Last week, a World Health Organization (WHO) report on air pollution said that of the 20 most polluted cities in the world, the worst 14 are in India, and that these cities have become death traps because of the very high level of PM2.5 (particulate matter less than 2.5 micron size) in their air.

This latest and updated urban air quality database for 2016 includes Kanpur, Faridabad, Varanasi, Gaya, Patna, Delhi, Lucknow, Agra, Muzaffarpur, Srinagar, Gurgaon, Jaipur, Patiala, and Jodhpur. The list reveals several facts: one, Delhi has improved from number four to six but, as the Centre for Science and Environment correctly points out, the megacity’s better score is not because it has cleaned up its air but due to the fact that other Indian cities have become more polluted. In fact, Delhi’s PM2.5 levels have deteriorated since 2015.

Second, more Indian cities are now in the worst-20 list than Chinese ones, a change from the 2013 report. The Indian scenario could actually be worse: of the 5,000-odd cities and towns in the country, monitoring is carried out in only 307 . Who knows what a survey of the remaining may hold.

Third, the cities on the WHO list are all from north India. Is the peninsula better off because of the highly-humid South Indian environment or are these states doing something different (or differently)? The Indian bureaucracy is not known to learn from best practices, but it must try to see if the south is on a different trajectory from the north and why. Visakhapatnam, for example, which was classified as “critically-polluted” about eight years ago, has now got rid of that dubious tag.

What needs to be done to clean India’s air doesn’t need repetition. Each city has its own set of problems that need to be tackled at a local level; this can be aligned to a comprehensive national plan. But while we discuss the solutions, what needs to be talked about much more widely is not just the devastating effects of air pollution on people’s health (air pollution is the number one carcinogen, WHO has said) but also its wider ramifications.

For example, researchers at the London School of Economics have found that there is a link between air pollution and rising crimes in a city. Air pollution, as the WHO report says, is also deepening inequality since more than 90% of air pollution-related deaths occur in low- and middle-income countries, mainly in Asia and Africa, followed by low- and middle-income countries of the eastern Mediterranean region, Europe and the Americas.

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