An Air quality index also termed as AQI is a number used to inform people how polluted the air currently is or how polluted it is forecast to become. It is a parameter to signify the purity of air and its impact on human being. Normally there are six categories to define the quality of air i.e. Good, Satisfactory, Moderately polluted, Poor, Very Poor, and Severe. Majorly there are eight pollutants present in air namely as PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb which makes the air polluted.
The value of AQI ranges from 0-500. As the AQI level increases, air pollution level also increases. Lower the AQI value better the air quality. AQI level between 0-50 shows good air quality whereas AQI between 0-100 is supposed to be moderate .AQI greater than 100, starts impacting the public health. In India AQI is comparatively high with respect to other countries.