It is a number used to communicate to the public how polluted the air currently is or how polluted it is forecasted to become. As AQI increases, an increasingly large percentage of the population is likely to experience increasingly adverse health effects. Different countries have their own air quality indexes, corresponding to different national air quality standards. AQI is most commonly used by CPCB to describe ground-level ozone levels. The classifications of air quality are part of a 6 grade, colour coded taking into account 8 pollutant levels.
These pollutants are:
- Ground-level Ozone or O3
- Particulate Matter (soot and dust) – PM2.5 and PM10
- Carbon Monoxide or CO
- Sulphur Dioxide or SO2 and
- Nitrogen Dioxide or NO2 6. Ammonia or NH3
- Lead or PB