Write an essay on solid waste management ?

Solid waste, often called the third pollution after air and water pollution, as that material which arises from various human activities and which is normally discarded as useless or unwanted. It consists of the highly
heterogeneous mass of discarded materials from the urban community as well as the more homogeneous accumulation of agricultural, industrial and mining wastes.

Solid wastes may be classified based partly on content and partly on value. A typical classification is as follows :

(a) Garbage : Refers to non-putrescible solid waste constituents produced during the preparation or storage of meat, fruit, vegetables, etc. These wastes have a moisture content of about 70% .

(b) Rubbish: Refers to non-putrescible solid waste constituents either
combustible or non-combustible. Combustible waste would include paper,
wood, scrap, rubber, leather etc. Non-combustible wastes are metals, glass , ceramics etc. These wastes contain a moisture content of about 25% and the heating value of the waste is around 15 x 106 J/kg.

(c) Pathological Wastes: Dead animals, human waste, etc. The moisture content is 85% and there are 5% non-combustible solids.

(d) Industrial wastes: Chemicals, paints, sand, fly ash etc.

(e) Agricultural wastes:  Farm animal manure, crop residues, etc.

In India authentic information regarding the composition of the urban wastes is not generally available as regular analysis of the refuse is not carried out by the municipalities. In fact, refuse is very heterogeneous in composition and the geographical, temporal and seasonal variations in its composition make it difficult to define a “typical refuse”. The solid refuse generated in urban areas contains articles of various sizes and types and consists of dust, vegetable leaves, waste paper, large paper-board cartons, glass bottles, worn out tyres, carcasses of animals and night soil.

Potential Methods of Disposal

In recent years new and better methods for solid waste management have been suggested and / or developed. Some of the ideas are discussed in this section.

(a) Utilization: Many solid wastes generated by industry can be utilized directly. Fly and bottom ash from power plants can be used commercially, largely as cement substitute. New uses are being developed for fly ash, e.g.,. to make bricks, do dewater industrial wastewater sludge, as a land cover etc. India produces about 6 x 10 tones of bagasse from sugar cane annually. This bagasse can be utilized for the manufacture of paper pulp which can displace hardwood pulp of similar quality and cost. There are some novel uses of sugar cane bagasse. One sugar cane company in South Africa has integrated its operation with the production of eggs and dairy products.

(b) Recovery and Recycling : Solid wastes contain significant amounts of valuable materials like steel, aluminum, copper and other metals which, if they are recovered and reused, would reduce the volume of the wastes to be collected and at the same time would yield significant salvage and resale income. In addition, better reclamation techniques will help to save valuable natural resources and turn wastes, which could be dangerous, into useful products. Some important solid wastes that have been successfully reclaimed  are paper, glass, metals and plastics.

Write short note on Thermal pollution.

Thermal Pollution

Radioactivity is not the only waste that nuclear power plants produce. There is another unseen Waste. For cooling purposes nuclear reactors, thermal power station and various industries use large quantities of water. Many times it is easier to take water from the source of lower temperature and let off the hot water into river causing rise in temperature.

Effect of thermal pollution

Change in temperature has a disastrous effect on aquatic plants and animals. It is estimated that a rise of 3.6 C in the earth temperature would make ice caps to melt in the Antarctic and Arctics. As a result of melting and expansion of water, the level of oceans would go up to 100 meter. Scientists believe that this condition may come in 108 years at the present rate of expansion. Cooling brought by increased dust particles would bring an ice age. This requires only a fall of 4°C in temperature.

Control of thermal pollution

For controlling the thermal pollution factories and power houses should make their cooling towers and spray ponds. This way the water can be used• again and again and the thermal pollution can be eliminated.

Write an essay on Soil Pollution ?

Soil constitutes the upper crust of the earth which support land plants and animals. Like air and water, soil also gets polluted. Soil pollution can be defined ‘the addition of substances to the soil, which adversely affect physical, chemical and biological properties of soil and reduces its productivity. The process of soil formation is very slow, therefore the soil may be considered as non-renewable resource. This makes the problem of soil pollution more acute.

Soil pollution is an extremely complicated process. It may occur directly by dumping, and disposal of wastes, application of agro-chemicals or the indirect result of air pollution such; as acid rains. The main soil pollutants are : (i) industrial wastes (ii) pesticides (iii) fertilizers and manures (iv) discarded wastes (v) radioactive (vi) other pollutants.

