Why in news?

The national capital breathed the cleanest post-Deepavali air in eight years, according to Central Pollution Control Board (CPCB)

Highlights:

• Though violations of the ban imposed on bursting crackers were reported leading to a spike in PM2.5 levels (particulate matter 2.5), the air quality improved with time due to favourable meteorological conditions.
• 5 are fine inhalable particles which can get into the bloodstream through the lungs leading to a number of respiratory illnesses

What is National Air Quality Index?

• NAQI is tool that uses numbers to simplify air quality data by classifying pollution levels into 6 categories—good, satisfactory, moderate, poor, very poor and severe—and denotes a colour codeon the basis of how harmful the pollution in a specific area is.
• Each of the pollutants—5, PM10, NO2, CO and Ozone are assigned an air quality index (AQI) and thereafter an overall AQI is given daily indicating the value of the worst pollutant value for that area.
• The AQI will consider eight pollutants (PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb) for which short-term (up to 24-hourly averaging period) National Ambient Air Quality Standards are prescribed.
• This index makes it easier for people to know how bad the pollution in their area is and which places they should avoid on that day. It is certain that awareness will go up with availability of a monitoring tool like this.