Environmental inequality: Air pollution exposures in Californiaʹs South Coast Air Basin

Environmental inequality is quantified here using linear regression, based on results from a recent mobility-based exposure model for 25,064 individuals in Californiaʹs South Coast Air Basin [Marshall et al., 2006. Inhalation intake of ambient air pollution in Californiaʹs South Coast Air Basin. Atmospheric Environment 40, 4381–4392]. For the four primary pollutants studied (benzene, butadiene, chromium particles, and diesel particles), mean exposures are higher than average for people who are nonwhite, are from lower-income households, and live in areas with high population density. For ozone (a secondary pollutant), the reverse holds. Holding constant attributes such as population density and daily travel distance, mean exposure differences between whites and nonwhites are 16–40% among the five pollutants. These findings offer a baseline to compare against future conditions or to evaluate the impact of proposed policies.