Hindustan Times A smoggy day in New Delhi, November 2012

The economic growth that many nations in Asia and increasingly Africa have experienced over the past couple of decades has transformed hundreds of millions of lives — almost entirely for the better. But there’s a byproduct to that growth, one that’s visible — or sometimes less than visible — in the smoggy, smelly skies above cities like Beijing, New Delhi and Jakarta. Thanks to new cars and power plants, air pollution is bad and getting worse in much of the world, and it’s taking a major toll on global health.

How big? According to a new analysis published in the Lancet, more than 3.2 million people suffered premature deaths from air pollution in 2010, the largest number on record. That’s up from 800,000 in 2000. And it’s a regional problem: 65% of those deaths occurred in Asia, where the air is choked by diesel soot from cars and trucks, as well as the smog from power plants and the dust from endless urban construction. In East Asia and China, 1.2 million people died, as well as another 712,000 in South Asia, including India. For the first time ever, air pollution is on the world’s top-10 list of killers, and it’s moving up the ranks faster than any other factor.

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David Pettit of the Natural Resources Defense Council explains why air pollution can be so deadly:

So how can air pollution be so damaging? It is the very finest soot — so small that it lodges deep within the lungs and from there enters the bloodstream — that contributes to most of the public-health toll of air pollution including mortality. Diesel soot, which is also a carcinogen, is a major problem because it is concentrated in cities along transportation corridors impacting densely populated areas. It is thought to contribute to half the premature deaths from air pollution in urban centers. For example, 1 in 6 people in the U.S. live near a diesel-pollution hot spot like a rail yard, port terminal or freeway.

We also know that air pollution may be linked to other nonlethal conditions, including autism. Fortunately in the U.S. and other developed nations, urban air is for the most part cleaner than it was 30 or 40 years ago, thanks to regulations and new technologies like the catalytic converters that reduce automobile emissions. Governments are also pushing to make air cleaner — see the White House’s move last week to further tighten soot standards. It’s not perfect, but we’ve had much more success dealing with air pollution than climate change.

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Will developing nations like China and India eventually catch up? Hopefully — though the problem may get worse before it gets better. The good news is that it doesn’t take a major technological leap to improve urban air. Switching from diesel fuel to unleaded helps, as do newer and cleaner cars that are less likely to spew pollutants. Power plants — even ones that burn fossil fuels like coal — can be fitted with pollution-control equipment that, at a price, will greatly reduce smog and other contaminants.

But the best solutions may involve urban design. In the Guardian, John Vidal notes that Delhi now has 200 cars per 1,000 people, far more than much richer Asian cities like Hong Kong and Singapore. Developing cities will almost certainly see an increase in car ownership as residents become wealthier — and that doesn’t have to mean lethal air pollution. (Even ultra-green European cities often have rates of car ownership at or above the level Delhi has now.) Higher incomes should also lead to tougher environmental regulations, which is exactly what happened in the West. We can only hope it happens before the death toll from bad air gets even higher.

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