Environmental Justice and Inequality in Nitrogen Dioxide Air Pollution in the United States

We quantify environmental justice and inequality in ambient nitrogen dioxide air pollution concentrations for the U.S. population through a recently published dataset (Census Block Group level nitrogen dioxide concentration estimates from a national land use regression). Nationally, the relative percent difference (absolute difference) in population-weighted average nitrogen dioxide concentrations between high-income Whites and low-income Non-Whites is -19% (-3.4 ppb), and inequality in average nitrogen dioxide concentration (Gini Coefficient = 0.30; Atkinson Index = 0.11) is greater than inequality in average income (Gini Coefficient = 0.25; Atkinson Index = 0.079). Population-weighted average nitrogen dioxide  concentrations are higher for Urban Non-Whites than for Urban Whites across all Census household income groups. These national findings contribute to previous work documenting air pollution environmental justice and inequality within individual metropolitan areas.