Delhi’s poor air quality has rightly made it the centre of media and government attention. However, the Indian government’s own air quality monitoring apparatus now shows the focus so far may have remained too narrowly on some pollutants and, as a result, only on some cities. >India’s Air Quality Index, launched by Prime Minister Narendra Modi in early April, presents >an AQI value for a given city based on the prominent pollutant in that city, calibrated for comparison. Six months of AQI values for 11 Indian cities show that Kanpur, Varanasi and Chennai have worse air quality than Delhi, on average. While Delhi and the rest of north India have higher particulate matter levels, cities such as Chennai find high concentrations of other toxic pollutants including sulphur dioxide and nitrogen dioxide. Dust, caused by a wide range of natural and man-made activities, can have a deeply damaging impact on the respiratory tract. But at the levels at which they are being experienced, gaseous pollutants have equally detrimental effects. The value of the AQI, one of the experts said, is in it being comparable across cities and across pollutants in terms of health impact. Some cities have been complacent over their low particulate matter levels. However, the new numbers show there is no room for complacency; other pollutants have been poisoning people.

The government has taken a great first step in setting up a >national Index and in making data for 11 cities, for now, public. Data for more cities and monitoring stations need to be brought online. The next step should be for policy-makers to actually look at this data; the government’s own website is clearly showing that a number of Indian cities are experiencing what should be health emergencies on a daily basis, going by their AQI levels. Local governments must clamp down on the specific pollutants that are pushing their respective cities into >the danger zone, whether it means moving polluting industries outside city limits or curbing the number of private vehicles by making available better public transport systems. They must also make it a habit to monitor pollution levels more closely. The Union government, meanwhile, must come out with an action plan for ‘severe’, ‘very poor’ and ‘poor’ air quality days; in Beijing, for instance, government vehicles are pulled off the roads, factories forced to limit production, schools shut down and citizens told to stay indoors on days when air pollution rises to an orange or red alert level. India needs similar clear instructions on what parents, teachers and commuters should do on poor air quality days. Else, all that they will be able to do is look at the index and worry for their health.