CHAPTER-2
ENVIRONMENTAL ISSUES
Learning Card -1
I choose the correct answer
1. Identify from the following a bio degradable pollutant
a) Oxides of Sulphur b) Sewage water c) Lead compounds d) Pesticides.
2. Which of the following is the most hazardous air pollutant?
a) Oxides of Nitrogen b) carbon dioxide c) carbon monoxide d) oxides of sulphur
3. Which of the following chemical element responsible for breaking down ozone in the atmosphere
a) mercury b) carbon c) lead d) chlorine
4. Cigarette smoke has a high content of
a) carbon dioxide b) hydrocarbons c) sulphur dioxide d) carbon monoxide.
II Answer the following questions
1. What are biodegradable pollutants? Give one example.
Such pollutants that can be degraded by biological activity are called biodegradable pollutants. Eg : Sulphur Dioxide.
2. What are Non – biodegradable pollutants? Give one example.
Such Pollutants which cannot be converted into harmless constituents are called non – biodegradable Pollutants. Eg : DDT
3. What is air pollution?
Any human activity that brings about significant changes in the atmosphere is called air pollution.
4. What is sound pollution?
Any sound which causes unpleasant effects and discomfort to human ears is called sound pollution.
5. What is radioactive pollution?
Emission of protons, Electrons and Gama rays due to disassociation of atomic nuclei of some elements. Such emissions also cause pollution called radioactive pollution.
III Answer the following questions
1. Mention any four reasons for air pollution.
Coal Combustion
Diesel Combustion
Petrol Combustion
Smoking of Tobacco.
2. Mention any two reasons for water pollution.
Industrial Effluents.
Sewage Water
3. Write any two reasons for radioactive pollution.
Mining and refining of radioactive substances like uranium and thorium.
Disposal of nuclear wastes.
4. Name the pollutants responsible for underground water pollution.
Lead, Arsenic and fluoride
5. Mention any four sources of sound pollution.
The gadgets used at home like mixer and grinder.
Transport vehicles especially aircraft
Commercial and industrial Activities.
Social and Public events.
6. Mention any two reasons for Soil pollution.
Chemical fertilizers
Residues of pesticides
Learning Card -2
I. Choose the correct answer and write.
1. Agricultural wastes are causing.
a.)Water Pollution b) Soil Pollution c) Air Pollution d) both water and soil pollution.
2. Global warming can be reduced by minimising the release of.
a) Chlorofluro carbons b) Sewage water c) Greenhouse gases d) agricultural wastes
3. Noise that hampers human hearing system is.
a) above 100 decibles b) 75 decibles c) 50 decibles d) less than 25 decibles
II. Answer the following questions.
1. Expand CFC.
Chlorofluro carbons
2. What is greenhouse effect?
The infra-red rays released due to the heating of the earth by solar radiation, are trapped by some gases in the atmosphere. This results in increase in the atmospheric temperature. This increase is called greenhouse effect.
3. What Acid rain.
When oxides of sulphur and nitrogen in the atmosphere combine with water vapour and form sulphuric acid, nitric acid respectively. These precipitate as acid rain.
4. Name any two substances responsible for depletion of ozone layer.
a) chlorofuro carbons. b) insulating foams.
5. Write any two effects of carbon monoxide on human health.
Asphyxia leasing to heart and nervous system damage, death.
6. What are the effects of Global warming?
Global warming has resulted in melting of the glaciers, causing an increase in the sea level. As a result flooding of sea water is increasing. This results in submerging of lands. Hence it affects both aquatic and land life.
7. Write the effects of sound pollution.
* Noise Pollution directly affects the human nervous system causing deafness, headache, high blood pressure and heart disorders.
* Noise causes behavioural discomforts. Noise pollution seriously affects animals also.
8. What is the difference between biodegradable and non-bio degradable pollutants?
| biodegradable | non-bio degradable |
| Pollutants that can be degraded by biological activity are called biodegradable pollutants. Example: sewage | Pollutants which cannot be converted into harmless constituents non-biodegradable pollutants. Example: DDT (dichlorodiphenyltrichloroethane) |
9. What are the steps followed in sewage water treatment?
Sewage water must be treated to remove suspended particles. It must be aerated and then chlorinated to purify water. This water can be reused.
10. The Government has prohibited selling of Gutka. Why?
Gutka has toxic chemicals that can affect the health seriously.
Learning Card -3
I. Chose the correct answer :
1. Acid rain refers to precipitation with Ph of
a) less than 5.6 b) about 7.0 c) above 6.0 d) above 7.0
2. A worker working in copper smelters has lung cancer. The pollutant responsible for this is
a) Carbon monoxide b) Arsenic c) Allergens d) Sulphur oxides
3. The rays that penetrate through the skin and destroy cells are.
a) Beta rays b)gamma rays c) alpha rays d) radio waves
II. Answer the following questions
1. What is thermal Pollution?
Many industries use high temperature furnaces and boilers in their manufacturing processes. The resulting hot effluents are directly released into a nearby water sources. This is called thermal pollution.
2. What is marine pollution?
Many of the pollutants reaching the atmosphere, condense and fall into oceans and seas cause marine pollution.
3. What is the effect of the air pollutant Asbestos on human health?
Asbestos effects human beings causing Asbestosis.
4. Suggest measures to control air pollution.
* Industries to be established away from towns and cities
* Emissions from industries to be checked and controlled.
* Automobiles to be periodically checked to improve the efficiency of engines to minimise the emission.
* Use of unleaded fuel and biofuels must be encouraged.
* Educating the public to use public transport.
5. Suggest measure to control water pollution?
* Industrial effluents must be suitably treated to remove the pollutants. Toxic chemical substances must be eliminated Acids and alkalies must be neutralised.
* Effluents coming from furnaces must be cooled to room temperature and treated before being released.
6. What are the effects of mutation?
*In human beings, the inheritance of skin cancer and cataract increases.
* In plants and animals, it can affect growth and physiological functions.
* It affects the population ratio of phytopkinktons causing serious imbalance in the ecosystem.
7. How can Industrial waste be treated?
Industrial effluents must be suitably treated to remove the pollutants Toxic chemical substances must be eliminated. Acides and Alkalies must be neutralised, Metallic compounds must be precipitated.
8. Give suggestions to control acid rain.
* Industrial fuels must be without pollutants. * Use of automobiles be reduced.
9. The length of the smoke pipe in industries should be increased. Why?
Increase in the length of smoke pipe in industries control ground level air pollution.
10. Ramesh Roa has decided to shift their house from the heart of the city to out skorts of the city. Give scientific reason.
In the heart of the city due to increased automobile air pollution is high with CO2. Whereas at the out skorts of the city air pollution is less.
11. The seedling of vegetable plants are grown inside a green house. Why?
Inside the glass house plants get suitable environment on account of high temperature.
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2-environmental_issues-lc_em-3.pdf
Source: Schooleducation.kar.nic.in
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