Online Program

Modeling Interactive Mortality Impacts of Climate Change-Driven Exposures to Ozone and Extreme Heat in the Eastern US

Wednesday, November 4, 2015 : 10:50 a.m. - 11:10 a.m.

Vijay Limaye, PhD, U.S. Environmental Protection Agency, San Francisco, CA
Jonathan A. Patz, MD, MPH, Global Health Institute, Dept. Population Health Sci., & Nelson Institute for Environmental Studies, University of Wisconsin, Madison, WI

Climate change is expected to increase the frequency and duration of heat waves around the world.  Warmer weather is also predicted to exacerbate levels of ambient air pollution, a risk factor for significant mortality and morbidity worldwide.  While the independent effects of chronic exposures to extreme heat and air pollution on public health are well established, evidence is emerging for effect modification when these exposures are experienced simultaneously. Exposure to ozone (O3) irritates the lungs and modulates a nervous system response, making people more vulnerable to the effects of heat stress.  Because the chemical formation of O3 in the atmosphere is temperature-dependent, higher surface temperatures are expected to worsen O3 pollution on average.  These joint risks are especially salient in urban settings.

We use the U.S. Environmental Protection Agency’s Benefits Mapping and Analysis Program (BenMAP) and a suite of climate and air pollution models to estimate the number of mid-century annual excess deaths attributable to joint extreme heat and O3 exposures across in the eastern US.  In our modeling spanning June-August, 8-hour maximum O3 levels rise by an average of 4.6 parts per billion (ppb), and the average apparent summer temperature (incorporating the effects of humidity) increases by 4.5 °C.  Modeling of health impacts using BenMAP suggests substantial mid-century excess mortality due to each of these climate-sensitive exposures.  Extreme heat is expected to cause 6,736 excess deaths (95% Confidence Interval: 4,277-9,182) and ozone 6,507 excess deaths (95% CI: 3,077-9,911).  Interactive effects of these joint exposures cause 281 additional deaths (95% CI: 135-426) across the region, particularly concentrated in the midwest and northeast.  Our analysis has identified significant health risks attributable to combined exposures, and this work provides a proof-of-concept to demonstrate how interdisciplinary modeling can help to quantify the complex, interactive health effects of climate change.

Learning Areas:

Environmental health sciences

Learning Objectives:
Identify the independent health effects of extreme heat and air pollution Name two ways in which climate change is expected to impact heat waves around the world.

Keyword(s): Climate and Health, Air Pollution & Respiratory Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am the lead epidemiologic researcher on a National Institute of Environmental Health Sciences grant to quantify the direct and indirect effects of climate change on the health of populations in the eastern United States.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 5093.0: Climate Change III