Grantee Research Project Results
Environmental Determinants of Heat-Related RiskEPA Grant Number: FP917337
Title: Environmental Determinants of Heat-Related Risk
Investigators: Hondula, David M
Institution: University of Virginia
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Human Health: Public Health Sciences
Summertime heat waves are the leading cause of weather-related deaths and illness in the United States. Many of these deaths and related illnesses are believed to be preventable via appropriate intervention measures such as providing cooling centers for the isolated and elderly. Current warning systems succeed in forecasting hot periods but do not yet identify elevated risk zones at the sub-city scale. This proposed research will examine the geographic variability of environmental factors that contribute to local heat risk.
This research aims to identify smaller scale zones within cities where heat-related risk is highest and build empirical models that relate risk to a suite of explanatory variables, including environmental conditions and the underlying spatial demographic and social characteristics of the metropolitan populace. Daily mortality records for the previous 25 years have been obtained for seven major metropolitan areas in the United States. The aggregated zip-code mortality response on and following extreme heat events will be compared to the background rate using re-sampling techniques. Bootstrapped regression models will be employed to relate high-resolution meteorological, air pollution, demographic and land cover data to the spatial variability in heatrelated excess mortality. These models and related maps can be adapted by local agencies to improve heat management planning and response.
The research hypotheses center around the idea that significant variability in heat-related mortality exists within metropolitan areas. Models that explain a portion of this variability will likely include the environmental variables of air temperature, humidity and air quality, as well as demographic factors related to age, income and isolation. Furthermore, the local mortality response may be inconsistent from one heat event to another. It may be the case that heat events of greater duration particularly enhance death rates in the warmest places in cities. Localscale differences in the seasonality of mortality also may be present, attributable to a lack of preparation/awareness among these sensitive groups, of whom a larger percentage suffer in the first or second major heat wave each year.
Potential to Further Environmental / Human Health Protection
By identifying populations and localities that are most sensitive to mortality risk during high heat events, this research is directly targeted at protecting human health. Further, it may contribute to safeguarding the environment by providing additional insight into the efficient application of air-conditioning resources in particular geographies and the benefit of clean air. A closer examination of how the environment and demographics interact to shape patterns of heat-related deaths can lead to a healthier living environment for many Americans.