Question

Direction: It consists of two statements, one labelled as ‘Statement (I)’ and the others as ‘Statement (II)’. You are to examine these two statements carefully and select the answer using the codes given below:

Statement (I): Normally carbon dioxide is not considered an air pollutant. 

Statement (II): Carbon dioxide is a constituent of atmospheric air.
1.

Both Statement (I) and Statement (II) individually true and Statement (II) is the correct explanation of Statement (I)

2. Both statement (I) and Statement (II) are individually true, but Statement (II) is not the correct explanation of Statement (I)
3. Statement (I) is true, but Statement (II) is false
4. Statement (I) is false, but Statement (II) is true

Answer 1

Correct Answer - Option 1 :

Both Statement (I) and Statement (II) individually true and Statement (II) is the correct explanation of Statement (I)

The major air pollutants are:

• Carbon monoxide
• Lead
• Nitrogen dioxide
• Ozone
• Particles
• Sulfur dioxide

 

Carbon dioxide is not considered as an air pollutant as is a constituent of atmospheric air and it is not harmful to ordinary things, human beings, or to animals, or to plants. It is actually needed for plant growth.

Therefore, both Statement (I) and Statement (II) individually true and Statement (II) is the correct explanation of Statement (I).

Important Points:

Air pollutants are classified into primary pollutants and secondary pollutants.

Primary pollutants:  Pollutants that are emitted directly from either natural events or from human activities are called primary pollutants.

The natural events are dust storms; volcano etc and human activities can be emission from vehicles, industrial wastes.

About 90% of global air pollution is constituted by five primary pollutants. These are

1. Carbon monoxides (CO)

2. Nitrogen oxides

3. Sulphur oxides

4. Hydrocarbons

5. Particulate matter

6. Volatile Organic Compound

7. Suspended Particulate Matter (SPM)

8. Radioactive compound

9. Halogen compound

Secondary pollutants: Primary pollutants when reacting with each other or from basic components of air, forms a new pollutant called secondary pollutants.

Different types of secondary pollutants include:

1. Ozone (O3)

2. Sulfuric acid and nitric acid (a component of acid rain)

3. Particulate matter

4. Nitrogen dioxide (NO2)

5. Peroxyacyl nitrates (PAN)

6. Photochemical smog