In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? 1. Carbon dioxide 2. Carbon monoxide 3. Nitrogen dioxide 4. Sulfur dioxide 5. Methane Select the correct answer using the code given below.
- (a) 1, 2 and 3 only
- (b) 2, 3 and 4 only ✓ UPSC's answer
- (c) 1, 4 and 5 only
- (d) 1, 2, 3, 4 and 5
Why the answer is (b)
• India's National Air Quality Index (2014) is computed from eight pollutants: PM10, PM2.5, nitrogen dioxide (3), sulphur dioxide (4), carbon monoxide (2), ozone, ammonia and lead.
• Carbon dioxide (1) and methane (5) are greenhouse gases, not local air-pollutants, and are not part of the AQI.
• Hence 2, 3 and 4 only, option (b).
Why the other options are wrong
- (a) 1, 2 and 3 only
- CO2 is not an AQI pollutant; SO2 is.
- (c) 1, 4 and 5 only
- CO2 and methane are not AQI pollutants.
- (d) 1, 2, 3, 4 and 5
- CO2 and methane are excluded from AQI.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.