Question

Which of the following is not considered as air pollutant?

• A. Smog
• B. Sulphur Dioxide
• C. Hydrocarbon
• D. Oxygen

Hint:

Essential atmospheric gases like oxygen are not pollutants, whereas toxic gases and smog are major air pollutants.

Answer 1

The Correct Option is D

Concept: Air pollutants are harmful substances present in the atmosphere that adversely affect human health, environment, and living organisms. Common air pollutants include:
• Smog
• Sulphur dioxide (\(SO_2\))
• Hydrocarbons
• Carbon monoxide
• Nitrogen oxides Oxygen is a natural and essential component of air required for respiration and life processes.

Step 1: Analyze option A.
Smog is a harmful air pollutant formed by smoke and fog.
Hence, option A is incorrect.

Step 2: Analyze option B.
Sulphur dioxide is a toxic gas responsible for respiratory problems and acid rain.
Hence, option B is incorrect.

Step 3: Analyze option C.
Hydrocarbons contribute to air pollution and photochemical smog formation.
Hence, option C is incorrect.

Step 4: Analyze option D.
Oxygen is an essential gas required for life and is not considered an air pollutant.
Hence, option D is correct. Therefore, the correct answer is: \[ \boxed{(D)\ \text{Oxygen}} \]