UPSC Prelims 2016 Question:

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.

Explanation: 

• • The 'National Air Quality Index’ (AQI) was launched by the Ministry of Environment, Forests & Climate Change. It provides "One Number- One Colour-One Description" of air quality which enables the common man to judge the air quality in its vicinity.
  •  There are six AQI categories, namely Good, Satisfactory, Moderately-polluted, Poor, Very Poor, and Severe.  The AQI considers eight pollutants -

• Particulate Matter 10; PM10 

• Particulate Matter 2.5; PM2.5

• Nitrogen dioxide; NO2

• Sulfur dioxide; SO2, 

• Carbon monoxide; CO

• Ozone; O3

• Ammonia; NH3

• Lead; Pb 

For which short-term (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed. So, points 2, 3 and 4 are correct.

Therefore, option (2) is the correct answer.

Subject: Environment |Pollution