Source-Specific Air Pollution Emissions Inequalities From 2011 to 2020 in Virginia

Air quality has improved in recent decades across most of the United States. However, decreases in pollution have not been uniform, potentially exacerbating inequalities in air pollution exposure by race and ethnicity. These inequalities exist, in part, because of spatial differences in source(s), for example, power plants or roadways. Determining which sources are driving inequality across racial and ethnic groups is critical to determining which policies (e.g., targeting power plant vs. vehicle emissions) would reduce inequalities. Our study determines which pollutant sources should be decreased to address inequalities in four pollutants (NO_x, SO₂, VOCs, and PM_2.5) in the Commonwealth of Virginia. We derived emissions from eight source categories for 134 Virginia counties from the National Emissions Inventory and the MOtor Vehicle Emissions Simulator mobile source emissions model. We used race and ethnicity data from the American Community Survey from 2011 to 2020. We applied the Atkinson Index to obtain a single summary of inequality for each source-pollutant pair (e.g., NO_x from electricity generation) across all race and ethnic groups. Most source category emissions were unequally distributed for at least once pollutant. Compared to other sources, electricity generation resulted in the largest inequalities across pollutants. Mobile sources increased in inequality from 2011 to 2020 even as emissions decreased. These results show the importance of identifying sources that contribute most to inequalities when developing policies to promote environmental justice.