Increasing Racial and Ethnic Disparities in Ambient Air Pollution-Attributable Morbidity and Mortality in the United States

Abstract

Background: Ambient nitrogen dioxide (${\mathrm{NO}}_2$) and fine particulate matter with aerodynamic diameter $\le 2.5\mu m$ (${\mathrm{PM}}_{2.5}$) threaten public health in the US, and systemic racism has led to modern-day disparities in the distribution and associated health impacts of these pollutants.

Objectives: Many studies on environmental injustices related to ambient air pollution focus only on disparities in pollutant concentrations or provide only an assessment of pollution or health disparities at a snapshot in time. In this study, we compare injustices in ${\mathrm{NO}}_2\text{-}$ and ${\mathrm{PM}}_{2.5}\text{-attributable}$ health burdens, considering ${\mathrm{NO}}_2\text{-attributable}$ health impacts across the entire US; document changing disparities in these health burdens over time (2010-2019); and evaluate how more stringent air quality standards would reduce disparities in health impacts associated with these pollutants.

Methods: Through a health impact assessment, we quantified census tract-level variations in health outcomes attributable to ${\mathrm{NO}}_2$ and ${\mathrm{PM}}_{2.5}$ using health impact functions that combine demographic data from the US Census Bureau; two spatially resolved pollutant datasets, which fuse satellite data with physical and statistical models; and epidemiologically derived relative risk estimates and incidence rates from the Global Burden of Disease study.

Results: Despite overall decreases in the public health damages associated with ${\mathrm{NO}}_2$ and ${\mathrm{PM}}_{2.5}$, racial and ethnic relative disparities in ${\mathrm{NO}}_2\text{-attributable}$ pediatric asthma and ${\mathrm{PM}}_{2.5}\text{-attributable}$ premature mortality have widened in the US during the last decade. Racial relative disparities in ${\mathrm{PM}}_{2.5}\text{-attributable}$ premature mortality and ${\mathrm{NO}}_2\text{-attributable}$ pediatric asthma have increased by 16% and 19%, respectively, between 2010 and 2019. Similarly, ethnic relative disparities in ${\mathrm{PM}}_{2.5}\text{-attributable}$ premature mortality have increased by 40% and ${\mathrm{NO}}_2\text{-attributable}$ pediatric asthma by 10%.

Discussion: Enacting and attaining more stringent air quality standards for both pollutants could preferentially benefit the most marginalized and minoritized communities by greatly reducing racial and ethnic relative disparities in pollution-attributable health burdens in the US. Our methods provide a semi-observational approach to track changes in disparities in air pollution and associated health burdens across the US. https://doi.org/10.1289/EHP11900.