(i) Industrial wastes : Both solid and liquid wastes of industries are dumped over the soil. The wastes contain a number of toxic chemicals such as mercury, lead, copper, zinc, cadmium, cyanides, thiocynates, chromates, acids, alkalies, organic substances etc. Some toxic chemicals reach by mining operations also.

(ii) Pesticides:  Now-a-days a number of chemicals are used to kill insects (insecticides), fungi (fungicides), algal bloom (algacides), rodents
(rodenticides), weeds (weedicides or herbicides) in order to improve agriculture, forestry and horticulture. They are sprayed on plants in the form of fine mist or powder. Most of the pesticides are broad spectrum and effect all types of life. They are, therefore, also called “biocides”. Pesticides reduce the population and number of species of living organisms including micro organisms, thus effect the structure and fertility of soil. Several pesticides or their degradation products are absorbed by plants which in turn may affect the entire food chains and food webs.

(iii) Fertilizers and manures: Chemical fertilizers are added to the soil for increasing the crop yield.  The excretory products of people and livestock and digested sewage singe used as manure pollute the soil. The innumerable pathogens contained in these wastes contaminate the soils and vegetable crops and cause serious health hazards for man and domesticated animals. However, biological sources are the minor factors in altering soil composition.

(iv) Discarded materials: A large number of discarded materials are dumped on the soil by man. These include concrete, asphalt, rugs, leather, cans, plastics, glass, discarded food, paper and carcasses. The addition of solid wastes is sometimes called the third pollution.

(v) Radioactive wastes : Radioactive elements from mining and nuclear power plants, find their way into water and then into the soil.

(vi) Other pollutants : Many air pollutants (acid rain) and water pollutants ultimately become part of the soil. The soil also receives some toxic chemicals during weathering of certain rocks.

 

Write an essay on Radio Active Pollution ?

Radiation is a special type of physical phenomenon in which energy travels through space. That radiations have a direct impact on the living systems was first shown by Roentgen. He interposed his wife’s hand between a vacuum tube and a fluorescent screen and saw the bones. Later on, Becquerel burnt himself with a natural radioactive substance -. radium. Subsequently P.Curie and M.Curie (husband and wife) succeeded in extracting and purifying radium and they also showed its biological implications.

Sun is the main source of radiations such as infra-red, UV-rays Xrays, cosmic rays etc. thus environmental radiations are of two types; (1) natural and (2) man-made.

Radiations can also be broadly categorized into two groups: (i) non ionizing such as UV-rays that do not penetrate deep into the body tissues; and (ii) ionizing such as X-rays, a-rays, B-rays, protons, neutrons etc. that penetrate deep into the body tissues.

Man-made Sources of Radio Active Pollution

Man-made Sources. They include mining and refining of plutonium and thorium and explosion of nuclear weapons, nuclear power plants and fuels and preparation of radio-active isotopes.
(i) Atomic explosion (Nuclear fall out) : Atomic explosions are performed to test the nuclear arms. The nuclear arms use uraniurn-235 and plutonium-239 for fission and hydrogen of lithium as fusion material. Atomic explosions produce radioactive particles that are thrown high up into the air as huge clouds. These particles are carried to long distances by wind and gradually settle over the earth as fall out or are brought down by rain. The fall out contains radioactive substances such as strontium-90, cesium-137, iodine -131 and some others. From the soil, these materials are absorbed by plants and reach animals and man through food chains. From [and radioactive materials are wasted to water sources.
The explosion of first atomic bomb was done in Nagasaki and second in the Hiroshima in Japan in 1945, which caused large scale destruction of human, animal and plant life. In spite of this great tragedy, the big powers are still engaged in the race for nuclear arms. The present stock pile c weapons is enough to destroy the earth completely.

(ii) Reactors and nuclear fuels : Radioactive isotopes such as uranium- 235 are used as fuel to bring about disintegration of other atoms. The process releases large amount of energy as heat, which is used to produce steam for turning large turbines to produce electricity. Both the fuel elements and coolants contribute to radiation pollution. The biggest problem is the disposal of radioactive wastes, which contain excess of fission and activation products. The radioactive wastes are dumped in underground tanks for natural decay. If they escape, they pose grave public health hazards. Inert gases and halogens escape as vàpours and become potential pollutants of the environment by settling on ground or reaching surface waters by rain. People working nuclear reactors, fuel processors, power plants or living nearby are vulnerable to radiation exposure.

