Why we need a new lens to clear the air

Science may have become our only crutch against bad air, but it is time we invented a new politics of space that privileges the walker and the cyclist

By Rakesh Kalshian
Published: Wednesday 06 December 2017
Illustration: Tarique Aziz
Illustration: Tarique Aziz Illustration: Tarique Aziz

November is here, and so is the familiar miasma that grips the city in a deadly embrace every winter. Equally banal is the tableau of events that this annual spectre triggers—outrage followed by much hand-wringing among the public and media, passing-the-buck among politicians, and, finally, as the danger level crosses the red mark, a crackdown by the courts. So schools are shut down, health advisories issued, construction works grounded, thermal power plants turned off, and thousands of commercial trucks halted at the city limits. Meanwhile, makers of masks and air purifiers are making a killing.

This time, though, there was some respite as the apex court, in a controversial juggling act, banned sale, but not bursting, of firecrackers 10 days before and after Diwali. Some people burst crackers regardless. While the pollution levels shot up to severe levels over the following fortnight, the general feeling is that were it not for the ban, the air would have been much fouler.

At any rate, the contribution of firecrackers to Delhi’s pollution budget is, to mutate an adage, a mere particle in the atmosphere, especially as it comes only once a year. The trouble is it becomes complicit in an annual, even if accidental, conspiracy of whammies, such as dipping mercury, lethargic winds, stubble burning, and dust-laden winds blowing in from the deserts of west Asia, all of which, in concert with history-sheeters like vehicular exhaust, road dust, and smoke from power plants, effectively turn Delhi into a deadly gas chamber, sending PM2.5 levels soaring to 6-13 times higher than what is considered kosher.

To be sure, this is suicidal. According to the Lancet Commission on Pollution and Health, outdoor air pollution (mainly PM2.5—tiny particles 30 times smaller than the breadth of a human hair that can penetrate the deepest recesses of our lungs) kills about 4.5 million people every year across the world. Half of these live in China and India. More worrisome, as each person’s body reacts differently to each individual pollutant or their cocktail, scientists are reluctant to set any safe threshold. Any threshold is more a matter of economics than of health—in the EU it’s 25 micrograms per cubic metre, in US 12, and in India 60. Besides, scientists beware us that air pollution could trigger heart attacks, cancer, Alzheimer’s, and, most disturbingly, meddle with the vulnerable bodies of kids.

And yet, surprisingly, these frightening statistics haven’t triggered mass public protests. Ironically, while it hurts the poor the most, it is a small subset of the privileged that’s crying foul. The only reasonable explanation seems to be that people are not dropping dead like flies—contrast it with Delhi government’s feverish public campaign against the dengue outbreak. It’s a silent killer that gnaws away at your vitals, so most of us don’t even notice it till we are surprised by a heart attack or cancer. Messier still, it is just one of many suspects—pesticides, radiation, pathogens, faulty diet, or stress.

The origins of air pollution are as perplexing as its impacts are insidious. While we have a broad idea about what makes it foul, there is still some controversy over how different pollutants interact with one another under the influence of a capricious weather. Consider, for instance, the recent claim by government scientists that wind-borne dust from West Asia contributed 40 per cent of PM2.5 in the second week of November.

The deceptive and amorphous nature of the beast perhaps explains the political class’ apathy. With politicians looking forever askance, it leaves us, for better or worse, at the mercy of science, for only scientists have the expertise to judge air as good, bad, or ugly, and suggest ways of making it progressively less foul. The central government’s recent decision to introduce Euro VI fuel across the country by 2020 underscores this paradigm.

We wouldn’t have looked so stupid and helpless if we had the gumption to heed the lessons of the Capital’s first air pollution crisis in the 1990s, when the air was thick with vile poisons. Even then, the government was as apathetic and sceptical as people were indifferent. It took an uncanny rapport between a solicitous Supreme Court and a pro-active clean air campaign spearheaded by the Centre for Science and Environment’s (CSE) Anil Agarwal to not only replace all but private diesel vehicles with CNG-run alternatives, but also phase out antiquated engines and dirty fuel. Even though the science of air pollution was weak at the time, the Court invoked the precautionary principle to push the reforms.

The campaign led to palpably cleaner air. All the government needed to do now was put in place a cheap and efficient public transport system as well as a plan to progressively improve engine and fuel quality. However, as clean air activists soon realised, cleaner fuels were a mixed blessing. For instance, while switching to unleaded petrol took care of lead pollution, it spiked the levels of benzene, a known carcinogen. Likewise, even as low-sulphur diesel and the new diesel engines reduced PM10 levels, they emitted more NOx and, more dangerously, PM2.5 and even finer particles. It’s a trade off that works only if the number of vehicles is kept in check.

However, the early gains were allowed to go up in smoke as vehicle numbers zoomed exponentially, eventually crowning Delhi as the world’s most polluted city.

In the current discourse on air pollution, PM2.5 is projected as the archenemy—other villains like NOx, SOx, benzene have been relegated to cameo roles at best. However, as researchers Jos Lelieveld and Ulrich Pöschl at Germany’s Max Planck Institute for Chemistry argue in a recent Nature article, we need more science to clear the air not only about the nature of these air-borne micro-villains but also about the imprint they leave on our bodies. Among the many unsorted things, the causal link between emission levels and health impact is still fuzzy—for example, halving of SO2 levels in eastern China has had little impact on the number of deaths.

For some, this might sound like a self-preservation spiel for scientists who, one might dare say, are partly responsible for the toxic pea soup we find ourselves in. Besides, science of complex systems, like the human-environment complex, is itself undergoing a crisis following revelations that majority of research cannot be reproduced. Be that as it may, given the nature of our political economy, foul air is here to stay, leaving us with little choice but to trust science to keep most of us safe.

Unless, of course, just as Delhi got rid of much of its toxic air by leapfrogging to CNG in 2001, we could leapfrog again by switching to electric vehicles in the next two decades. France and the UK have already announced they are going to do it, and so has the Indian government, even if a little lukewarmly.

Electric vehicles might be the elusive knife that may cut the Gordian knot of air pollution. But, surely, that doesn’t give us the license to be motorists forever—in the long run what will likely work is hitching disruptive technologies to a politically transformative manifesto that puts the walker and the cyclist before the motorist.

Time travel is a monthly section which explores the tangled web of modern ideas about science and environment across space and time.

(This article was first published in the 1-15 December issue of Down To Earth).

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