Evaluation and source apportionment of persistent decadal air pollution disparities in Kansas City, Missouri

The Midwestern city of Kansas City, Missouri, has a long history of redlining practices that have deeply segregated the city. This segregation persists to the present, making Kansas City an important place to study pollution disparities. However, the monitoring landscape in Kansas City is sparse, leading to unique challenges in identifying pollution disparities. Here, we examine disparities in fine particulate matter (PM_2.5) in the Kansas City Metropolitan Area (KCMA) across demographics and present methodology that can be applied to other cities with sparse monitoring infrastructure. We examine quantitative decadal trends in disparities from 2010 to 2019 using Census tract demographic information and PM_2.5 modeled at the intra-urban scale. We find statistically significant (<i>p</i> < 0.05) differences in PM_2.5 distributions between predominantly White communities and communities of color that persist throughout the past decade in all seasons. On an annual basis, majority Black and African-American (BAA) Census tracts have experienced on average 2.7% (0.2 µg m^-3) higher PM_2.5 burden than majority White American (WA) Census tracts. Higher disparities occur between the most and least WA Census tracts (3.4%; 0.3 µg m^-3). The largest disparities in PM_2.5 occur during winter (6.8%; 0.7 µg m^-3). Despite large overall decreases in PM_2.5 mass concentrations of 27%, the disparity between communities remains remarkably persistent over time, indicating that the pollution gap between communities has not been narrowed by emissions regulations. Source attribution simulations performed via the Intervention Model for Air Pollution (InMAP) suggest that non-point sources such as residential heating contribute primarily to observed PM_2.5 disparities. This suggests that the air pollution disparity in Kansas City can be at least partially addressed through mitigation efforts targeting non-point sources of pollution.<i>Implications</i>: It is widely acknowledged in the field of environmental justice that communities of color are disproportionately exposed to higher levels of pollution than predominantly White communities in the United States. In Kansas City, which has not been evaluated for air quality-related environmental justice concerns before, we note a PM_2.5 disparity along demographic lines and find that non-point emissions contribute the most to this observed disparity. Our results suggest that efforts targeting pollution from non-point sources (e.g., anthropogenic dust, residential heating, commercial combustion, and waste disposal) could be critical to reducing pollution disparities in the region alongside reductions in total air pollution.