(iii) Radioactive isotopes : A large number of radioactive isotopes such as 14C, 125I 32P and their compounds are used in scientific research. These radioactive materials reach water sources with waste water from laboratories. Some of these isotopes such as radioactive iodine and phosphorus enter human body through food chains.

(iv) Radiation therapy: Human being voluntarily receive radiations from diagnostic X-rays and radiation therapy for cancers.

Effects of Radiations of Living Systems

1. Non-ionising radiations may be lethal to micro-organisms but are capable of injuring only the superficial tissues of higher plants and animals.

2. Radiations induce mutations and break in chromosomes particularly at the time of cell division.

3. Radiations damage various tissues of the animal body like epithelial linings of skin and intestine, blood forming cells in the bone marrow, reproductive cells etc. Immediate effects of radiations are nausea, vomiting, diarrhea, eventually loss of appetite and weight. Higher doses of radiations may cause ulceration of intestine, anaemia, leucopenia and sterility. Excessive use of X-rays causes death of the tissues. Young and growing tissues are more susceptible to radiations

4. In plants, chromosomal aberrations are induced by mutations This not only brings about morphological deformities but also reproductive malfunctioning leading to sterility. Different doses of radiations have different effects on different plants. For example; come plants can tolerate a dose of 3,000 rads but show reduced yield; young pine trees are destroyed with a dosage of 500 rads; onion plants can resist up to 25,000 rads. In general, seeds are more resistant to radiations.

5. The atomic explosion by the Allied Forces of U.S.A. on the two cities of Japan-Hiroshima and Nagasaki in 1945 during World War II had caused havoc and ruined these cities. This explosion killed all the innocent people, plants and animals. The radiations were so enormous that even after many years, the newborn babies were abnormal around these two cities.

Write an essay on Water Pollution ?

The contamination of water with harmful chemicals and radiations is called water pollution. There are various causes of water pollution including:
(i) Many industries and factories are built near the banks of rivers, lakes etc. as such water gets polluted.
(ii) The atomic explosions in seas spread radio active waste which pollute the water.
(iii) In some cities, sewer lines pour human and animals waste and garbage from the city into nearby river or other water body so water gets polluted.
(iv) In villages people wash their dirty clothes, take bath and clean their utensils in the pond, lake, or near open wells. So water gets polluted.
(v) Nuclear power reactors discharge radio active wastes and hot water in rivers. So water gets polluted.

Control of Water Pollution
Water pollution can be checked or at least minimized by the following measures:

1. The sewage should be suitably treated before releasing it into water. It is one of the most important means to recover usable water from the sewage. It involves three steps:
(a) In the first step primary treatment stage, the larger and suspended particles are removed by simple physical methods such as sedimentation and filtration.
(b) In the second step ox secondary treatment stage, air is supplied to promote bacterial decomposition of the organic matter followed by chiorintion to kill’the germs.
(c) In the third step or tertiary treatment stage, the salts like nitrates and phosphates are removed by precipitation technique. Many developing countries follow only the first two steps as the third step is quite expensive.

Three stages of sewage treatment: The primary stage removes solid material. In the second stage, organic wastes are decomposed by micro organisms. Tertiary treatment removes minerals that may case cutrophication.

2. The industrial effluents should be suitably treated before releasing pollutants. For example, the acids and alkalies can be neutralized, the colloidal materials can be coagulated, while the metallic salts can be precipitated.

3. Hot water should be cooled before release from the power plants.

4. Washing clothes and taking bath directly in tanks, streams and rivers, which supply drinking water, should be prohibited.

5. Excessive use of fertilizers and pesticides should be avoided and as far as possible less stable pesticides should be used.

6. Water hyacinth (an aquatic weed) can purify water by taking some toxic materials and a number of heavy metals from water.

Write an essay on Noise Pollution ?

What is Noise Pollution ?

Noise Pollution : Another serious threat to the quality of man’s environment is noise pollution. Noise can be defined as unwanted sound. So noise pollution is unwanted sound dumped into the atmosphere without regard to the adverse effects it may have.

