A breath of fresh air, it’s said, always makes one feel better; but when it comes to India, it can be dangerous. A World Health Organization (WHO) study of 1,600 cities finds that New Delhi has the world’s dirtiest air, with an annual average of 153 micrograms of small particulates —known as PM2.5—per cubic metre. These fine particles are linked to chronic bronchitis, lung cancer and even heart disease, as it easily enters our blood stream. The report also states that among the world’s 20 dirtiest cities, 13 are in India—a claim that India rejected. But the first step to any solution is to know the extent of the problem. It is towards this end that Prime Minister Narendra Modi launched the National Air Quality Index (AQI).
The AQI will act as an alert system, giving people details of air quality and information on its likely health implications. This information will be in real time. While the aim of India’s AQI is to cover 66 cities overall, as of now it covers 10—including Delhi, Agra, Kanpur, Lucknow, Varanasi, Faridabad, Ahmedabad, Chennai, Bangalore and Hyderabad.
Cities will be rated in a range from 0 to 500 depending on the quality of their air. A range from 0-50 is good, 51-100 satisfactory, 101-200 indicates moderate pollution, 201-300 poor, 301-400 very poor and anything above that means severe. While a rating of ‘good’ means that there is no impact on health due to air quality, a ‘severe’ rating means even healthy people may be affected. There is also a colour code for these pollution levels, with green, for example, representing the good 0-50 range.
The Central Pollution Control Board developed the index in consultation with IIT-Kanpur and other expert groups. With the launch of the AQI, India has joined countries such as the US, France, China and Mexico—all of which have similar systems in place.