What is pollution? What are its types? Write a short note on the causes of different types of pollution.
Pollution is an undesirable change in the environment. Most of the abiotic components like water, air, soil are polluted day-by-day thereby polluting the environment.
Water pollution:
Water is an essential natural resource. Water exists in different resources like ponds, lakes, rivers, seas, oceans etc. Pollution of water resources shows effects on the environment as well as the living organisms. Pollution of water makes it undesirable for usage. Different causes for water polluion are dumping of untreated sewage, dumping of toxic industrial wastes, dumping of agricultural wastes, oil spills caused by ships travelling in ocean etc.
Air pollution:
Air is an abiotic factor which is essential for all the living organisms in the process of respiration. Oxygen in air is essential for combustion. Nitrogen in air is utilised by plants with help of some bacteria. Carbon dioxide is essential for the plants which synthesise the food for them and other living organisms. Air is polluted by different factors like smoke released by automobiles and industries, dust released by industries and mining wells, different chemicals ( CFCs, freons) used in refigerators and aircondiioners etc. Gases released by automobiles and industries are poisonous sometimes and may include SO2, NO2, Methane, Carbon monoxide, Carbon dioxide, other green house gases etc. Fuels used in rockets also release lot of pollutants into the atmosphere. Air is also polluted by pollen from some plants. Some microbes which cause diseases also exist in air.
Soil pollution:
Soil is the top most cover on the surface of the earth. It is polluted by dumps caused by domestic wastes, industrial wastes etc. Some toxic chemicals from the industrial wastes percolate into the soil and cause ill- effects. Plastic is another major pollutant of the soil. It is a non-biodegradable resource that gets burried in the soil and takes several years for decomposition. Usage of chemical fertilisers and pesticides also have an effect on the soil during a course of time.
Noise pollution:
Noise is the unwanted unbearable sound in the environment. Noise pollution is also harmful for the living organisms. It shows adverse effects on them. Airplanes, helicopters, automobiles cause noise pollution. Constructions of buildings also cause noise pollution. Industries also cause noise pollution.
Thermal pollution:
This is an increase in the temperature of the environment due to certain natural and man-made causes. Release of carbon dioxide by burning fossil fuels like coal, petroleum is also a cause for thermal pollution. Increase in temperature beyond certain level is called as global warming. Global warming leads to melting up of polar ice-caps which in turn results in submerging of low-lying areas.