In our country urbanization, and industrialization have become twin problems. Cities and towns have sprouted up where industries are concentrated. Lack of town planning has led to residential, commercial and industrial areas being mixed up. Houses, schools and hospitals are situated near industries. All the ‘boons’ of industrialization and civilization such as motors, horns, heavy and light machinery, work and movement, blaring radios, supersonic aeroplanes have become disturbing and irritant.

Effects of Noise Pollution

Constant noise disturb a man physically and mentally. It can cause the blood vessels to contract, skin to become pale, muscles to constrict and adrenaline to be shot into blood streams with consequent rise in blood pressure. This can produce tension and nervousness.

High intensity sound emitted by many industrial plants, bottling machines, supersonic aircraft, and loud speakers and loud speakers when continued for long periods of time not only disturbs but also permanently damages hearing. Offices, industries and crowded places where constant noise prevails can produce temper tantrums, headaches, fatigue and nausea.

Loud and sudden noise affects the brain. Intermittent noise is also very disturbing and harmful. Recent research on the effect of jet noise has shown alarmingly, that in areas subjected to constant barrage of sound from the aeroplanes, there is a much higher incidence of psychiatric illness and also a danger to health of pregnant mothers and small infants. Noise can temporarily diminish sexual feelings.

Tests on a bottling plant revealed that those who worked there for four years were beginning to suffer from deficiency in hearing. Usually workers in noisy factories develop a ringing sound in their ears.

Noise has harmful effects on non-living materials too. Numerous examples can be cited where old buildings and even newly constructed buildings have developed cracks under the stress of explosive sound.

Control of Noise Pollution

For controlling the noise pollution, several methods have been suggested.

(i) In metropolitan areas green belt vegetation and open space in general may have as great value in noise control as in air purification: It has been seen that plants are efficient absorbers of noise, especially noise of high frequency. Border planting along high ways and streets can be effective not only in absorbing the noise but also deflecting it upward in the air.

(ii) Specific legislation and regulations should be proposed for designing and operation of machines, vibration control, sound-proof cabins, sound- absorbing materials, methods for measuring noise, permissible levels of noise and medical examination.

(iii) The enclosure of machinery with sound-absorbing materials is an example of the industrial noise reduction pattern already practiced by industries in advanced countries. Protection to workers can be provided through wearing devices such as ear-plugs or ear muffs.

(iv) Within a radius of 10 miles of airport, no buildings or factories should be allowed. A big green belt around the airport should be planted.

What is Noise Pollution ? What are the effects of Noise Pollution?

Meaning of Noise Pollution

Sound is a normal feature of our life. It is a main mean of communication and entertainments Sound is also one of the effective alarm system in many animals. A loud, unwanted or unpleasant sound that causes discomfort is called noise. A given sound may appear music to some one and noise to others. It depends upon loudness, duration, rhythm and mood of a person. ‘The release of unwanted sound in the atmosphere is called noise pollution’. It causes physical form of pollution that affects man directly, without affecting the lite supporting systems : air, water and soil.

Effect of Noise Pollution

Noise pollution affects the power of hearing as well as general health of man.

(a) Effect on hearing ability: The most immediate and acute effect. of noise pollution is impairment of hearing.

(i) Ear drum may be damaged by sudden loud noise or prolonged exposure to noise.

(ii) The noise in cities is often enough to deafen people gradually at least partially as they age.

(iii) The sensory cells meant for hearing in our ears may be permanently damaged, if they are subjected to repeated sounds of high intensity before their recovery.

(b) Effect on general health : Following adverse effects on health are caused by noise pollution.

(i) Noise cause anxiety and stress and in extreme cases may lead to fright.

(ii) Noise causes digestive spasms and dilation of eye pupil, impairment of night vision and decrease in the rate of color perception.

 

(iii) Constant exposure to noise causes hormonal imbalance leading, to several disorders such as increased rate of heart beat, constriction of blood vessels and increase in cholesterol level producing high blood pressure, hypertension and decreased heart output.

(iv) Noise also detracts attention and causes emotional disturbance.

(v) A sudden high intensity noise produces a startle reaction which may affect psychomotor performance of a person and even heart failure in a heart patient.

