Study Finds Exposure to Air Pollution Higher for People of Color Regardless of Region or Income

Published September 20, 2021

In the United States, people of color breathe more particulate air pollution on average, a finding that holds across income levels and regions of the US, according to a study by researchers at the EPA-funded Center for Air, Climate, and Energy Solutions. The findings expand a body of evidence showing that African Americans, Hispanics, Asians, and other people of color are disproportionately exposed to a regulated air pollutant called fine particulate matter (PM_2.5).

The findings, published in April 2021 in Science Advances, have serious public health implications–exposure to PM_2.5 can cause lung and heart problems, especially for those with chronic disease, younger people, older people, and other more vulnerable populations. 

The researchers conducted modeling and analyzed EPA data from the National Emissions Inventory for more than 5,000 emission source types for PM_2.5 such as industry, agriculture, light- and heavy-duty vehicles, construction, residential sources, and road dust to determine which source(s) were causing inequal exposure to PM_2.5 pollution by race-ethnicity.

They found racial-ethnic disparities for nearly all major emission categories. White people are exposed to lower than average concentrations from emission source types causing 60 percent of overall exposure, whereas people of color experience greater than average exposures from source types causing 75 percent of overall exposure. The disparity generally held across states and urban and rural areas and occurs for people at all income levels.

In other words, the study found that race appears to be an important factor for exposure in nearly all regions.

“Some assume that when there is a systematic racial-ethnic disparity, such as the one we see here, that the underlying cause is a difference in income,” says lead author Christopher Tessum of the University of Illinois. “Because the data shows that the racial disparities hold for all income levels, our study reinforces previous findings that race/ethnicity, independently of income, drives air pollution-exposure disparities.”

Tessum said the results have implications for how regulations might be designed to effectively address environmental injustice for people of color exposed to air pollution from multiple source types.

“We find that nearly all emission sectors cause disproportionate exposures for people of color on average,” said co-author Julian Marshall, a professor of civil and environmental engineering at the University of Washington. The authors noted in the paper that because of a legacy of housing policy and other factors, racial-ethnic exposure disparities continue to persist even with a decrease in the overall exposure. 

“The inequities we report are a result of systemic racism: Over time, people of color and pollution have been pushed together, not just in a few cases but for nearly all types of emissions,” said Marshall.

The study results also comes with caveats including uncertainty in the models and in inputs to the models and notes the potential benefit of additional analysis using local data and expertise. In addition, the study focuses on outdoor concentrations at locations of residence; disparities in associated health impacts would also reflect racial-ethnic variability in mobility, microenvironment, outdoor-to-indoor concentration relationships, dose-response, access to health care, and baseline mortality and morbidity rates.

EPA's goal is to provide an environment where all people enjoy the same degree of protection from environmental and health hazards and equal access to the decision-making process to maintain a healthy environment in which to live, learn, and work. To help achieve this, EPA researchers are focused on understanding the air quality concerns in overburdened communities and the health impacts of the residents. They are providing scientific expertise and tools to assist states, tribes, and communities to address environmental justice and equity issues, so that all people can breathe clean air and enjoy improved quality of life.

This research was funded by an EPA Science to Achieve Results grant: https://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract_id/10614

Reference:

Tessum, C. W., Paolella, D. A., Chambliss, S. E., Apte, J. S., Hill, J. D., & Marshall, J. D. (2021). PM2. 5 polluters disproportionately and systemically affect people of color in the United States. Science Advances, 7(18), eabf4491.