Project Summary/Abstract Understanding environmental health disparities for older persons is critical given the unprecedented aging of the population, with 20% of US persons anticipated to be >65y by 2030, and the elder population becoming more racially and ethnically diverse. Older persons can be more affected by environmental and socio- economic status (SES) factors due to baseline health, changing metabolism, or larger cumulative exposures. Harmful environmental exposures, such as air pollution, often occur in communities facing SES stressors including deteriorating housing, poor access to health care, high unemployment, crime, and poverty, which may exacerbate negative health effects. This phenomenon is most pronounced for low income and minority communities and underlies health disparities. Identifying the most harmful environmental and social factors and the subpopulations of elderly that are most affected is of paramount importance. Although it is widely agreed that multiple environmental and SES factors affect health, little is known about their complex interactions. Our long-term objective is to investigate how environmental and SES factors jointly contribute to health disparities in the older population. We consider disparities in two separate but related forms: 1) differences in exposures (e.g., pollution levels) to environmental and SES factors; and 2) differences in health response (e.g., relative risk) from exposures to environmental and SES factors. This proposal brings together investigators with a long history of working on environmental health disparities and related advanced spatial and statistical analyses. Our aims are to: 1) calculate differences in exposures to environmental and SES factors, considered individually and collectively, for an older population (>65y) in Michigan and North Carolina, and to construct a highly resolved spatio-temporal data architecture for analysis; 2) calculate differences by subpopulation (e.g., race/ethnicity, age, sex, community SES) for associations between environmental and SES factors and cause- specific emergency cardiovascular and respiratory hospital admissions, emergency department visits, and mortality; and 3) combine disparities in exposures and disparities in health response to calculate overall environmental health disparities. Environmental and some SES factors represent modifiable risks through which we can improve health in our aging population. Analyses will identify the most effective foci for intervention and policy engagement by identifying the most significant common contributors to environmental health disparities for the elderly, thereby directly contributing to NIEHS's mission to discover how the environment affects people in order to promote healthier lives.