(iv) Damage to heart, brain and liver has been reported in animals due to prolonged noise pollution.

(c) Other effects : Noise interferes with our conversation, disturbs concentration and upsets mood.

Write short note on effects of Pollutants on Plant ?

Effect of Pollutants on Plant

Significant and sometimes devastating effects of an pollutants have been recognized on plants. Thick smog has killed more than a million trees in Southern California. The visible injury symptoms on plants and their leaves are discussed as follows:

(i) Tissue collapse and necrotic patterns : This is caused due to plasmolysis of cells of leaves by air pollutants. Initially plasmolysis changes the water relation and finally interrupts the structural integrity which leads to the coil apasing of the tissues. The degree of tissue collapse and appearance of necrotic pattern depend upon the nature of pollutant and its concentration.

(ii) Chlorosis and other colour patterns: Chlorosis is the loss or reduction of chlorophyll in leaves, resulting in the appearance of pale green or yellow patches. Sometimes other colours develop from pigments already present but normally masked by the green pigment. The bleaching is associated with sulphur dioxide and brown pigment it develops with fluorides. Chlorosis often appears in association with collapsed tissue.

(iii) Growth alterations : As a result of air pollution poor growth is also seen. This results in drooping of leaves, stunted growth and small fruits. Ethelene induces epinasty or drooping of leaves and prostate.plants.

Explain the ill effects of Air Pollution on human health ?

Effects of Air Pollution on human Health

The effect of particulate pollutants depends upon the fate of the particles in our body. Particles more than 2 urn are trapped in nasal hair and bronchial mucüs and coughed out or swallowed. The smaller particles enter the alveoli, where they may be engulfed by the special cells or absorbed in the blood. The effect of gaseous pollutants depends upon their solubility in water, which allows their diffusion into the tissues.

(i) Dust, soot and smog cause several respiratory troubles such as bronchitis, asthma, emphysema and lung cancer. Lung diseases are four times more in urban settlements than rural areas. Cotton dust produce lung fibrosis or pneumoconiosis also called byssinosis. Pneumoconiosis also affects the coal miners and flour mill workers. Lung fibrosis produced in the workers of some other industries include asbestosis (asbestos industry). Silicosis (stone grinding), siderosis (iron mill) etc.

(ii) Fly ash and metal dusts cause headache, loss of appetite, dizziness, insomnia, amaemia, weakness and miscarriage.

 

(iii) Air borne organic materials such as spores, pollen, bacteria, fungi, fur, feathers cause several diseases and allergic reactions or hay fever. Common plants which produce allergic pollen are Amaranthus spinosus, Chenopodium album, Cynodon dactylon. Ricinus communis, Sorghum vulgure, Prosopis chilensis etc.

(iv) Sulphur dioxide causes drying of mouth, sore throat and eye irritation. It may damage the tissues by forming sulphuric acid.

(v) Sulphur trioxide, nitrogen oxide and carbon monoxide combine with hemoglobin of the blood and reduce the oxygen carrying capacity of the blood. Inhaling of carbon monoxide also lead to giddiness, exhaustion, reduced vision, nervous and cardiovascular disorder and even death. Such symptoms are quite common at the time of traffic jams or the busy roads. Nitrogen oxide is comparatively less soluble, but at high concentrations it impairs the functioning of lungs causing accumulation of water in air spaces.

(vi) Ozone is formed in the atmosphere by photochemical reaction. Though in the stratosphere it protects the earth from high energy ultraviolet radiations. But in the lower atmosphere, it produces chest pain, coughing and eye irritation.

(vii) Depletion of ozone layer exposes the earth to increased ultraviolet radiation. This may have adverse effects such as increased skin cancer and mutation rate in general.

(viii) Many hydrocarbons induce cancer.

Write an essay on Air Pollution ?

Air pollution may be defined as ‘the presence of materials in the air in such a concentration, which are harmful to man and the environment’. In other words ‘the occurrence or addition of foreign particles, gases and other pollutants into the air, which have an adverse effect on human beings, animals, vegetation, buildings and other objects is called air pollution’.

