The MoEF, headed by Prakash Javadekar, is providing a comprehensive real-time Air Quality Index (AQI) data at 10 places in Delhi based on eight parameters. The new system was launched in April this year after a series of reports—mostly international—highlighted that Delhi is the most polluted city in the world. Some reports showed 13 Indian cities among the top 20 most polluted cities of the world.

In Delhi, AQI is collected at ITO, Mandir Marg, Anand Vihar, Shadipur, Civil Lines, IGI Airport, R K Puram, Punjabi Bagh, Dwarka and near Dilshad Garden. ITO and Anand Vihar, which witness heavy traffic throughout the day, record severe air pollution, while levels in other parts of the city range between satisfactory and moderate.

Javadekar said that traditionally, air quality status has been reported through voluminous data and it was important that information on it quality made available in simple linguistic terms that is easily understood by a layman. “The environment ministry has decided to provide free AQI data for comprehensive health of air. We are working with neighboring states to improve pollution levels in Delhi. A roadmap has been prepared, pollution levels will come down,” he said.

The index has categories with a colour scheme beginning with green and ending in dark red (as One Number-One Colour-One Description) for the common man to judge air quality. There are six AQI categories: good, satisfactory, moderately polluted, poor, very poor and severe. Based on the measured ambient concentrations, corresponding standards and likely health impact for each of these pollutants are measured.

An expert group comprising medical professionals, air quality experts, academia, advocacy groups and State Pollution Control Boards was constituted and a technical study was awarded to IIT Kanpur. They recommended an AQI scheme, which will be based on eight air pollutants: particulate matter (PM10, PM2.5), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), O3 (ozone), ammonia (NH3) and lead (Pb).