Sources, Effects Ant Control of Air Pollution
The World Health Organization has defined air pollution as, “the presence of materials in the air in such concentration which are harmful to man and his environment.” Air pollution is the addition of foreign particles, gases and other pollutants into the air. They produce adverse effect on human beings, animals, vegetation, buildings, etc.
Some of the important sources of air pollution are burning of natural gas, petroleum, coal and wood in industries, thermal plants, automobiles, aircrafts, railways, agricultural burning, kitchens, etc. Chemical industries like pesticides and fertilizers are other important sources of contaminating the air. Processing industries like wheat flour mills, stone crushing, welding, cotton textiles and gem grinding also contribute to air pollution.
Natural air pollutants include poisonous gas, gases released during volcanic eruption and mixture of harmful chemicals during storms. The major cause of pollution in the urban areas is the release of air pollutants due to burning of petroleum in automobiles. Concentration of industries in one area is another major cause of air pollution.
The air pollutants have adverse effect on human beings, animals, vegetation and even buildings. The climate of the Earth is changing due to it. Dust and smoke particles in air cause irritation of the respiratory tract and leads to asthma, bronchitis and lung diseases. Incomplete combustion of carbon fuels in several industries, motor vehicles, kitchens, etc. releases carbon monoxide gas. When this gas combines with certain substances in blood, it harms the oxygen carrying capacity of blood making it fatal.
When petroleum and coal are burnt in industries, thermal plants and motor vehicles, a poisonous gas called sulphur dioxide is produced. When it mixes with the rainwater, it forms sulfurous acid resulting into acid rain. Such rain leads to staining and corrosion of buildings, painted surfaces, sculptures, fabrics, paper, leather, etc.
Due to excessive combustion activity, the quantity of carbon dioxide in air has been steadily rising. As carbon dioxide accumulates in the atmosphere it absorbs more and more reflected infrared radiation. This causes an increase in the atmospheric temperature. Melting polar ice caps and glaciers could cause sea levels to rise, flooding most of the major human settlements.
By taking certain measures, air pollution can be controlled. Industrial estates should be established at a distance from residential areas. Very tall chimneys must be used by industries and factories to reduce the air pollution in the surrounding areas. Poisonous gases must be removed by passing them through water tower scrubber or spray collector. High temperature furnaces must be used for decrease in ash production. There should be development and employment of non-combustive sources of energy such as solar power, tidal power, wind power, etc. Attempt should be made to manufacture automobiles that are completely pollution free. Automobiles should be fitted with exhaust emission controls. Industrial plants and refineries should be fitted with equipment for removal and recycling of wastes.