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People of Color Are Disproportionately Hurt by Air Pollution

New York and Philadelphia top the list of urban areas with great gaps in pollution exposure between whites and non-whites.

In America, your race affects everything from your job to your commute to your brush-ups with the police. Why should it be any different with the amount of nasty air pollution you inhale?

Of course it isn't different, as shown by an eye-opening new study from the University of Minnesota. By overlaying Census data with a recent map of air pollution, the researchers discovered that in most places in the country, lower-income non-white people breathe more airborne foulness than higher-income whites. On average, non-white people inhale 38 percent higher levels of air pollution than whites, they say. If non-white people were brought down to the levels of pollution enjoyed by whites, it would prevent 7,000 deaths from heart disease in their communities each year.

Income also plays a role in pollution exposure, but not as much as you might think. "Both race and income matter, but race matters more than income," says Julian Marshall, a professor of environmental engineering at the University of Minnesota. "And that's a really important point, because when you start talking about differences by race people say, 'Oh, that's just income.'"

The discrepancy is so great that even high-earning non-whites are sucking in relatively larger quantities of pollution. For a clear illustration of that, take a look at this graph showing (at top left) pollution/income differences for large urban areas. Notice how low-income whites are exposed to less pollution than even the highest-income blacks, Asians, and Hispanics:

"Even considering high-income individuals only, the fact that you still see environmental injustice is a little surprising to me," says Marshall. As to why this is occurring, that's still a subject for further investigation; Marshall notes that one theory is that more non-whites tend to live in pollution-rich downtown areas and near freeways.

The specific pollutant that the researchers investigated is nitrogen dioxide, whose man-made sources include automobile engines and power plants. People who breathe more NO2 are at greater risk of a horde of ailments, from asthma to heart and lung disease to low birth weights. The researchers got a bead on how much NO2 is floating over America using satellite and land-use data from this study, which also inspired this interactive map of pollution levels. Look at how NO2 hovers over major metropolitan regions:

They also built their own maps of the America's pollution landscape, such as this one showing the "difference in population-weighted mean NO2 concentrations (ppb) between lower-income nonwhites and higher-income whites for U.S. cities." By their measurements the urban areas with the greatest gaps in pollution exposure between whites and nonwhites are New York-Newark, Philadelphia, and Bridgeport-Stamford, Connecticut, respectively:



And here's their list of the spots with the highest pollution disparity between whites and nonwhites (note that "urban areas" relates to a Census definition that can include parts of various neighboring states):

  • New York--Newark; NY--NJ--CT
  • Philadelphia; PA--NJ--DE--MD
  • Bridgeport--Stamford; CT--NY
  • Boston; MA--NH--RI
  • Providence; RI--MA
  • Detroit; MI
  • Los Angeles--Long Beach--Santa Ana; CA
  • New Haven; CT
  • Worcester; MA--CT
  • Springfield; MA--CT
  • Rochester; NY
  • Chicago; IL--IN
  • Birmingham; AL
  • Hartford; CT
  • Milwaukee; WI

Top image: Venturelli Luca /

About the Author

  • John Metcalfe
    John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.