Ground-Level Ozone-Related Health Impact of Climate Change in the U.S

Ground-level ozone is an air pollutant associated with risk of adverse human health effects. Climate change may result in increased ground-level ozone, which could potentially produce significant health burden. We examine the health impact of climate change in 2050 in the U.S., explicitly taking into account the existing Ozone National Ambient Air Quality Standards (NAAQS).

Using modeling results from seven climate change-air quality models, we classify U.S. areas in terms of whether ozone concentrations are below or above the ozone standard. In the areas where the ozone concentration is expected to be ≤75 ppb under the considered climate change scenarios, the increased public health burden represents the impact of climate change. For areas that are in violation, ozone levels are assumed to be reduced as a result of NAAQS and additional health burden is avoided. The analyzed health effects include premature mortality, respiratory hospital admissions, asthma emergency department visits, school loss days and minor restricted activity days.

Without accounting for the ozone NAAQS, estimates of the annual national ozone-related non-accidental mortality for ca. 2050 ranged from ~ 900 deaths avoided due to climate change to ~ 3,900 deaths attributable to climate change, depending on the climate change–air quality modeling system, population projection, and concentration–response relationship used. With the NAAQS in place, the estimated change in deaths ranged from ~ 2,600 deaths avoided due to climate change to ~ 2,000 deaths attributable to climate change.

Our paper highlights the nexus between climate change and air quality management policy. With climate change, the ozone NAAQS could confer additional social benefit to the public.