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After reading this essay you will learn about how environment is exploited in useful and harmful ways.
An individual cannot live in isolation in nature. For its survival and perpetuation of its race, an individual often associates with other individuals of its own kind. All the similar individuals of a given locality, which form single sexually interbreeding groups are called population.
A species is a group of similar individuals that live together and interbreed to produce off-spring. Thus, all rice plants, all human beings, all tigers, etc., each represents a species.
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Many groups of population belonging to different species form the next higher level of organisation, called biotic community. For example, all plants and animals inhabiting a crop field constitute a biotic community. The biotic communities found in any geographical region have to interact with physical environment of the place.
Both biotic or living (plants, animals and microbes) and abiotic or non-living (soil, water, light, air, heat, etc.) together constitute next higher level of organisation called ecosystem. Ecosystem is an ecological unit. A variety of habitats in a place may form different ecosystems. Thus, an ecosystem may be as small as a pond or as large as a forest.
The sum of all ecosystems of all the geographical regions of the earth forms the next higher level of organisation, called biosphere. Biosphere is the largest ecological organisation and in fact is a huge ecosystem that includes biological world (living matter) and non-living components in the form of lithosphere (earth), hydrosphere (water) and atmosphere (air).
Until about 50,000 years ago, man was as wild as any other mammal. He was an integral part of the biological community in which he lived. But the boon of thinking by the highly developed human brain has given certain unique advantages to man.
As the man’s knowledge grew, the environment was exploited more and more. Such exploitation does not persist at micro-level but exists at macro-level, i.e., on large scale and often assumes a global level. Such exploitation can be useful or harmful.
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Useful Exploitation:
Man is at the top of ecological pyramid. With the advancement of technology, man ventures to live in quite unfavourable places in the world. He can cure diseases by drugs discovered in certain distant places; the use of computer can control the direction of movement of satellite to land on the moon or to intercept the destructive missiles. Many such examples can be cited about the useful exploitation of environment.
Harmful Exploitation:
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With the rapid increase in population of human beings or live-stocks, the requirement for land for cultivation, grazing has also been increasing along-with. This has led to reclamation of wastelands and forests and has resulted in large scale deforestation.
It is known that forests affect rainfall through recycling moisture back into atmosphere through transpiration which again falls as rain. Due to deforestation, this natural water cycle is broken and water is lost through rapid run-off.
Forests have been destroyed for obtaining fuel, timber, fodder, industrial raw materials and medicines, etc. Numerous forests have been cleared for mining. In addition, forests fire destroys the standing trees, consumes the seeds, burns the rich humus of the soil and poses grave danger to animal and human life.
The use of insecticides, pesticides and herbicides to control insects, pests and weeds is also potential health hazard. Majority of synthetic insecticides fall into two groups—chlorinated hydrocarbon and organophosphates. The chlorinated hydrocarbon includes DDT, dieldrin, endrin, aldrin, chloralane, lindane, etc. These compounds are toxic and water soluble. They are soluble in fats and tend to accumulate in the fatty tissues of animals. They are poisons and affect a wide variety of animals.
The organo-phosphates include parathion, malathion, phosdrin and others. These are also poisons and cause increased activity of nervous system and the victim dies. Though, the widespread use of these toxic chemicals increases agricultural yield, but their small amount in the grains has ill effect on man’s health.
Man has exploited various natural resources for his comfort, welfare and survival. The use of electricity, trains, aeroplanes, cars and establishment of industries has increased carbon dioxide in the air and has affected the ozone layer. It is the ozone layer which protects all the living beings from the harmful ultraviolet rays of the sun.
When industrial waste is dumped in the environment, it results in pollution. Pollution may be defined as an undesirable and excessive addition of substances to water, air and land which adversely alters the natural quality of the environment.
A pollutant is a constituent in the wrong amount at the wrong place at the wrong time. For example, nitrogen and phosphorus are essential nutrients for living organisms and are extensively used in agriculture to increase crop yields, but they also cause pollution in lakes, rivers when found in excess.
Pollutants of industrial wastes have the following two main effects:
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(1) Water gets polluted by disposal of sewage and industrial effluents. The industrial wastes contain heat, poisonous materials like acid, alkalies, salt, phenol, chlorines, ammonia, lead, zinc and other heavy metals. The industries which generally pollute water are—Paper mill, Textile, Sugar, Distilleries, Leather and Rubber industries. Most of the rivers of India, specially Ganga, Krishna, Yamuna, Kulu and the lakes of the Kashmir valley are seriously polluted. The industrial effluents kill the animal and plant life and make water unsafe for drinking.
(2) Many industries release smoke in the air, smoke contains SO2, CO and NO, etc. These gases are injurious to health. The sulphur dioxide (SO2) damages plants and forms sulphuric acid by reacting with water and results in acid rain. The smokes check the growth of vegetation. A great loss of human life occurred during 1984 by the leakage of toxic gas from an insecticide industry in Bhopal.
Recently, in Gulf war, the gases and smokes produced by the several lakh tons of bombs dropped, burning of oil refineries and by the release of crude oil to the Gulf water will certainly cause serious environmental problems not only to the Gulf region but also to the world at large.
Once, the balance of nature is disturbed, it becomes very difficult rather impossible to restore it.
From the above, it becomes clear that environment can be exploited in useful and harmful ways. The best approach is to maximise the positive (beneficial) and to remove all the negative (adverse) effects. Often this is not easy. When a step is taken to have short-term gain, this can lead to incurable damage to environment.
At this stage, the role of environmental protection groups such as Chipko Movement in Uttarakhand (formerly U.P.) and Citizen’s Forum in Kerala for silent valley, Aranyak in Assam, Save Guwahati Build Guwahati etc. becomes very important.