Air Pollution

The World Health Organization defines air pollution or atmospheric pollution as the presence of materials in the air in such concentration which are harmful to man and his environment. Air pollution is one of the most hazardous and common class of environmental pollution. It has an unfavorable effect on all living things. It brings about untimely fatality for flora and fauna. In recent years, the problem of air pollution has become very severe. It rises due to the hunger for riches and ignorance of human. A sign of development seems to be the increasing number of vehicles on Indian roads. But, the key cause of air pollution in the urban India is automobiles which inefficiently burn petroleum and release 80% of air pollutants. On the other hand, deforestation is on an unprecedented scale which has created a greater pressure on the quality of air. The large scale production by industrialization has also resulted in air pollution. Concentration of industries in one area is another major cause of it. One should remember that air pollutants even in small concentration are extremely destructive to life and assets. The combustion of fossil fuels like natural gas, petroleum and coal as well as wood in industries or automobiles or aircrafts or railways or thermal power plants, agricultural burning and domestic uses etc has caused the air pollution. Metallurgical processing creates mineral dust and fumes containing poisonous or toxic substances like fluorides, sulphides, lead, chromium, nickel, beryllium, arsenic, vanadium, cadmium, zinc, mercury etc. As a result, generations to come are likely to suffer from a number of incurable diseases. Its very extreme can even threaten the existence of human races. Chemical industries like asbestos, cosmetics, welding etc, cotton and textiles industry, wheat flour mills, stone crushing and gem grinding industry add to air pollution. It is estimated that 52% of air pollution is caused by carbon dioxide, 18% by sulphur dioxide, 12% by hydrocarbons and 10% by particulates consisting of soot, fly ash, dusts of various types, fur, hair, spores and pollen grains etc, 6% by nitrogen dioxides and 2% by the remaining. Some natural things and process may also cause air pollution to some extent. The natural air pollutants include pollens, spores, marsh gases, volcanic gases and synthesis of harmful chemicals by electric storms, lightning and solar flares.

Generally, air pollutants not only impair oxygen transport that results in giddiness, asphyxia, decreased vision and cardiovascular malfunction but also cause the damages of building, sculptures and painted surfaces etc. A study conducted by the World Bank in 1995 revealed that 40,000 Indians die prematurely due to the polluted air in cities. Yet another study made by the Environmental Protection Agency shows that every year nearly 40,000 children in India are affected by respiratory disorders caused by the growth of carbon dioxide in the atmosphere. Modern environmental biologists feel that the increase in air pollution may cause the reduction in the amount of sunlight energy reaching to the earth’s surface which lowers solar radiation at the earth’s surface and produce a cooling effect on world climates. It could ultimately prompt another ice age. The other scientists believe that the air pollution causes what is called the Green House Effect. It results in the heating of the earth’s surface. It is fueling global warming which has serious consequence for life on this planet. Recently certain ecologists have tried to correlate air pollution with serious and prolonged droughts, heavier rains and floods and more serious hurricanes and tornadoes. The reported threat to the Taj Mahal of Agra from nearby refinery of Maharastra is due to the presence of sulfur dioxides in air. If the air continues to be polluted in this way in urban India, humans will face greater and greater health hazards. Air will not remain breathable and health will suffer.

Chronic diseases like bronchitis, lung cancer and emphysema are caused by air pollution. It is estimated that mortality from lung cancer could be lowered 25% by a 50% reduction in air pollution. Due to air pollution the incidence of respiratory disease in Delhi is about 12 times the national average. Air pollutants also cause a number of other diseases including eye irritation, dizziness, headaches, nasal irritation, coughing and shortness of breath, sore throat, chest pains, increased cold and allergies etc. They also produce offensive odors and give general discomfort anxiety or suffering to people. There are several abiotic and biotic factors that can affect the response of plants to an air pollutant exposure dose. It causes soiling of clothing and curtains.

As air pollution is not visible to the naked eye, it cannot be handled or removed by individual efforts. It requires awareness among all the people to check the air pollution. At first, there should be balanced and planned industrializations in India. Urbanization should be well planned. Pollutants should be destroyed by the use of suitable scientific technique like incineration. A comprehensive programme of tree plantation should be taken in hand. Deforestation should be prohibited. Besides, an intensive research is essential to solve it. Certain other protective measures should also be adopted for effective control of this menace. There should be sustained efforts to find alternatives like solar powered vehicles and appliances to reduce our dependence upon oil engines to run vehicles and generator sets.

To measure and control the magnitude of air pollution in various industrial hubs of India, National Environmental Engineering Research Institute (NEERI) has set Air Monitoring Stations in Mumbai, Kolkata, Delhi, Madras, Hyderabad, Kanpur, Jaipur, Ahmedabad and Nagpur. Delhi is getting special attention on account of its high pollution level. The WHO has classified this city among the ten most polluted cities in the worked. In India, air pollution control legislation envisages the formation of Air Pollution Boards at the central and state levels with powers to issue and revoke licenses to polluting industries, enforce emission standards and frame rules and regulations for the control of air pollution. However, there is a need of legislation to deal with fumes of Petrochemical Units, ash, carbon particles and unpalatable smell and even noises from industrial units. In order to collect information about the nature, sources and extent of air pollution, a national Air Quality Monitoring Programme is conducted by the Central Pollution Control Board (CPCB) with the objectives of identification of areas in need of restoration of air quality and their prioritization, identification of nature and extent of pollution control need and assessment of the effectiveness of pollution control programme.. As vehicular emissions are major pollutants of ambient air quality, vehicular pollution is sought to be controlled.

Government of India’s new auto fuel Policy has laid out a road map to cut down vehicular pollution in urban India. The goal of this policy is to reduce sulphur and aromatics contents in petrol and diesel to 50ppm and 35% respectively. The Bharat stage II (equivalent to Euro II norms) will be applicable to all the automobiles throughout the country from April 1, 2005. Cities like Delhi, Mumbai, Chennai, Bangalore, Hyderabad, Ahmedabad, Pune, Surat and Kanpur. Agra will have to meet EuroII emission norms from April 1, 2005 and Euro IV emission norm from April 1 2020.

Air pollution may be controlled and reduced if industrial plants should be advised to use high chimneys for escape of smokes fumes or heated air. If the pollutants are part of the fuel, we can consider using fuels with lower pollutant content, removing the pollutant from the fuel and during the combustion process. The use of Compressed Natural Gas (CNG) has reduced air pollution to a great extent because CNG burns more efficiently than petrol or diesel. It is cheaper as well as very little of it is left unburnt. It, also, cannot be siphoned off by thieves or adulterated like petrol or diesel. Public awareness regarding air pollution, potential of sewage and many other solid wastes will certainly help in reducing air pollution in town and cities. It should be made mandatory for municipalities to carry out the proper treatment of sewage and other wastes. Many plant species have been evaluated for their scavenging potential against air pollutants. It has been suggested that the efforts should be made for green belt development since it serves as a sink for air pollutants. To remove the particulate matter in the air, it should be filtered before releasing it into the air. Plantation should be done on a large scale. Trees use carbon dioxide and release oxygen and depollute the air. Control equipments likes gravity settling tanks or porous filters and electrostatic precipitators should be installed in factories to minimize the air pollution.