I. Choose the correct answer:

1. Natural Nutrient enrichment of streams and lakes is Eutrophication

2. The main cause for natural air pollution Volcanic eruption

3. Contamination of air is called Air pollution

II. Answer the following questions:

1. What is Water pollution?

Water pollution is any chemical, physical or biological change in the quality of water that has a harmful effect on any living thing that drinks or uses or lives in it.

2. List out the major Air pollutants.

The source of pollutants is both natural and man-made.

Volcanic eruptions, wind erosion, are the natural causes of air pollution.

The man-made reasons for air pollution are vehicular emission, thermal power plants, industries and refineries.

3. What is Noise pollution?

Human or machine created sound that disrupts the activity or balance of human or animal life is known as noise pollution.

4. What are the major causes of water pollution?

The major causes of water pollution

The first are disease-causing agents. These are bacteria, viruses, protozoa and parasitic worms.

Second pollutant is oxygen demanding bacteria. This causes other organisms in the water such as fish to die.

The third class of water pollutants is water soluble inorganic pollutants such as acids, salts and toxic metals.

5. What is bio diversity?

Biodiversity is the degree of variation of life forms within a given ecosystem.

Acquired land for mining affects biodiversity.

Environmental changes due to mining and dam constructions cause extinctions.

6. How pollution is caused due to bio-medical waste?

Pollution due to biomedical waste is likely to spread diseases dangerous to life.

Eg. The radiation of radio therapy machine cobalt-60 which was sent scarpyard caused death of a scarpyard worker in Delhi hospital.

7 What is meant by pollution due to e-waste?

India produces about 3,80,000 tonnes of e-waste generated out of television sets, mobile phones, computers, refrigerators and printers. This is great threat for human as it is non-degradable

III. Answer the following in a paragraph:

1. What are the effects of acid rain?

The effects of acid rain

  • Acid rains killed more than 70% of corals in Lakshadweep and Andaman islands.
  • Microscopic organisms such as plankton may not survive the food chain will be affected.
  • If ocean temperature increases, growth of coral reefs will be affected.
  • Other ecosystems such as forests and desert will also be harmed.
  • Loss of bio-diversity and extinction of rare species will occur.
  • They also change the acidity level of the soil by leaching crucial nutrients. Thus it affects forest vegetation.
  • Corals control carbon-di-oxide by turning CO2 in water to limestone shell.

2. What is smog? What are the effects of smog?

  • Smog is a combination of the words smoke and fog.
  • It causes a smoky dark atmosphere.
  • It decreases visibility, and creates gaze throughout the area.

Major producers

Automobiles, fires, waste treatment, oil production, industrial solutions, paints and coatings.

The effects of smog:-

  • Smog creates harmful health hazards like lung failure and pneumonia.
  • Smog is not only a city problem wind carry smog away from urban areas and harm other areas too.
  • Agriculture is also affected by smog.

3. Give a brief note on Acid rain.

Acid rain:-

  • Acid rain was first discovered in 1852 in London.
  • Caused by gases given out by automobiles or coal burning by power plants.
  • The gases that cause the acid rain is sulphur-di-oxide and nitrogen oxides.
  • These pollutants combine with water vapour in the presence of sunlight and oxygen and form dilute sulphuric and nitric acids.
  • When these mixture precipitates from the atmosphere, it is called as acid rain.
  • Acid rain falls down to the earth in all forms of precipitation can harm destroy both natural ecosystems and man-made products.
  • Acid rains, killed more than 70% of corals in Lakshadweep and Andaman islands.