At last India tops the charts. Six of our cities have made it to the World’s Top 10 list, thirteen to the Top 20. We may be bored with our nation’s impressive ranking near the bottom of various socio-economic indicators, but this performance will move even the most die-hard cynic: when it comes to the quality of the air we breathe we lead, bar none. At the very bottom.

Consider a string of imposing facts: As per WHO’s air pollution database of 1,600 cities globally, our national capital is the world’s most polluted, by quite an impressive margin. A full one-third of the world’s 100 worst cities are Indian.

How much do we lead by? Well, with an average of 153 mg of suspended particulate matter per cubic metre of air, Delhi’s atmosphere is 8-20 times as polluted as that of other megacities with similar levels of vehicular intensity – New York (14 mg per cubic meter), London (16), and Bangkok (20). In fact, this is one social indicator where we trump all the usual suspects, from Somalia to Rwanda and Sierra Leone.

There was a time when China was a saving grace for us. Back in 2000, Beijing’s air was more polluted than Delhi’s. Today, Delhi is 2.5 times worse – at 153 mg versus 56. Over the past 13 years Delhi has deteriorated by 47% while Beijing has actually improved, by 40%. Mumbai (a “Shanghai in the making”) has slipped from being a lot better than its so-called role model, to 25% worse. The rest of urban India follows a similar script.

Fair enough, but does it really matter? With such pressing problems as unemployment and hunger, poverty and illiteracy, isn’t an issue like air pollution a bit distant… even esoteric? Well, think again.

Air pollution is today estimated as the fifth largest killer in urban India, ahead of such hazards as tobacco smoking, high blood pressure and poor nutrition. It is responsible for a cut in life expectancy by 3.2 years for 660 million Indians (Delhi’s residents can bid goodbye to five years of their life).

40% of Delhi’s children fail the lung function test; our other metros follow closely with Bangalore at 36%, Kolkata at 35% and Mumbai at 27%. Over half of Delhi’s students suffer from Respiratory Disorder Syndrome. The quality of air we breathe is seen as the primary cause of such disorders.

The sources for the above findings are varied and weighty: WHO’s Air Pollution Database 2014; Study by Environmental Economists from Harvard, Yale and Columbia, Feb 2015; World Allergy Organization Journal published in 2013. The world’s environmental and health experts are totally aligned on the view that the menace of air pollution in urban India needs tackling on a war footing.

However a succession of Indian governments don’t quite seem to agree. The problem has been steadily on the rise from 2010, when de-regulation and a subsequent soaring of petrol prices led to a massive surge in the sale of diesel cars. However, despite a steadily rising crescendo of pleas by activists the government of the time paid no heed.

Amongst the many catchy slogans of the current government, there is none addressing this pressing problem. Even the Swachh Bharat abhiyaan is totally silent on air pollution. With toxicity levels going through the roof this winter, Indian media began to raise the issue as strongly as it could. Yet the latest budget did not mention the subject even in passing. The Environment Minister recently responded to the building crescendo as a ‘conspiracy’, till a storm of protest led to his withdrawing the statement.

What could the government do to fix the problem, if it was not in denial?

The biggest contributor to the surge in air pollution over the past few years is without doubt, the surge in the number of diesel vehicles. The soaring differential in the price of petrol and diesel (which peaked at Rs 33 per liter in 2013) led to the share of diesel cars moving from 15% of all new cars to 60%.

One diesel car using Euro 4 diesel – the fuel currently distributed in our metros – emits as much deadly particulate matter as 7 petrol cars. More than anything else, the government needs to fix the unchecked growth and emission levels of diesel-run vehicles.

To begin with we should mandate Euro 5 emission standards for all new diesel cars. Amongst other things, this requires the installing of a high-tech filter that cuts particulate matter emissions by 85 – 98%. The fuel supplied should similarly move to Euro 5 standards that limit sulfur to one-fifth of today’s levels. Currently, the government plans to implement Euro 5 by 2020. This is too late. Experts have argued that with a degree of will, Euro 5 can easily be phased in by 2018.

Meanwhile, we need to further reduce the price differential between petrol and diesel by equating tax levels on both (currently petrol is taxed at 50% and diesel at 30%). Since diesel cars are more expensive, this will automatically encourage most new car buyers to purchase petrol vehicles.

Experts have suggested a whole slew of other practical and fairly easy-to-adopt measures, too numerous to elaborate in this limited space.

All we need is a modicum of resolve.