Assessing the health benefits from nationwide reductions of ozone air pollution

Tropospheric ozone is a criteria air pollutant correlated with significant negative health effects, including increased mortality and cardiopulmonary/ respiratory morbidity. The current EPA ozone standard is 75ppb, but measured ambient values often exceed this level. Using the BenMAP software, we quantified the prevented morbidities and mortalities from “rolling back” ozone concentrations to attain three 8-hr NAAQS: 75, 70, and 60 ppb; where the two lower alternatives reflect the upper and lower-bound range of EPA Clean Air Scientific Advisory Committee recommended values and are proposed targets for a revised ozone standard. Using a suite of short-term ozone risk estimates, the annual avoided cases of all-cause premature mortality range from 290-410 at 75ppb to 1,890-2,660 at 60ppb. Attaining the 75ppb standard prevents 290 emergency room visits, 250 hospital admissions, 550,250 acute respiratory symptoms, and 237,100 lost school days. Rollbacks to the 70 and 60 ppb 8-hr maximum levels yield additional health benefits. Mapping of scenario results display regional variations in benefits, with the greatest positive impact observed in New York, Los Angeles, Philadelphia, and Riverside, California.