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TO SCIENCE PPTON

POLLUTION OF AIR AND WATERBY- VIBEKANANDA

CHAMPATI CLASS – VIII (B)

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POLLUTION The presence of unusually high concentrations of harmful or poisonous substances in the environment is called POLLUTION. Pollution contaminates the air and water with poisonous substances and makes them impure to such an extent that they become harmful to the human beings, other animals, plants as well as to the non-living things. Pollution are of three types.SOLID WASTE

POLLUTIONWATER POLLUTION

AIR POLLUTION

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POLLUTION , WHAT DOES IT LOOK

LIKE ?

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AIRAir is mixture of gases. The two main gases present in air are Nitrogen & Oxygen. Nitrogen makes up to 78% of the air whereas oxygen makes 21% of the air and the remaining 01% is occupied by co22, water vapor, argon and other gases. In addition to the normal constituents polluted air may also contain some harmful gases such as carbon monoxide, sulphur dioxide, nitrogen oxides, dust, smoke, etc.

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78%

21%

1%

COMPOSITION OF AIR

NITROGENOXYGENOHER GASES

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The air over large cities is contaminated with harmful gases like sulphur dioxide, nitrogen oxides, carbon monoxides, smoke & dust etc. The contamination of air with harmful gases, smoke and dust etc is called as Air Pollution .The substance whose presence in the air makes it impure or contaminated is called an Air Pollutant.The major pollutants which causes air pollution are sulphur dioxide, nitrogen oxides , carbon monoxides, excess of carbon dioxide, chlorofluorocarbons, and suspended particles.

AIR POLLUTION

AIR POLLUTION

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CAUSES OF AIR PLLUTION How WHYA cloud of smoke from the exhaust of a vehicle

Increasing traffic

Smoke from a factory chimney

Growing cities

Eruption of a volcano

Rapid economic development

Cigarette smoke Industrialization

Burning leaves Apathetic people

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SOURCES OF AIR POLLUTION

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Health problems Damage to the environment Damage to property Thinning of the protective ozone layer of the atmosphere which is leading to climate changes.

HARMFUL EFFECTS OF AIR POLLUTION

HEALTH PROBLEMS

THINNING OF OZONE LAYER

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ACID RAINThe poisonous gases like sulphur dioxide and nitrogen oxide that is released by the industries, by burning fossil fuels, by the vehicles, etc go to the atmosphere and pollute it. The sulphur dioxide reacts with the water vapour to form sulphuric acid and the nitrogen oxide reacts with the water vapour to form nitric acid. These acids get dissolved with the rain water and fall to earth in the form of acid rain.

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EFFECTS OF ACID RAIN

DIRECT DAMAGES TO LEAVES AND ROOTS

TREES GET WEEKENED AND EATEN BY INSECTS

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Acid deposition leaches nutrients from soil and makes toxins

CULTURAL EFFFECTS OF ACID RAIN

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MARBLE & LIMESTONEACIDS BREAK DOWN THESE MATERIALS

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MANY FAMOUS BUILDINGS ARE BEING DAMAGED

LIKE……

THE TAJ MAHAL PARTHENON

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STATUE OF LIBERTYLOSS OF ARTISTIC DETAIL IN ACROPOLIS

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The TAJ MAHAL at AGRA (near Delhi) is a beautiful historical monument made of pure, white marble. The experts have warned that the air pollution around Taj mahal area is discoloring its white marble and also corroding it slowly. This poses a threat to the beauty of Taj Mahal. The acids present in the rain reacts with the white marble and corrode it slowly.

THE CASE OF TAJ MAHAL

THE TAJ MAHAL IS IN GOOD STATE UNAFFECTED BY THE

ACID RAIN.

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TAJ MAHAL IS AFFECTED BY ACID RAIN

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Carbon dioxide gas present in the atmosphere allows the heat rays of the sun to pass through it and reach the earth but prevents the heat rays reflected from earth’s surface and its objects from passing out of the atmosphere into space. In this way, the heat rays remain trapped in the earth’s atmosphere and warm it up. The warming up of the earth’s atmosphere due to the trapping of the heat rays by carbon dioxide gas in the atmosphere, is called Green House Effect.

GREENHOUSE EFFECT

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The air pollution can be controlled by using smokeless fuels like LPG, PNG (Piped Natural Gas).

Solar water heaters should be installed to obtain hot water.

The air pollution from motor vehicles can be reduced by using CNG (Compressed Natural Gas).

The air pollution from factories, industries, thermal power stations, oil refineries, etc can be controlled by washing their smoke and waste gases with jets of water.

The air pollution can be controlled by using non-polluting sources of energy like solar energy, wind energy and hydro energy for generating electricity.

CONTROLLING AIR POLLUTION

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END OF AIR POLUTION

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OUR ROLE IN COTROLLING AIR POLUTION

We should not burn dry leaves, papers and garbage in the open.

We should save electricity. We should grow more trees. We should use utilize the plastic waste materials in

making useful materials. We should use bicycle for covering short distances. We should use 4R’s.

REUSE REDUCE

RECYCLERECOVER

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OUCH ! WHAT HAPPENED TO MY HOME

IT IS DAMAGED DUE TO WATER POLLLUTION

WATER POLLUTION

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Most of the water we use comes from the rivers and the lakes. Everyday many unwanted and harmful substances are thrown ( or discharged ) into the rivers or lakes. This makes the water of the rivers and lakes impure. And we say that the water has been polluted. The contaminated of water of rivers, lakes and ponds, etc., with the unwanted and harmful substances is called water pollution. Water is said to be polluted when it becomes unfit for drinking or bathing. The unwanted and harmful substances which makes the water impure are called water pollutants. In other words, the substances which pollute water are called water pollutants. Pollutants make the water impure. The major pollutants which cause water pollution are : sewage, fertilizers, pesticides, and industrial wastes. All these water pollutants are harmful and dangerous to human beings, animals and plants. Some pollutants can even cause death. Hot water from power plants and industries is also considered a pollutant. This is because when very hot water coming from power plants and industries is discharged into a river or lake, it raises the temperature of the river water. The rise in the temperature of the river water has an adverse effect on the animals and plants living in it.

WATER POLLUTION

Toxic substances dissolve in water or gets deposited on the bed.

Toxic substances enter lakes, rivers, streams, etc.

Pollutants go down into the ground.2

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CAUSES OF WATER POLUTIONHOW SOURCES

City sewage

Industrial waste

Agricultural run-off

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SOME QUESTIONSQ.01. Which of the following is not a greenhouse gas ? (a) Carbon Dioxide (b) Nitrogen (c) Nitrous oxide (d) Methane

Q.02. Drinking water can be made absolutely safe by adding some (a) Aspirin tablets (b) Iodine tablets (c) Chlorine tablets (d) Chlorophyll tablets

Q.03. Which one of the following does not contribute in producing acid rain ? (a) Nitrogen Dioxide (b) Nitrogen Monoxide (c) Carbon Monoxide (d) Sulphur Dioxide

Q.04 The constituent of polluted air which contributes in acid rain is : (a)Nitrogen (b) Sulphur Dioxide (c) oxygen (d) argon

Q.05. The excessive use of one of the following can cause the death of fish in a pond by oxygen starvation. This one is: (a) Fertilizers (b) Manures (c) Pesticides (d) Herbicides

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ANY QUERIES ?

THANK YOU