AIR POLLUTION
AIR POLLUTANTS
SOURCES OF AIR POLLUTION
Natural Sources: Smoke and dust arising from forest fires or volcanic eruptions. Methane gas arising from decaying organic matter.
Man-made Sources: Exhaust gases from factories, power plants and automobiles.
Carbon monoxide, nitrogen oxides, carbon dioxide, methane and sulphur dioxide are the major pollutants of air.
CARBON MONOXIDE
1. It is produced by the incomplete burning of fossil fuels such as petrol, diesel, etc.
2. It is a poisonous gas, it reduces the capacity of the blood to transport oxygen.
SMOG
1. It is made up of smoke and fog. Smoke is made up of oxides of nitrogen and other pollutants.
2. It causes breathing difficulties such as asthma, cough and wheezing in children.
SULPHUR DIOXIDE
1. It is produced by the combustion of fuels like coal in power plants. Petroleum refineries are a major source of gaseous pollutants like sulphur dioxide and nitrogen dioxide.
2. It can cause respiratory problems including permanent lung damage.
CHLOROFLUOROCARBONS(CFCs)
1. These are used in refrigerators, air conditioners, and aerosol sprays.
2. CFCs damage the ozone layer of the atmosphere.
TINY PARTICLES
1. These particles are produced by industrial processes like steel making and mining.
2. These remain suspended in the air for long periods and reduce visibility.
ACID RAIN
1. Oxides of sulphur and nitrogen react with water vapour present in the atmosphere to form sulphuric acid and nitric acid.
2. When these come down with the rain, it makes the rain acidic.
3. This is called acid rain.
MARBLE CANCER
1. Acid rain has resulted in the corrosion of the marble of the Taj Mahal. The phenomenon is called Marble cancer.
2. Suspended Particulate Matter (SPM) emitted by the Mathura Oil Refinery, has contributed to the yellowing of the marble.
GREENHOUSE GASES
Besides CO2, other gases like methane, nitrous oxide, water vapour also contribute to the greenhouse effect.
1. They are also called Greenhouse gases.
2. An increasing amount of carbon dioxide gas in the atmosphere is responsible for global warming.
3. It has resulted in rising sea levels, reduction in rainfall and proved to be a serious threat to the existence of life on the Earth.
WATER POLLUTION
1. Water pollution is the contamination of water by substances harmful to life.
2. Water Pollutants: Sewage, agricultural chemicals and industrial waste are some of the major contaminants of water.
3. Ganga Action Plan: It is an ambitious plan to save the river, Ganga. It was launched in 1985.