PM2.5 attributable health disparities and distributional benefits of alternative National Ambient Air Quality Standards in the continental United States

Background & Aims: Racial, ethnic, and socioeconomic disparities in exposure to PM2.5 in the United States is well known. However, there is limited understanding of the magnitude of disparities in PM-attributable health effects and distributional benefits of policies, such as potential alternative National Ambient Air Quality Standards (NAAQS) currently being considered by EPA. Methods: We use fine scale air pollution, mortality and morbidity data, as well as new race- ethnicity stratified concentration response functions as inputs for a health impact assessment to determine the distribution of PM2.5 health burdens across race/ethnicity and poverty categories throughout the United States in 2015. Using a rollback approach, we examine the potential distribution of benefits of a 10 µg/m3 and 8 µg/m3 annual standard. We also explore the sensitivity of the model outputs to the different inputs. Results: In 2015, Black Americans experienced three times as many PM2.5-attributable related deaths per capita compared to all other races. The burden of PM-attributable asthma ED visits for non-white Americans were up to six times higher compared to white Americans. We find that an 8 µg/m3 alternative standard could avoid nearly 19,000 premature deaths and 11,500 respiratory emergency room visits. Mortality benefits for the 8 µg/m3 standard are three to four times higher than those for the 10 µg/m3 alternative standard. Per-capita mortality risk reductions for Black Americans are three times the rate of all other races and individuals with incomes ≤ 2X poverty line experience 30% higher mortality benefits under more protective PM NAAQS. Conclusions: These findings indicate that more protective NAAQS would provide some reduction in the magnitude of racial/ethnic and socioeconomic disparities in health burdens of air pollution exposure. Despite this, significant residual disparities would remain, suggesting that supplemental policy approaches would be needed to further alleviate the disparity in PM-attributable health burdens.