Atmospheric pollution is complex in origin and varied in effect. It may be natural or man made. Natural air pollution has been occurring before the man came on the scene. Volcanic eruptions, forest fires, natural organic and inorganic decays let out large quantities of harmful dust and gases. It is estimated that out of the total annual emission of 1 x 10 tonnes entering the earth’s atmosphere only 5 x .10 tonnes (0.05 per cent) is contributed by human activities. Air pollutants resulting from human activities are mainly discharged in over populated cities and industrial centres. This pollution may be marginal in global terms, but it has serious effect locally. Many pollutants do not rise above 600 meter of earth’s surface or at least become highly diluted. The movement of the air pollutants is restricted due to certain physical barriers. This leads to high concentration of the pollutants in certain areas.

Causes of Air Pollution

Important causes of air pollution are power and heat generating system, producing large quantity of waste gases, use of insecticides and fungicides etc. Some of them are as follows

1. Exhaust gases : Exhaust gases are the products of fuel combustion which come out with the smoke from the chimneys of factories and from automobiles. These invisible exhaust gases contain gases like carbon monoxide, sulphur di-oxide, hydrogen fluoride, hydrogen sulfide, nitrogen and heavy metals, such as copper, zinc, lead and cadmium, etc. These heavy metals and gases are injurious to all the livings. Motor vehicles alone contribute about 60% of air pollution, carbon monoxide causes difficulty in breathing, caused irritation in mucous memberanes, combines with blood haemoglobin reducing its oxygen carrying capacity and causes asphyxiation. High concentration of it may cause even death of man.

Another fatal hydrocarbon released due to incomplete combustion of petrol is 3-4 benzyprene which is responsible for causing lung cancer. Similarly exides of nitrogen may cause irritation in eyes and nose, and may cause acute respiratory diseases such as asthma and lung cancer.

2. Smoke and Grit : Smoke is the visible product of incomplete combustion and is accompanied with other gases, formed during combustion. It is responsible for 10-15% atmospheric pollution. The smoke and grit coming out from the domestic hearths and factories also cause considerable harm to life. One of the most harmful effects of smoke is the smog formation which makes fog heavier and darker by it. Hydrocarbons and nitrogen oxides when presence of UV-radiation in sunlight. This is turn causes photochemical smog which is responsible for causing eye-watering, and respiratory distress in human beings. It is toxic to plants also. This smog blocks reaction of photosynthesis.

(3) Radio-active substance: Radio-active elements are emitted as byproduct of atomic explosions, testing nuclear explosions, etc. Such elements emit high energy radiations : the ionizing radiations which remove electrons from stable atoms. Some of them have very long half life period; (i.e. Calcium- 45-160 days: Strontium 90 and Cesium : 137 days) and are most toxic isotopes to man and other animals.

(4) Insecticides : The excessive use of insecticides has caused grave pollution problems. The pesticides like aldrin, lindane chlorodane diendrin, DDT, toxaphene, etc. are commonly used for destroying pests and insects from agriculture crop. Though they have enormously increased our agricultural production, their unplanned and extensive use have caused grave pollution problems. Similarly some of them enter in the environment as spray dusts of the chlorinated hydrocarbons (such as DDT), polychlorinated biphenyls etc. are most dangerous.
Insecticides also kill several useful aquatic food organisms when sprayed on water bodies. It destroyed their larvae and also decreases the photosynthetic power of marine phytoplankton.

(5) Herbicides: Herbicides are used for clearing the railroad and highway weeds, weed control in agriculture and forest management. However their continuous use is causing hazards in our life. Some of them, as monuron and simazin etc. affect photosynthetic activity of plants, 2-4, D and 2, 4, 5 T cause cell proliferation in phloem and finally causes blockage of food passage. From plants, these herbicides enter into animals and cause skin disease, constriction of stomach muscle etc. Hence, they affect both producers and consumers.

Effects of Air Pollution

Our health depends on the quality of air we breathe in our immediate environment. Foul air had been held responsible for various health hazards and diseases. Air borne spores, pollen grains, bacteria, fungi, fur, hair etc. cause various allergic reactions, bronchial asthema, tubeculosis and other infections. With rapid increase in industries and vehicular traffic, the air of Indian cities is becoming increasingly polluted. The data regarding the quality of air over selected Indian cities.

(A) Effects on Vegetation
Air pollution causes wide spread damage to plants.

(i) Dust, smoke and other particulate matter reduce sunlight and settle on the leaves of plants, thereby retard photosynthesis.

