John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
New York and Philadelphia top the list of urban areas with great gaps in pollution exposure between whites and non-whites.
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