Which of the following gases is not considered as a polluting agent of air?
2016
Which of the following gases is not considered as a polluting agent of air?
- A.
SO₂
- B.
CO₂
- C.
CO
- D.
NO₂
Attempted by 109 students.
Show answer & explanation
Correct answer: B
Answer: Carbon dioxide (CO₂) is not classified as a conventional local air pollutant. CO₂ — A naturally occurring greenhouse gas required for photosynthesis. It contributes to global warming but is not directly toxic at typical ambient concentrations, so it is treated separately from local toxic air pollutants.