How Clean (or Dirty) Is Our Air?

During the spring, buried in the thickets of the debate over congestion pricing, was a great nugget in Mayor Michael Bloomberg’s PlaNYC 2030. Deep in the document was a promise: if PlaNYC 2030 was implemented, New York City would become the “cleanest big city in America.”

That got me thinking.

How clean is the air in New York City?

The short answer is that the nation’s air is cleaner than it’s been in decades, and so is New York’s. But New York City air is still polluted enough to send thousands of people to emergency rooms every summer and to send some of those people to early graves every year.

The longer answer is more complicated, and it goes like this:

Since 1970, the U.S. Environmental Protection Agencyhas set standards for the maximum amount of air pollution that is safe to breathe. In a city like New York, ozone (a principal ingredient of smog) and particulate matter (or soot) are the key pollutants—and the city has never met EPA’s standards for either pollutant. In each case, we are in the second-worst category (Los Angeles tops the "most polluted list" for both smog and soot). By this measure, the city seems to be in pretty bad pollution shape—especially because many environmental groups think that the current EPA standards are too weak.

Soot particles are the biggest pollution concern. A decade ago, the Natural Resources Defense Council (where I worked then, and now) estimated that 64,000 Americans died prematurely every year at then-current levels of particulate air pollution. More than 4,000 people of those premature deaths were in the New York metropolitan region.

In New York, diesel engines have long been at the heart of our local soot problem. When walking up Madison Avenue, most of the soot we breathe comes from a relatively small number of diesel engines—buses, trucks, and construction equipment. In more residential neighborhoods, home heating oil is diesel’s close—and even dirtier—cousin.