Disparities in Air Pollution Exposure in the United States by Race/Ethnicity and Income, 1990–2010

Abstract

Background: Few studies have investigated air pollution exposure disparities by race/ethnicity and income across criteria air pollutants, locations, or time. Objective: The objective of this study was to quantify exposure disparities by race/ethnicity and income throughout the contiguous United States for six criteria air pollutants, during the period 1990 to 2010. Methods: We quantified exposure disparities among racial/ethnic groups (non-Hispanic White, non-Hispanic Black, Hispanic (any race), non-Hispanic Asian) and by income for multiple spatial units (contiguous United States, states, urban vs. rural areas) and years (1990, 2000, 2010) for carbon monoxide (CO), nitrogen dioxide ( ), ozone ( ), particulate matter with aerodynamic diameter ( ; excluding year-1990), particulate matter with aerodynamic diameter ( ), and sulfur dioxide ( ). We used census data for demographic information and a national empirical model for ambient air pollution levels. Results: For all years and pollutants, the racial/ethnic group with the highest national average exposure was a racial/ethnic minority group. In 2010, the disparity between the racial/ethnic group with the highest vs. lowest national-average exposure was largest for [54% ( )], smallest for [3.6% ( )], and intermediate for the remaining pollutants (13%–19%). The disparities varied by U.S. state; for example, for in 2010, exposures were at least 5% higher than average in 63% of states for non-Hispanic Black populations; in 33% and 26% of states for Hispanic and for non-Hispanic Asian populations, respectively; and in no states for non-Hispanic White populations. Absolute exposure disparities were larger among racial/ethnic groups than among income categories (range among pollutants: between 1.1 and 21 times larger). Over the period studied, national absolute racial / ethnic exposure disparities declined by between 35% ( ; ) and 88% ( ; CO); relative disparities declined to between ( ; i.e., nearly zero change) and (CO; i.e., a reduction). Discussion: As air pollution concentrations declined during the period 1990 to 2010, absolute (and to a lesser extent, relative) racial/ethnic exposure disparities also declined. However, in 2010, racial/ethnic exposure disparities remained across income levels, in urban and rural areas, and in all states, for multiple pollutants. https://doi.org/10.1289/EHP8584

Ambient Air Pollution and Socioeconomic Status in China

“…A smaller body of literature documents disparities nationwide for the United States ( Bell and Ebisu 2012 ; Clark et al. 2014 , 2017 ; Liu et al. 2021 ; Miranda et al.…”

The One-Two-Three Punch: Exposure, Susceptibility, and Disease Burden among U.S. Populations of Color

“…Multiple studies have demonstrated that people of color in the United States are typically exposed to higher levels of air pollution than White Americans, regardless of income. 1 , 2 , 3 This persistent inequity appears to increase vulnerability to pollution-related disease among these groups. 4 The authors of a new paper in Environmental Health Perspectives explored whether health disparities might be reduced if federal regulators considered differences in the association between air pollution exposure and mortality across different racial/ethnic groups.…”

Invited Perspective: Moving from Characterizing to Addressing Racial/Ethnic Disparities in Air Pollution Exposure

“…Liu et al. ( 2021 ) built on this literature in a few important ways. They included all criteria air pollutants in a single analysis and looked at multiple years (1990, 2000, and 2010) across the entire contiguous United States.…”

“…In addition, as articulated by Liu et al. ( 2021 ), air pollution disparities analyses are generally dependent on publicly available census data, which creates limitations in moving beyond general racial/ethnic categories (e.g., the Hispanic category, which encompasses numerous countries of origin, racial identities, and nativity statuses). Census data also limit the ability to conduct truly intersectional analyses or to incorporate attributes, such as sexual orientation or gender identity, that are underrepresented in the environmental justice literature ( Collins et al 2017 ).…”

“…Liu et al. ( 2021 ) should be commended for their comprehensive, rigorous, and informative analyses. Now it is time to move beyond describing disparities and to start addressing them.…”