OUR ENVIRONMENT
FILL IN THE BLANKS
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An average human being needs about 14 Kg of air everyday for breathing.
World environment Day is celebrated on 5thjune.
Standard unit of sound decibel
Deforestation should be replaced with afforestation.
Respiratory diseases and lung cancer may be caused by air pollution.
Contamination of water bodies arises from untreated sewage.
We should ensure that garbage is properly incinerated.
Van Mahotsav Day is celebrated on 1st of July.
NAME THE FOLLOWING
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Substance used to protect the crops from insects
Insecticides
Indiscriminate felling of trees
Deforestation
Growing of trees on a large areas
Afforestation
Wearing away of topsoil by natural agents like wind and water
Erosion
Disturbances and disruption of natural conditions
- Pollution
Two pollutants which you would expect to find in water
- lead and mercury
Two pollutants which you would expect to find in the factory smoke – Hydrogen sulphide
and sulphur dioxide
ANSWER THE FOLLOWING
1. What is pollution? What are different types of pollution?
ANS. A naturally occurring or manmade process by which the usually favourable natural
conditions for healthy living are disturbed or disrupted is called pollution
The major forms of pollution are air pollution, water pollution, soil pollution, noise pollution,
and radioactive pollution.
2. What is a pollutant? Give example.
Ans. Any harmful substance or effect which enters our environment causing pollution is a
pollutant. Eg:- Insecticides ,pesticides, carbon monoxide, hydrogen sulphide etc.
3. What are the main sources of air pollution?
Ans. The main sources of air pollution are industries, fumes from automobiles, burning of
domestic fuels, and deforestation.
4. What are silent zones?
Ans. Some areas like hospitals and schools are marked as silent zones where no horns are
allowed. The noise levels of loudspeakers and music systems should be kept in permissible
limits.
5. Explain about radioactive pollution?
Ans. Radiations from outer space, nuclear weapons, nuclear power plants and other electronic
devices may causes cancer and genetic disorder in humans. We can control radioactive
pollution by proper storing of radioactive material in lead chambers and treated the
radioactive waste before disposal.
6. What are the main causes of soil pollution?
Ans. Soil pollution is caused by dumping of solid waste, excessive use of fertilizers or pesticides
and soil erosion.
7. Write some preventive measures for soil pollution.
Ans. Recycle of waste materials.
Use eco-friendly articles.
Garbage should properly incinerate.
8. How we can control noise pollution?
ANS. Vehicles should not use their horns unless necessary.
Reduce the noise levels of loudspeakers and music systems.
Talking softly and politely to each other rather than shouting.
Replace old sound making equipments.
9. Explain the role of trees in maintaining balance between the atmospheric gases.
Ans. During photosynthesis green plants absorb carbon dioxide from atmosphere and release
oxygen into it. This helps in maintaining balance between these two gases. Plants can also
absorb some polluted gases form atmosphere.