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Day 56 – Q 4. How is air quality measured? Discuss the parameters and indicators of Air Quality Index.

4. How is air quality measured? Discuss the parameters and indicators of Air Quality Index.

वायु की गुणवत्ता कैसे मापी जाती है? वायु गुणवत्ता सूचकांक के मापदंडों और संकेतकों पर चर्चा करें।


Air pollution levels in most of the urban areas have been a matter of serious concern. It is the right of the people to know the quality of air they breathe. However, the data generated through National Ambient Air Monitoring Network are reported in the form that may not be easily understood by a common person.


In view of this, CPCB took initiative for developing a national Air Quality Index (AQI) for Indian cities. AQI is a tool to disseminate information on air quality in qualitative terms (e.g. good, satisfactory, poor) as well as its associated likely health impacts. The formulation of the index was an initiative under Swachh Bharat Mission (Cleanliness Mission), based on the recommendations of IIT Kanpur and the Expert Group formed in this regard.

In India, National Air Quality Index (AQI) disseminates information on air quality in an easily understandable form for the general public. The measurement of air quality is based on eight pollutants, namely,

  • Particulate Matter (size less than 10 µm) or (PM10),  
  • Particulate Matter (size less than 2.5 µm) or (PM2.5),
  • Nitrogen Dioxide (NO2),
  • Sulphur Dioxide (SO2),
  • Carbon Monoxide (CO),
  • Ozone (O3),
  • Ammonia (NH3), and
  • Lead (Pb).

The index will be based on real time monitoring, and the health risks will be easily identified through a colour coded system. The risks will be signified through six levels – good, satisfactory, moderately polluted, poor, very poor, and severe.

Various ways to measure Air Quality:

  • Ground monitoring stations: continuous ambient air quality monitoring (CAAQM) stations collect data of 8 pollutants. Example: SAFAR (System of Air Quality and Weather Forecasting) in cities like Delhi.
  • Use of satellite data for air pollution monitoring. It helps to monitor pollution even in areas where ground-based network does not exist.


Given air pollution issues in the country, Government has launched National Clean Air Programme (NCAP) A time bound national level strategy for pan India implementation to tackle the increasing air pollution problem across the country in a comprehensive manner.

Best answer: Arvind Senta

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