AQI Report 2023- Delhi's Air Quality continues to remain 'Very Poor'

The Air Quality Index (AQI) in the national capital Delhi stood at 336 on November 1.  According to SAFAR-India, it continues to remain in the 'very poor' category.  The air quality index (AQI) is projected to remain in the ‘Very poor' category until November 3. The AQI is likely to remain in that range for the next six days. According to the Commission for Air Quality Management, starting November 1, only electric, CNG, and BS VI-compliant diesel buses would be permitted between Delhi and towns in the National Capital Region.

What is the National Air Quality Index?

• An Air Quality Index (AQI) is data used by government agencies to assess and report on air pollution levels. `Description' to help the average person estimate the air quality in his or her neighborhood.
• The AQI report assesses the density of various pollutants in the air (such as PM2.5, PM10, nitrogen dioxide, ozone, and so on) at various monitoring sites.
• The Central Pollution Control Board (CPCB) created it in collaboration with IIT-Kanpur and other experts. 
• It is measured in micrograms per cubic meter.
• The AQI is intended to inform people about how local air quality affects their health. 

Which Pollutants are Measured by AQI?

• The polluted atmosphere contains eight contaminants, each of which is assigned a weight based on a formula.  
• Particulate matter PM 10, PM2.5, Ozone (O3), Sulphur dioxide (SO2), Nitrogen dioxide (NO2), Carbon monoxide (CO), Lead (Pb), and ammonia (NH3) are the principal pollutants used to calculate an AQI of an area.

Calculation of the National Air Quality Index

• The National Air Quality Index in India is calculated using a 500-point scale.
• A score of between 0 and 50 is regarded as satisfactory in this system. 
• A rating in the range of 301 to 500 is considered risky. 
• These raw values are transformed into an AQI value for each contaminant separately.  

Categories of Air Quality 

• The National Air Quality Index divides air quality into six categories. 
• These are: Good, Satisfactory, Moderately Polluted, Poor, Very Poor, and Severe.

• The details of these six categories of AQI and its specific health consequences are given in the following table:

What are NAAQ standards?

• The Air (Prevention and Control of Pollution) Act gives the Central Pollution Control Board (CPCB) the authority to set air quality standards.
• As a result, the CPCB notified the current National Ambient Air Quality Standards in November 2009.
• Previously, India established air quality standards in 1994, which were then amended in 1998.
• The 2009 regulations reduced the maximum allowable limits for pollutants even further and made the requirements uniform across the country.

System of Air Quality and Weather Forecasting And Research (SAFAR)

• The System of Air Quality and Weather Forecasting And Research (SAFAR) is a national initiative to measure the air quality of a metropolitan city.
• Invented by - Ministry of Earth Sciences (MoES) 
• SAFAR is an essential component of India's first operational Air Quality Early Warning System in Delhi.
• It was created by the Indian Institute of Tropical Meteorology (IITM), Pune, India Meteorological Department (IMD), and National Centre for Medium Range Weather Forecasting (NCMRWF).
• SAFAR has been designated as a prototype activity by the World Meteorological Organisation because of the high quality control and standards maintained in its implementation.