NCERT Book Class 12 Geography Geographical Perspective on Selected Issues and Problems

GEOGRAPHICAL PERSPECTIVE ON SELECTED ISSUES AND PROBLEMS

Environmental Pollution

Environmental pollution results from ‘the release of substances and energy from waste products of human activities. There are many types of pollution. They are classified on the basis of medium through which pollutants are transported and diffused. Pollution can be classified into (i) air pollution, (ii) water pollution, (iii) land pollution and (iv) noise pollution.

Water Pollution

Indiscriminate use of water by increasing population and industrial expansion has led degradation of the quality of water considerably. Surface water available from rivers, canals, lakes, etc. is never pure. It contains small quantities of suspended particles, organic and inorganic substances. When concentration of these substances increases, the water becomes polluted, and hence becomes unfit for use. In such a situation, the self-purifying capacity of water is unable to purify the water. Though water pollutants are also created from natural sources (erosion, landslides, decay and decomposition of plants and animals, etc.) pollutants from human sources are the real causes of concern. Human beings pollute the water through industrial, agricultural and cultural activities. Among these activities, industry is the most significant contributor.

Industries produce several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc. Most of the industrial wastes are disposed off in running water or lakes. Consequently, poisonous elements reach the reservoirs, rivers and other water bodies, which destroy the bio-system of these waters. Major water polluting industries are leather, pulp and paper, textiles and chemicals.

Various types of chemicals used in modern agriculture such as inorganic fertilisers, pesticides and herbicides are also pollution generating components. These chemicals are washed down to rivers, lakes and tanks. These chemicals also infiltrate the soil to reach the ground water. Fertiliser induces an increase in the nitrate content of surface waters. Cultural activities such as pilgrimage, religious fairs, tourism, etc. also cause water pollution. In India, almost all surface water sources are contaminated and unfit for human consumption.

Water pollution is a source of various water borne diseases. The diseases commonly caused due to contaminated water are diarrhoea, intestinal worms, hepatitis, etc. World Health Organisation shows that about onefourth of the communicable diseases in India are water-borne.

Air Pollution

Air pollution is taken as addition of contaminants like dust, fumes, gas, fog, odour, smoke or vapour to the air in substantial proportion and duration that may be harmful to flora and fauna and to property.

Noise Pollution

Noise pollution refers to the state of unbearable and uncomfortable to human beings which is caused by noise from different sources. This matter has become a serious concern only in recent years due to a variety of technological innovations.

The main sources of noise pollution are various factories, mechanised construction and demolition works, automobiles and aircrafts, etc. There may be added periodical but polluting noise from sirens, loudspeakers used in various festivals, programmes associated with community activities. The level of steady noise is measured by sound level expressed in terms of decibels (dB).

EXERCISES

1. Choose the right answers of the following from the given options.

    (i) Which one of the following river is highly polluted?

         (a) Brahmaputra                               (c) Yamuna

         (b) Satluj                                         (d) Godavari

    (ii) Which one of the following deseases is caused by water pollution?

         (a) Conjunctivitis                               (c) Respiratory infections

         (b) Diarrhorea                                   (d) Bronchitis

    (iii) Which one of the following is the cause of acid rain?

         (a) Water pollution                            (c) Noise pollution

         (b) Land pollution                              (d) Air pollution 

    (iv) Push and pull factors are responsible for–

         (a) Migration                                    (c) Slums

         (b) Land degradation                        (d) Air pollution

2. Answer the following questions in about 30 words.

    (i) What is the difference between pollution and pollutants?

    (ii) Describe the major source of air pollution.

    (iii) Mention major problems associated with urban waste disposal in India.

    (iv) What are the effects of air pollution on human health.

3. Answer the following questions in about 150 words.

    (i) Describe the nature of water pollution in India.

    (ii) Describe the problem of slums in India.

    (iii) Suggest measures for reduction of land degradation.

Please refer to attached file for NCERT Class 12 Geography Geographical Perspective on Selected Issues and Problems