Aerial view of the Washington Monument and the White House, with city buildings in the background
Health risks from air pollution are uneven and inequitable in Washington, D.C., a new study finds. Credit: U.S. Air Force Tech. Sgt. Andy Dunaway
Source: GeoHealth

Levels of air pollution are increasing throughout many cities around the world. Previous studies have shown a strong association between the presence of fine particulate matter with a diameter of less than 2.5 micrometers (PM2.5) and health risks, including cardiovascular and respiratory diseases, lung cancer, and asthma. Although the Clean Air Act has improved air quality in the United States since its inception in 1970, its improvements have not been equitable—marginalized people are consistently exposed to higher air pollution levels and, by extension, greater health risks. To address these inequities, information about exposure levels and disease rates at the neighborhood scale are necessary.

In a new study, Castillo et al. home in on Washington, D.C., to determine the extent of the disparity in PM2.5-related cases of mortality and disease. The authors analyzed PM2.5 concentration data gathered from satellites as well as two data sets on disease rates—a small-scale estimation data set from the Centers for Disease Control and Prevention’s 500 Cities Project and another local administrative data set from the D.C. Department of Health. They used five neighborhood-level factors—education, unemployment, income, race and ethnicity, and life expectancy at birth—to analyze the differences in estimated PM2.5-related mortality and disease outcomes between D.C. subgroups.

Researchers found that although PM2.5-related health problems have decreased in Washington, D.C., over the past 20 years, these problems are uneven and inequitable across neighborhoods and subgroups. Of the 51 neighborhoods studied, the 10 with the highest PM2.5-related health risks had 10% lower education and employment rates, 10% more people living in poverty, and $61,000 lower median household income compared with their less at-risk counterparts. The 10 neighborhoods with the highest PM2.5-attributed mortality had 54% more Black residents. Generally, neighborhoods in D.C.’s southeast region were more at risk than those in the northwest—risk of chronic obstructive pulmonary disease, lung cancer, and stroke mortality was 5 times higher in southeast wards, and risk of asthma-related emergency department visits was 30 times higher than in northwest wards.

Castillo and colleagues say their study can provide important insight for mitigation strategies in Washington, D.C., and beyond. Fine-scale disease data should be taken into account during policymaking to lessen health inequities in cities, they say. (GeoHealth,, 2021)

—Alexandra K. Scammell (@alexkscammell), Associate Editor

Citation: Scammell, A. K. (2021), Air pollution poses inequitable health risks in Washington, D.C., Eos, 102, Published on 23 November 2021.
Text © 2021. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.