Question:medium

Which of the following are criteria pollutants under national ambient air quality standards?
A. PM\(_2.5\)
B. NO\(_x\)
C. Lead
D. Methane
E. Sulphur dioxide

Show Hint

The main six criteria pollutants focused on globally are CO, Pb, NO\(_2\), O\(_3\), PM (PM\(_2.5\)/PM\(_10\)), and SO\(_2\). Methane is usually discussed in the context of climate change, not direct air quality standards.
Updated On: Feb 18, 2026
  • A, B and D only
  • A, B and C only
  • A, C and E only
  • A, B, C and E only
Show Solution

The Correct Option is D

Solution and Explanation

Step 1: Define Criteria Pollutants. Criteria air pollutants are common air pollutants regulated by environmental agencies due to their harm to public health and the environment.

Step 2: List criteria pollutants in India (under NAAQS). India's National Ambient Air Quality Standards (NAAQS) regulate 12 pollutants: PM\(_10\), PM\(_2.5\) (A), Sulphur Dioxide (SO\(_2\)) (E), Nitrogen Dioxide (NO\(_2\)) (B, as part of NO\(_x\)), Ozone (O\(_3\)), Carbon Monoxide (CO), Lead (Pb) (C), Ammonia (NH\(_3\)), Benzene, Benzo(a)Pyrene, Arsenic, and Nickel.

Step 3: Evaluate the given options against the list. - A (PM\(_2.5\)), B (NO\(_x\)), C (Lead), and E (Sulphur dioxide) are on the list. - D (Methane) is a greenhouse gas but isn't regulated as a criteria pollutant for direct ambient air quality.

Conclusion: The correct combination is A, B, C, and E.

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