Air pollution, the leading environmental cause of death worldwide, reflects the stark racial inequalities of American life. In the United States, the problem is disproportionately caused by the white majority, but its consequences are suffered mainly by blacks and Hispanics.
That is the finding of a new study, about five years in the making, published Monday in the Proceedings of the National Academy of Sciences of the United States of America. The results illuminate the fault lines of the lethal environmental danger, which is inseparable from the threat of climate change and responsible for more deaths globally each year than automobile accidents.
The research confirms with new statistical certainty the determination that racial and ethnic minorities are acutely vulnerable to air pollution because of the neighborhoods in which they live. But it also introduces a largely unstudied element into the analysis, examining who is responsible for the pollutants inhaled disproportionately by blacks and Hispanics. The answer, according to a nationwide team of engineers and economists, is white people.
The researchers argue that white people are disproportionately to blame for the consumption of goods and services generating dangerous particles known as “fine particulate matter,” which gets lodged deep in the lungs, causing inflammation that triggers strokes and heart attacks, as well as cardiovascular and respiratory diseases. However, this segment of the population doesn’t endure an equivalent share of the consequences.
The study concludes that white people enjoy a so-called pollution advantage. They bear the burden of 17 percent less air pollution than is generated by their own consumption. Blacks and Hispanics, on the other hand, experience a “pollution burden.” They face 56 percent and 63 percent more exposure, respectively, than is caused by their consumption.
“That’s a pretty big difference,” the paper’s lead author, Christopher W. Tessum, a postdoctoral researcher focusing on civil and environmental engineering at the University of Washington, said in an interview with The Washington Post.
One of his co-authors, Julian D. Marshall, a professor of environmental engineering at the University of Washington, said the results sharpen the sense of injustice that comes from environmental degradation’s unequal impact.
“It seems even more unfair that some groups are more exposed to air pollution when one looks at who’s actually contributing to those unequal exposures,” he said.
The disparities persisted between 2003 and 2015, the time frame of the study, even as overall exposure declined during the same period by about 50 percent. The gap in contributions to pollution owed more to the level of consumption than to the types of goods and services consumed.
Income, which has previously been shown to matter less than race in exposure disparities, mattered crucially in discerning how much pollution a person causes because it tends to predict consumption, the authors observed. And differences in consumption, the data revealed, counted even more in determining the overall inequity than did differences in exposure.
The greatest disparity between the racial groups was in “commercial cooking,” Tessum said — in other words, going to restaurants.
The activity is just one example of personal consumption, which can mean anything from building a house to driving a car to buying food. Personal consumption is the leading cause of premature deaths from domestic emissions of air pollutants, the paper notes, ahead of demand for exported goods and pollution stemming from government expenditures.
The authors broke down acts of personal consumption by race to assess how emissions were driven differently by people self-identifying as black or African American, representing about 12 percent of the population; Hispanic or Latino, representing about 17 percent of the population; and non-Hispanic whites combined with all other groups, together representing about 70 percent of the population.
“The thing that’s causing the disparity is the different amounts of consumption,” Tessum said. “White people spend more money.”
Addressing exposure, the study found that black Americans were more exposed than whites to every type of emission, from road dust to construction. The same held true for Hispanics, with the exception of agriculture, coal electric utilities and residential wood combustion — emissions concentrated in parts of the country where Hispanics tend not to live, according to the authors.
The study does not offer solutions but rather “reveals a new lens for looking at this problem,” Tessum said. Still, it became apparent in the course of the research that declining exposure between 2003 and 2015 was a product of government regulation.
“That’s something that, as far as we can tell, has been working,” he said. “It might be beneficial.”
The Environmental Protection Agency, which is responsible for overseeing federal standards, would sustain a budget cut of 31 percent under the 2020 budget proposal unveiled this week by President Trump. Meanwhile, a handful of states are suing the Trump administration over its plans to reverse a determination reached under President Barack Obama that would have required the EPA to do more to contain air pollution at risk of traveling across state lines. So, too, Democrats, newly in control of the House, have put the administration on notice that they plan to scrutinize its approach to policing pollution standards.
Notoriously, Robert Phalen, a Trump appointee to an EPA advisory committee, said in 2012 that the air was “a little too clean for optimum health.”
The United Nations calls air pollution “the most important environmental health risk of our time.” But the risk is not distributed evenly across the globe, just as it is not borne equally in the United States. A report released last week by Greenpeace and the software company IQAir AirVisual found that the world’s most polluted cities are concentrated in India. In North America, Anderson, Calif., ranks as the second-most polluted city, after Mexicali, Mexico. The next U.S. city in the report, Medford, Ore., is seventh.
Tessum got the idea to study inequities in contributions to emissions from a question a number of years ago at a conference of the International Society for Environmental Epidemiology. He was presenting preliminary results of his efforts to track differences in exposure across a broad swath of the economy, after first looking narrowly at vehicles.
“Someone asked — and I never got a name — whether it would be possible to look at how different groups of people are also consuming differently,” he recalled.
The answer was yes, and the conclusion was that different groups were indeed consuming vastly differently.
“Do I find it surprising? The answer is yes and no,” Marshall, the University of Washington professor, said. “It’s not surprising if you consider how our society is set up. But this hasn’t been quantified before."
He said he hoped there would be benefits in quantifying the inequity, perhaps initiating a dialogue not just about health outcomes and the environment but also about race and government regulation.