Climate change impacts on projections of excess mortality at 2030 using spatially varying ozone-temperature
Wilson, A., B. Reich, C. Nolte, T. Spero, B. Hubbell, AND A. Rappold. Climate change impacts on projections of excess mortality at 2030 using spatially varying ozone-temperature. Journal of Exposure Science and Environmental Epidemiology . Nature Publishing Group, London, Uk, 27(1):118-124, (2017).
Changes in meteorological conditions, induced by global climate change, are expected to alter the distribution of ozone, and the frequency of peak ozone concentrations exceeding the US National Ambient Air Quality Standard (US NAAQS).This study estimates the mortality burden attributable to changes in ground-level ozone due to climate change and projected through 2030.
We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995-2005) and near-future (2025-2035) time period while incorporating a non-linear and synergistic effect of ozone and temperature on mortality. We simulate air quality from climate projections varying only biogenic emissions and holding anthropogenic emissions constant, thus attributing changes in ozone only to changes in climate and independent of changes in air pollutant emissions. We estimate non-linear, spatially varying, ozone-temperature risk surfaces for 94 US urban areas using observeddata. Using the risk surfaces and climate projections we estimate daily mortality attributable to ozone exceeding 40 p.p.b. (moderate level) and 75 p.p.b. (US ozone NAAQS) for each time period. The average increases in city-specific median April-October ozone and temperature between time periods are 1.02 p.p.b. and 1.94 °F; however, the results variedby region . Increases in ozone because of climate change result in an increase in ozone mortality burden. Mortality attributed to ozone exceeding 40 p.p.b. increases by 7.7% (1 .6-14.2%). Mortality attributed to ozone exceeding 75 p.p.b. increases by 14.2% (1.628.9%). The absolute increase in excess ozone mortality is larger for changes in moderate ozone levels, reflecting the larger number of days with moderate ozone levels.