Traffic and Cooking Emissions Drive Exposure Disparities to Airborne Fine Particles in the United States

PROVAT SAHA, Albert A. Presto, Steven Hankey, Julian Marshall, Allen Robinson, Carnegie Mellon University

     Abstract Number: 271
     Working Group: Aerosol Exposure

Abstract
Although past studies have reported higher exposures of airborne fine particulate matter (PM2.5) for the racial-ethnic minority population in the US, the emission sources that drive the disparities are largely unexplored at a national scale. In this study, we combine high-spatial-resolution (census block level) national estimates of source-resolved PM2.5 components (e.g., traffic, cooking, and other) with publicly available demographic data (census block-group level) to determine exposure disparities by race-ethnicity, income, and urbanicity across the United States. Our results reveal that exposure disparities for total PM2.5 are mainly driven by the primary particle emissions from traffic and cooking sources. The contribution of cooking PM2.5 to exposure disparities is comparable to that of traffic. For both traffic and cooking primary PM2.5 components, exposures are much larger for racial-ethnic minority populations than white populations. Differences in income do not explain the racial-ethnic exposure disparities. Source-specific targeted emission reductions will be important to reduce the racial-ethnic exposure disparities for PM2.5 in the US.