The Environmental Protection Agency’s air quality monitors are disproportionately positioned in whiter neighborhoods across the U.S., leaving communities of color less protected from dangerous pollutants such as particulate matter, ozone, nitrogen dioxide and lead, among others, new research shows.
The policies and actions the EPA takes to reduce pollution are developed based on the monitors’ measurements, and communities of color are generally more likely to be near major polluters. The findings raise questions about whether the agency has installed enough monitors, is placing them properly and whether its conclusions about air safety in some areas are accurate.
“It seems like an obvious problem, but we don’t see much about… how there is measurement error in the gold standard of data collection,” said Brenna Kelly, a doctoral candidate at the University of Utah and co-author of the study. “In this way we establish safety thresholds and determine who is susceptible to exposure to air pollution.”
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The researchers checked the position of nearly 8,000 EPA monitors across the country and compared their locations to census block data.
The study consistently showed lower average levels of monitors for particulate matter, ozone, nitrogen dioxide and lead among all non-white groups. The chemicals have been linked to a range of health effects, including asthma, chest pain, cardiovascular disease, neurotoxicity in developing children and cancer.
It found the greatest disparity in sulfur dioxide monitors in Native American and Pacific Islander groups. Sulfur dioxide is a common emission during natural gas and petroleum extraction, oil refining and metal processing. It can cause breathing difficulties and worsen other breathing problems.
The positions of the EPA monitors are determined by federal, state and local authorities, the study said, although Kelly said there was no clear process for determining where a monitor should be placed. Variables such as population density and concentration of polluters play a role in the decision.
However, the process “could become quite political,” Kelly added. Communities with more resources and political power may be able to influence the process, which may partly explain the inequality. The issue is also likely part of “institutionalized racism” in the decision-making process — marginalized groups tend to receive fewer resources, Kelly added.
The EPA’s monitors work by measuring a single point intended to be a representative sample of a larger region around it. The agency estimates broader regional air quality using a form of interpolation, but this approach can leave significant gaps. The spaces and gaps generally seem to be inhabited by communities of color.
Monitoring could be improved by using satellite images, the study notes. It can capture pollution across an entire region, but it also has limitations and would need to be deployed near the ground along with air monitors.
“That’s the big question: ‘How do we get better data?’” Kelly said. “The dream is that we will have insight into air pollution in every area at all times, how people move through their environment and how that changes what they are exposed to.”
