogen oxides (NOx) and atmospheric volatile organic compounds (VOCs) .This leads to the formation of airborne particles that are known as particulate matter and a type of ozone that is referred to as ground-level ozone. It is worth noting that this type of smog was first described in the 1950s.

The release of Nitrogen Oxide is b the action of Nitrogen and Oxygen. When the two react together under the influence of elevated temperatures such as the ones that are found in the exhaust of a car engines that run under the action of fossil fuels. Other types of engines that produce this type of a reaction are the engines of trucks, industrial manufacturing plants and coal power plants.VOCs however are produced from man made sources. Such sources include petrol, pesticides, paints, solvent and other bionic sources such as citrus and pine plant emissions.

Constituents of Smog

The noxious smog mixture is made up of the following chemicals.

1. Tropospheric ozone

2. Oxides of nitrogen such as nitrogen dioxide

3. Volatile organic Compounds (VOCs)

4. Aldehydes (RCHO)

5. Peroxyacyl nitrates (PAN)

The constituent chemicals of ozone listed above are very highly reactive and possess oxidizing potential. This makes photochemical smog a modern day industrial problem. It is a fact that photochemical smog is present in almost all cities of the world. Its concentration is what varies. It is more common in cities having warm and sunny climatic conditions. The effects is even more in cities with a high vehicular traffic density. Its ability to be dispersed by wind makes it even worse as it can easily affect highly populated areas.

Effects on health