Question

smoke,dust,sulphur dioxide and nitrogen dioxide are major sources of pollution of

(a)soil

(b)water

(c)air

(d)noise​

Answer 1

(c) Air.

• The substances which contain the  air is called air pollutants.
• This substance comes from natural  sources like smoke and dust arising from  forest fires or volcanic eruptions.
• Pollutants may also happen due to human activities.
• Factories , power plants,  automobile exhausts and burning of  firewood is an example of air pollutants.
• We already know that air consists  of a mixture of gases. about  78% of this mixture is nitrogen and  about 21% is oxygen.
• Carbon dioxide,  argon, methane, ozone and water vapor is also present in  very small  quantities in the air.

Hence, we conclude that,

smoke, dust, sulfur dioxide, and nitrogen dioxide are major sources of pollution of air.

Answer 2

Oxides of sulphur and nitrogen are the gaseous air pollutants while smoke and dust are particulate air pollutants.

Low concentrations of sulphur dioxide can cause respiratory diseases like asthma, bronchitis, emphysema. It can also cause irritation to the eyes.

Nitrogen dioxide can also cause acute respiratory disease in children. It is harmful to various textile fibres and metals.

The correct answer will be option c.