Air Pollution in Indian Cities

"There is so much pollution in the air now that if it were not one of our lungs, there would be no place to put it all"

-Robert Orden

This famous quote epitomizes mankind's current state of respiration. To some this quote may seem somewhat exaggerated, but it is true nonetheless. The air we breathe directly gets into contact with the most sensitive organs like respiratory tract and lungs of the human body. Air pollution is the most hazardous environmental factor from the public point of view, because every individual breathes approximately 22000 times a day, inhaling about 15 to 20 kg of air daily. The World Health Organization (WHO) defines air pollution as "Limited to situations in which the outer ambient atmosphere contains materials in concentrations which are harmful to man and his environment". According to a survey conducted by the WHO, around 2.4 Million premature deaths are happening mainly due to air pollution. Air pollution has become a life-threatening factor in the world. The air pollution is mainly caused by urbanization, which leads to a far larger amount of carbon dioxide to be released into the atmosphere.

Air pollution in urban areas is mainly caused by 4 factors:

1. Increasing traffic

2. Expanding cities

3. Large scale economic development

4. Rapid industrialization

Air pollution is also caused by some of the natural activities like lightning discharges, biological decaying of vegetable matter, photochemical oxidation of organic matter, sudden eruption of volcanoes, etc. Increases in population, deforestation, burning of fossil fuels, etc. are human-caused.

Most Indian cities are polluted majorly by industrialization. Their activities release pollutants like volatile organic compounds, compounds containing sulphur and nitrogen, halogens, chlorofluorocarbons, lead, suspended particulate matter (SPM), carbon dioxide and carbon monoxide. These pollutants when present in atmosphere undergo chemical reaction to become smog and acid rains.

Smog is the combination of various gases, fine particles of water vapours and dust, which assumes the form of fog when it reacts with heat and sunlight. This smog is formed when fuel is burnt in large quantities. Acid rain is formed when nitrogen oxide and sulphur oxide from the burning of fossil fuels such as petrol, diesel and coal react with atmosphere moisture or hydroxyl radical. This acid rain causes ham to plants, buildings sculptures of marble, slate, limestone etc. The best example is the Thaj in Agra. Other major effects of air pollution by urbanization include ozone layer depletion caused by usage of chlorofluorocarbons in the air conditioner coolants and as propellant in aerosol cans.

Air pollution causes deleterious health effects like skin disease, cancer, irritation of respiratory systems, long skin disease, asthma, etc. The Air (Prevention and control of pollution) Act, 1981 of Government of India came into force on May 16^th 1981. This act is applicable throughout India and provides integrated approach for tackling air pollution. Air pollution can be minimized at the source by adopting measures like raw material substitution, modifying the process and altering the particular equipment of component for the removal of pollutants at the source. Currently, among major Indian cities, Kolkata has the worst air pollution record followed by Mumbai.

Clean air is a vital requirement for the continued existence of mankind. The study of air quality at this alarming level of air pollution has become very necessary. People must be made more aware of the importance of air for life and the level to which air has already been polluted. A solution for air pollution requires tracking it in a systematic way. Unless people make consumer decisions to keep air clean, such as by purchasing low-emission automobiles, the goal can not be forced into fruition. Hence, the common man plays an important role in avoiding air pollution.