People of color breathe more air pollution

Source: Jennifer Langston-Washington, Futurity, September 17, 2017

People of color are exposed to more pollution from cars, trucks, and power plants than whites, a new 10-year study shows. Researchers estimated exposure to outdoor concentrations of a transportation-related pollutant—nitrogen dioxide (NO2)— in both 2000 and 2010, based on neighborhoods where people live and found that disparities in NO2 exposure were larger by race and ethnicity than by income, age, or education. Further, that relative inequality persisted across the decade. While absolute differences in exposure to the air pollutant dropped noticeably during that time period for all populations, the relative difference—or the percent difference between pollution levels to which white people and people of color were exposed—narrowed only a little…..

…..If people of color had breathed the lower NO2 levels experienced by whites in 2010, it would have prevented an estimated 5,000 premature deaths from heart disease among the nonwhite group, researchers say…..

Changes in Transportation-Related Air Pollution Exposures by Race-Ethnicity and Socioeconomic Status: Outdoor Nitrogen Dioxide in the United States in 2000 and 2010
Source: Lara P. Clark, Dylan B. Millet, and Julian D. Marshall, Environmental Health Perspectives, Vol. 125 no. 9, September 2017

From the abstract:
Disparities in exposure to air pollution by race-ethnicity and by socioeconomic status have been documented in the United States, but the impacts of declining transportation-related air pollutant emissions on disparities in exposure have not been studied in detail.

This study was designed to estimate changes over time (2000 to 2010) in disparities in exposure to outdoor concentrations of a transportation-related air pollutant, nitrogen dioxide (NO2), in the United States.

We combined annual average NO2 concentration estimates from a temporal land use regression model with Census demographic data to estimate outdoor exposures by race-ethnicity, socioeconomic characteristics (income, age, education), and by location (region, state, county, urban area) for the contiguous United States in 2000 and 2010.

Estimated annual average NO2 concentrations decreased from 2000 to 2010 for all of the race-ethnicity and socioeconomic status groups, including a decrease from 17.6 ppb to 10.7 ppb (−6.9 ppb) in nonwhite [non-(white alone, non-Hispanic)] populations, and 12.6 ppb to 7.8 ppb (−4.7 ppb) in white (white alone, non-Hispanic) populations. In 2000 and 2010, disparities in NO2 concentrations were larger by race-ethnicity than by income. Although the national nonwhite–white mean NO2 concentration disparity decreased from a difference of 5.0 ppb in 2000 to 2.9 ppb in 2010, estimated mean NO2 concentrations remained 37% higher for nonwhites than whites in 2010 (40% higher in 2000), and nonwhites were 2.5 times more likely than whites to live in a block group with an average NO2 concentration above the WHO annual guideline in 2010 (3.0 times more likely in 2000).

Findings suggest that absolute NO2 exposure disparities by race-ethnicity decreased from 2000 to 2010, but relative NO2 exposure disparities persisted, with higher NO2 concentrations for nonwhites than whites in 2010.