EFFECT MODIFICATION BY COMMUNITY CHARACTERISTICS ON THE SHORT-TERM EFFECTS OF OZONE EXPOSURE AND MORTALITY IN 98 U.S. COMMUNITIES
Previous research provided evidence of an association between short-term exposure to ozone and mortality risk and of heterogeneity of the risk across communities. We investigated whether this heterogeneity can be explained by community-specific characteristics: race, income, education, urbanization, transportation use, particulate matter and ozone levels, weather, and use of air conditioning. Our study includes data for 98 U.S. urban communities for 1987 to 2000 from the National Morbidity, Mortality, and Air Pollution Study (NMMAPS), U.S. Census, and American Housing Survey. On average across the communities, a 10 ppb increase in the previous week’s ozone was associated with a 0.52% (95% posterior interval (PI): 0.28, 0.77%) increase in mortality. We found that community-level characteristics modify the relationship between ozone and mortality. Higher effect estimates were associated with higher unemployment, fraction of the population Black/African-American, and public transportation use, and lower temperatures or prevalence of central air conditioning. These differences may relate to underlying health status, differences in exposure, or other factors. Results show that some segments of the population may face higher health burdens of ozone pollution.