Social science class 8 chapter 18 exercises Question answer
Answers
. What are the different ways in which water gets contaminated ?
Soln:
The different ways in which the water gets contaminated are:
i) Industrial waste: The harmful chemical wastes gets released by the industries into water sources .
ii) Sewage waste: kitchen, laundry and toilets release the waste materials and this pollutes water.
iii) Agricultural chemicals: Excessive amount of pesticides and fertilizers are used by the farmers for enhancing crop production. Rains and floods carry these harmful chemicals to water bodies which results in pollute water pollution.
2. At an individual level, how can you help reduce air pollution?
Soln:
The following are the steps we can take for reduction of air pollution:
i) We should avoid the usage of personal cars and opt for public transport as much as possible.
ii) We should properly dispose of the garbage and not burn it.
iii) For shorter distances, avoid vehicles.
iv) We should control the number of emissions from household chimneys and vehicles.
v) We should replace our vehicle fuel, diesel and petrol by LPG and CNG.
3. Clear, transparent water is always fit for drinking. Comment.
Soln:
No, we don’t agree to the statement that clean water is always fit for drinking because water might appear clean but it may contain some disease-causing micro-organisms and several other dissolved impurities. Hence, we advise purifying the water by boiling or by any purifying system before drinking it.
4. You are a member of the municipal body of your town. Make a list of measures that would help your town to ensure the supply of clean water to all its residents.
Soln:
The following are the measures taken by us to ensure the supply of clean water to our town resident:
a) We clean the area around the water pipes.
b) The main water source has to be built in a clean surrounding and should be maintained properly.