(ii) Describe the major source of air pollution.
Answer. Combustion of coal, petrol and diesel, industrial processes, solid waste disposal, sewage disposal, etc. are the major sources of air pollution because they add oxides of sulphur, oxides of nitrogen, carbon monoxide, hydrocarbons, ammonia, lead, aldehydes, asbestos and helium in the atmosphere.

(iii) Mention major problems associated with urban waste disposal in India.
Answer. Solid waste disposal is a serious problem in most of the Indian cities and towns where it accumulates on the streets, open spaces between houses and wastelands causing serious health hazards, obnoxious smell, harbouring flies and rodents, acting as carrier of diseases like typhoid, diphtheria, diarrhea, malaria and cholera, etc.

It causes frequent nuisance when carelessly handled, spreads by wind and rain water and results in water pollution when dumped into rivers.

(iv) What are the effects of air pollution on human health?
Answer. 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. It causes various diseases related to respiratory, nervous and circulatory systems. Smoky fog over cities called as urban smog is caused by atmospheric pollution. It is very harmful to human health and can also cause acid rain.

Question.3. Answer the following questions in about 150 words.

(i) Describe the nature of water pollution in India.
Answer. Indiscriminate use of water by increasing population and industrial expansion has led to the degradation of the quality of water considerably.

1. Surface water available from rivers, canals, lakes, etc. It contain small quantities of suspended particles, organic and inorganic substance. When concentration of these substance increasing the water become polluted and unfit for use to the extent that even the self-purifying capacity of water is unable to purify it.
2. Human beings pollute the water through industrial, agricultural and cultural activities with industry being the most significant contributor, producing several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc. disposed off in running water or lakes which destroy the bio-system of these waters. Major water polluting industries are leather, pulp and paper, textiles and chemicals.
3. Various types of chemicals used in modern agriculture such as inorganic fertilizers, pesticides and herbicides are other pollution generating components which infiltrate the soil to reach the ground and surface water.
   Cultural activities such as pilgrimage, religious fairs, tourism, etc. cause water pollution in India.
4. Though river pollution is common to all rivers, yet pollution of river Ganga flowing through one of the most populous regions of India is of great concerns.

(ii) Describe the problem of slums in India.
Answer. The urban centres in India are differentiated areas in terms of the socio-economic, politicocultural and other indicators of development, characterised by well-developed urban infrastructures for the high income group and at the other extreme by the slums, “jhuggi jhopari”, which are clusters and colonies of shanty structures.

1. Slums are inhabited by the people forced to migrate from the rural areas to the urban centres in search of livelihood but could not afford proper housing due to high rents and costs of land.
2. These are environmentally incompatible, residential areas of least choice, dilapidated houses, poor hygienic conditions and ventilation, lack basic amenities like drinking water, light and toilet facilities, etc. with serious health and socio-environmental hazards like open defecation, unregulated drainage system and overcrowded narrow street patterns.
3. Most of the slum population works in lowpaid, high risk-prone, unorganized sectors of the urban economy, are undernourished, prone to different types of diseases and illness and cannot afford proper education for their children.
4. Poverty makes them vulnerable to drug abuse, alcoholism, crime, vandalism, escapism, apathy and social exclusion.

(iii) Suggest measures for reduction of land degradation.
Answer. Measures for the reduction of land degradation are as following:

1. The farmers should be given proper training about the use of chemicals and fertilizers.
2. Industrial waste water should be recycled after proper treatment and be used for purpose like irrigation.
3. Plastic and its use should be restricted.
4. Human and household waste can be converted into useful manure.
5. Slum dwellers should be provided with the facility of public toilets.