Consider the word “pollution.” What comes to mind? Perhaps constellations obscured by thick smog, perhaps the bright-red skyline of some industrial city by night, perhaps factories expelling billows of smoke. Perhaps even specific cities as Beijing and Shanghai, places notorious for having extreme amounts of pollution, to the discomfort of residents and travelers.
What maybe does not come to mind is New Delhi: the city in India with one of the worst pollution problems in the world.
The standard test of measuring pollution levels worldwide is called PM2.5. “PM” in the acronym refers to the levels of particulate matter in the atmosphere, and “2.5” refers to the size of the particulate matter: 2.5 micrometers in diameter or smaller. This is a very small size — small enough to penetrate deep into the human lungs, to make its way through the lungs and eventually the bloodstream.
The size of these particles is large in many ways. It large enough to be the cause of 1.5 million deaths in India per year — one-sixth of the total number of deaths. The air pollution has caused rates of asthma in Delhi to skyrocket. It has also contributed to chronic and acute heart disease.
Delhi has long known about its pollution problem, but only recently has it come up in the news and press. Articles in international news outlets record increases in asthma hospitalizations, as well as other respiratory illnesses. Scientists in the United States and abroad conduct studies quantifying what effect an increase in pollution might have on a human lifespan. And most notably, embassies in Delhi itself buy 1600 air filters to protect their employees and future visitors, including heads of state.
All this press coverage has made Indian residents more acutely aware than ever of their pollution problem. And how bad is it?
PM2.5 levels in Washington, D.C. average 15 micrograms per cubic meter. PM2.5 levels in Beijing average 95 micrograms per cubic meter, over 6 times higher than in Washington.
PM2.5 levels in Delhi, however, are even greater. They average a whopping 226 micrograms per cubic meter. It is enough to make residents note the nasal discharge that accumulates every day and disappears when they go out of the country. It is enough to finally ring the alarm on the worst-polluted city in the world, in a country with nine out of the eleven most polluted cities in the world.
Delhi’s pollution problem is especially troubling in that it is so hard to fix. The industrializing country has promised already to double coal usage in the upcoming five years.
Furthermore, a great amount of Indian automobiles run on diesel, due to government-subsidized fuel. The diesel engines cannot install filters because the fuel itself contains too much sulfur. There is no easy way to the decrease the number of cars on the road and thus the amount of pollution in the air.
Authorities in India and America have begun to note Delhi’s pollution problem. Though future plans are still being devised, the quantification of pollution levels has helped define the scope of the issue.