Climate change impacts on population health: Modeling exposures to extreme heat and air pollution

Of the threats to public health linked to climate change, exposures to heightened air pollution and elevated temperatures rank high in national and international assessments. Climatic effects on air quality are well documented, especially for ozone, a secondary pollutant that increases in concentration with warmer temperatures. There is less certainty regarding the effects of climate change on fine particulate matter, air pollutant most hazardous to human health, and how a changing climate will affect the public health burden of air pollution overall. This research augments health impact studies of climate change by utilizing integrated modeling to better estimate the effects of exposures to climate-driven air pollution and heat on human health. The primary aims apply a mid-century summer climate projection for the eastern United States, the most populated region of the country that also faces a high burden of air pollution, as the foundation for health impact assessment. For this work, the US Environmental Protection Agency's Benefits Mapping and Analysis Program is used to combine environmental exposure, demographic, health incidence, and epidemiologic exposure-response models of risk to quantify the future burden of heat stress- and air pollution- related morbidity and mortality.;A secondary research aim focuses on improving estimates of air pollution-related health impacts in highly polluted settings. Large epidemiologic prospective cohort studies of chronic exposure to fine particulate matter and mortality risk are largely confined to areas with low to moderate concentrations and posit log-linear exposure-response relationships. However, levels of this pollutant in developing countries such as India are typically higher, causing unknown health effects. Recently, integrated exposure-response functions for high pollution exposure consistent with a biological saturation hypothesis and integrating risk estimates from exposures in ambient air, secondhand smoke, and active smoking have been posited. This research applies the revised functions to estimate the life expectancy impacts associated with pollution exposure in India by 2030 using modeled air pollution projections from the Greenhouse Gas and Air Pollution Interactions and Synergies model. Collectively, the exposure and epidemiologic risk modeling approaches applied in this dissertation constitute a framework for better quantifying heat- and air-quality related health impacts.