Question

Which of the following is not a pollutant unless present in excess?

• A. Sulphur dioxide
• B. Carbon dioxide
• C. Carbon monoxide
• D. Nitrogen dioxide

Answer 1

Answer: (B)

Carbon dioxide

Carbon dioxide can be either described as pollutant or not a pollutant depending on the source of emission. The carbon dioxide gas which is released as the exhausts and emissions from the industries causes pollution when in excess and are referred as a pollutant. The carbon dioxide which is released from the plants and animals as the end product of respiration is not considered as a pollutant.

Thus, the correct answer is option B.