National Air Quality Index (AQI) was launched in 2014 by MoEFCC to gauge air quality in the country. It was promoted as ‘One Number- One Color-One Description’ for the common man to judge the air quality within his vicinity.
There are six AQI categories, namely Good, Satisfactory, Moderately polluted, Poor, Very Poor, and Severe. The AQI considers 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.
Based on the measured ambient concentrations, corresponding standards and likely health impact, a sub-index is calculated for each of these pollutants. The worst sub-index reflects overall AQI.
Likely health impacts for different AQI categories and pollutants have been also been suggested, with primary inputs from the medical expert members of the group.
