Nationally, Air Pollution Has Fallen in Recent Decades. But Disparities Between Communities Persist.

New research from two UVA professors sheds light on environmental inequalities.

Air pollution can have serious consequences for a person’s quality of life. Inhaling high concentrations of “fine particulate matter,” or particles approximately 40 times smaller than a grain of sand, has been linked to cancer, heart disease, and even death Jonathan Colmer told an online audience last week.

Thankfully, fine particulate matter air pollution in the United States has dropped dramatically over the last few decades—by a full 70%, in fact. But new findings from Colmer, who teaches at the University of Virginia’s Department of Economics, and Batten’s Jay Shimshack reveal that we still have cause for concern. During the latest edition of Batten Expert Chats, the two professors discussed their research and its implications. 

Colmer and Shimshack were able to paint “an incredibly detailed picture” of air pollution in the U.S. by gathering data from 8.6 million locations for every year between 1981 and 2016. While air pollution has undeniably decreased overall, “relative disparities” have remained “remarkably persistent,” Shimshack said. As an example, he offered a sobering statistic: 94% of the areas that were among the most polluted in 1981 were still ranked among the most polluted in 2016.  

“But it's not just the most and the least polluted areas,” he said. “The general pattern of persistence holds at essentially every single point.” It also holds true across states, within states, and regardless of whether the location is urban or rural, he added.

Still, generally, “pollution has fallen,” Shimshack said. “Shouldn’t we just accept the win?” 

The answer, in their view, is not necessarily. “Fairness, equity, and justice are inherently comparative,” he said, “and our results suggest that from an air pollution perspective, who is disadvantaged and who is advantaged has remained remarkably constant through time.” 

Socioeconomically disadvantaged communities are far more likely to have higher levels of pollution at any point since 1981, Shimshack explained. In fact, relative disparities in pollution levels between more and less privileged areas may actually be getting larger: While richer, whiter communities have become relatively less polluted over the last few decades, the same is not true in disadvantaged communities. 

“Someone living in one of the most polluted neighborhoods in the United States today—which are disproportionately home to Hispanic people, lower income people, and other minority groups—is exposed to the same level of fine particulate matter as the average American was in the early 1990s,” he said.

Why do such disparities exist? There are many plausible explanations. While it’s true that people choose where they live, it’s not necessarily that simple. “Evidence suggests that people of color may not have the same choices as white people. If you're only able to choose from a set of bad outcomes, then there are more fundamental constraints that need to be addressed.” said Colmer.

Additionally, constraints that companies face in making their own choices could play a role. “There's also a sense in which pollution chooses where it lives—firms are going to choose where to set up shop, and they do this based on costs, wages, and land prices in a given area,” Colmer explained. Political considerations should be taken into account as well. “To some degree the louder your voice, the more of a say you have in these decisions,” he added. “There is a concern that disenfranchised communities may be less likely to have a voice.”

Still, all of these explanations remain tentative at the moment. The two professors hesitated to make specific policy recommendations, but emphasized the need for better dissemination of information on the issue. They are currently developing the Environmental Inequality Atlas, an interactive website where policymakers, journalists, NGOs, researchers, and the general public can visualize, download, and engage with neighborhood level measures of environmental risk.

In response to a question about whether local governments could play a role in addressing the disparities, Colmer noted the importance of a coordinated effort between various levels of government. But Shimshack said he believes that first and foremost the problem should be addressed at a higher level.

“A signature issue of federal and state environmental policies is that all people should have the same access to environmental protection,” he said. “We’re falling short.”