Updated Global Estimates of Respiratory Mortality in Adults [Formula: see text] of Age Attributable to Long-Term Ozone Exposure

BACKGROUND: Relative risk estimates for long-term ozone ([Formula: see text]) exposure and respiratory mortality from the American Cancer Society Cancer Prevention Study II (ACS CPS-II) cohort have been used to estimate global [Formula: see text] mortality in adults. Updated relative risk estimates are now available for the same cohort based on an expanded study population with longer follow-up. OBJECTIVES: We estimated the global burden and spatial distribution of respiratory mortality attributable to long-term [Formula: see text] exposure in adults [Formula: see text] of age using updated effect estimates from the ACS CPS-II cohort. METHODS: We used GEOS-Chem simulations ([Formula: see text] grid resolution) to estimate annual [Formula: see text] exposures, and estimated total respiratory deaths in 2010 that were attributable to long-term annual [Formula: see text] exposure based on the updated relative risk estimates and minimum risk thresholds set at the minimum or fifth percentile of [Formula: see text] exposure in the most recent CPS-II analysis. These estimates were compared with attributable mortality based on the earlier CPS-II analysis, using 6-mo average exposures and risk thresholds corresponding to the minimum or fifth percentile of [Formula: see text] exposure in the earlier study population. RESULTS: We estimated 1.04–1.23 million respiratory deaths in adults attributable to [Formula: see text] exposures using the updated relative risk estimate and exposure parameters, compared with 0.40–0.55 million respiratory deaths attributable to [Formula: see text] exposures based on the earlier CPS-II risk estimate and parameters. Increases in estimated attributable mortality were larger in northern India, southeast China, and Pakistan than in Europe, eastern United States, and northeast China. CONCLUSIONS: These findings suggest that the potential magnitude of health benefits of air quality policies targeting [Formula: see text] , health co-benefits of climate mitigation policies, and health implications of climate change-driven changes in [Formula: see text] concentrations, are larger than previously thought. https://doi.org/10.1289/EHP1390