(ii) Sulphur dioxide causes chlorosis, plasmelysis, membrane damage and metabolic inhibition. The leaves often assume water soaked appearance. Fruit trees and cereal crops are more sensitive to oxides of sulphur. Therefore they suffer a great loss in the areas around smelters and industrial belts.

(iii) Fluorides destroy tissues in leaves causing necrosis of leaf margins and tips.

(iv) The photochemical smog leads to the bleaching and blazing of foliage.

 

(v) Hydrocarbons such as ethylene cause premature leaf fall, fruit
drop, shedding of floral buds, curling of petals and discolouration of sepals.

(vi) Ozone damage chiorenchyma and thus destruct the foliage in large
number of plants.

(vii) Lichens are very sensitive to air pollution. Their growth is inhibited in polluted air.

The death of lichens in an area is an indicator of air pollution.

(B) Effect on Animals

Air pollution causes large scale damage to live stock. The general effects of air pollution on domestic animals in or around industrial area are similar to those on human beings.

(i) Ingestion of fluorine compounds deposited from the air on fodder causes fluorosis (excessive calcification of bones and teeth). It also results in lameness, frequent diarrhoea and loss of weight.

(ii) Several air borne microbes cause diseases.

(C) Deterioration of Materials

(i) Oxides of sulphur and nitrogen and products of photochernical
smog have deteriorating effect on buildings, metals, textiles and marble.

(ii) Acid rains produced by oxides of sulphur and nitrogen have
corrosive effect on the buildings and other materials.

(iii) Large number of historical buildings are damaged by acid rains and other air pollutants. It is feared that the famous marble monument Taj Mahal at Agra is under acute danger of air pollution. Many industrial units have been shifted to save the precious monument.

(iv) Hydrogen sulphide discolour silver and lead paints.

(v) Ozone has deteriorating effects on rubber goods.

(D) Aesthetic Loss

Air pollution has strong bearing on the aesthetic side of human life.

(i) A clear and transparent atmosphere is not only aesthetically pleasing but is necessary for clear vision. A dust haze or hanging smoke blurs our views.

(ii) Foul odour emitted by industries, automobiles, dirty drains and garbage heaps make urban life unpleasant.

(iii) Coal dust and their materials discharged from the industries settle down on the floor and other objects of houses and give dirty look.

(E) Effect on Climate

Earth’s climate depends on various factors including composition of atmosphere and balance of gases. Therefore, air pollution may bring about harmful effect on the climate.

(i) Heat produced by the industrial plants raises the temperature of the area.

(ii) Carbon dioxide content of the atmosphere is increasing due to destruction of forests and excessive burning of fossil fuels and is likely to be doubled by 2020. It will lead to rise in global temperature by more than two or three degree due to green house effect. A rise in global temperature may result in melting of glaciers and polar ice caps, flooding of low lying coastal plants and• submersion of islands. Rainfall pattern may also change, thus affecting agricultural output.

(iii) Aerosols and nitrogen oxides deplete ozone layer in the stratosphere, which permit most of the harmful ultraviolet radiations to reach the earth.

Control Measures of Air Pollution

1. It is easier to control air pollution from the point of sources e.g. factory chimney, etc. Air pollution can also be removed by observing the certain principles. ft needs modification and improvement in some of our air pollution causing industrial processes. Pollution control equipments for monitoring the air pollution are available in market and can be installed in factories. It would minimizes the pollution to some extent.

2. Sulphur-dioxide gas which is highly injurious for human health, its pollution can be controlled in two ways, one by removing sulphur after burning, or secondly by clesulphurization of fuel before its use. Our conventional energy fuels are how being replaced by non-conventional area such as electricity and natural gases which do not produce sulphur gas. The non-combustive modes of energy production such as, tidal power, geothermal power, solar power etc. have replaced the old systems which emitted in production of large quantity of sulphur gases: By cleaning up of combustion also, we can reduce air pollution. Nuclear power which has been looked upon as an alternate to conventional energy producing device, however, produces some thermal pollution.

3. Emission from motor vehicle may be limited by cleaning the exhaust gases after combustion by using some catalyst. Introduction of efficient motor engines which could burn the fuel completely will also reduce this pollution.

4. Use of tall chimneys which will release the waste gases at a much
higher level can also reduce the pollution.