NCERT Class 8 EVS Where should the waste go
6. Where should the waste go? Background Different materials decompose, or rot, at different speeds under different conditions. There are materials which do not decompose easily and take a long time. Waste materials are hazardous to the environment if not properly disposed…
NCERT Class 8 EVS Vaccination A shield
11. Vaccination – A shield Background Vaccination is done to protect ourselves from many diseases, such as diphtheria, whooping cough, tetanus, cholera, hepatitis, polio, etc. Today the vaccination drive against polio is very intense. There is an international campaign to…
NCERT Class 8 EVS Saviours of our environment
20. Saviours of our environment Background Environmentalism is a concern for the preservation, restoration and improvement of the natural and social environment. It includes conservation of natural resources, prevention of pollution and sustainable use of land. As responsible…
NCERT Class 8 EVS Quality of soil and crop production
14. Quality of soil and crop production Background Fertilisers are generally used for healthy growth of plants. But the excessive use of chemical fertilisers makes the soil acidic or alkaline. Plants do not grow well when the soil is either too acidic or too alkaline.…
NCERT Class 8 EVS Pollution and diseases
15. Pollution and diseases Background Pollution of different kinds, such as air, water, soil, etc. is increasing day by day all over the world inspite of increasing awareness. The effects of pollution are prominently visible with more and more people suffering from pollution…
NCERT Class 8 EVS Pests Uninvited guests
16. Pests – Uninvited guests Background Different kinds of pests, such as rats, insects, fungus, etc. attack grains in storage whether at home, in grocery shops, granaries, or godowns. This leads to damage and contamination of the grains thereby reducing the amount of grains…
NCERT Class 8 EVS Noise pollution
2. Noise pollution Background There are some natural and some manmade sources of sound. Some sounds may be pleasant while some others may be unpleasant. Chirping of birds, blowing of breeze, rustling of leaves, music are some examples of pleasant sounds. Sounds near place of…
NCERT Class 8 EVS Mosquitoes woes
10. Mosquitoes woes Background It is commonly observed that as monsoon sets in people suffer from many diseases caused by mosquito bites. Some of such diseases like malaria, dengue, chikungunya, etc. are more common in specific periods of the year, such as the rainy season, …
NCERT Class 8 EVS Monitoring of air pollution
18. Monitoring of air pollution Objective Background Most television channels telecast information about different types of air pollutants measured in different cities. Pollution levels vary almost everyday and in different seasons. Methodology 1. Note the pollution level…
NCERT Class 8 EVS Judicious use of water in irrigation
13. Judicious use of water in irrigation Background Irrigation is the artificial application of water to the soil usually for assisting in growing crops. Irrigation has been around for as long as humans have been cultivating plants, although the means of irrigation have…
NCERT Class 8 EVS Judicious use of fuels
8. Judicious use of fuels Background The known reserves of coal and petroleum will last, at most, a few hundred years. It is therefore necessary to use these fuels only when absolutely necessary. This will result in better environment and their availability for a longer…
NCERT Class 8 EVS Hazards of air pollution
19. Hazards of air pollution Background It is often reported that electronic gadgets like televisions, music systems, microwave systems and computers in households located near large open drains, which carry polluted water, have a shorter than expected life of the brand.…
NCERT Class 8 EVS Global warming
3. Global warming Background Greenhouse gases trap radiation and prevent heat from leaving the earth’s surface. In the process they help to maintain the temperature of the earth. Excess presence of these gases in the atmosphere causes global warming. Methodology 1. Take two…
NCERT Class 8 EVS Fossil fuel is not forever
7. Fossil fuel is not forever Background Fossil fuels which are one of the basic sources of energy for all our activities are exhaustible. For example, coal, kerosene, and LPG are sources of energy for cooking, heating, burning in our households. Petrol and diesel used for…
NCERT Class 8 EVS Estimation of particulate pollutants in air
4. Estimation of particulate pollutants in air Background Solid particles and liquid droplets present in air are called particulate matter. Their presence in air beyond a certain limit is one of the causes of air pollution. Dust particles, pollen grains, smoke, vehicular…