PROJECT SUMMARY Racial/ethnic minorities are at a higher risk for age-related cognitive dysfunction compared to non-Hispanic (NH) Whites. The mechanisms underlying this disparity are not well understood. Exposure to air pollution may be one important driver of these disparities. Recent epidemiologic studies suggest that increased exposure to air pollution increases risk of Alzheimer’s disease and related dementias (ADRD). Compared to NH Whites, racial/ethnic minorities are more likely to live in neighborhoods with higher levels of air pollution. No prior research, however, has quantified the contribution of air pollution as a driver of racial/ethnic disparities in ADRD. The scientific objective of this research is to evaluate air pollution as a potential driver of racial/ethnic disparities in ADRD and to understand the potential implications of air quality regulations on ADRD risk. We will focus this research on disparities between Mexican American and NH White racial/ethnic groups. This project uses an innovative approach to combine data from two existing cohort studies: The Sacramento Area Latino Study on Aging and the Ginkgo Evaluation of Memory Study. We will harmonize outcome and exposure data from the two cohorts and examine whether the effect of air pollution on ADRD risk varies across racial/ethnic groups. We will also examine whether air pollution drives disparities in ADRD by examining racial/ethnic differences in air pollution exposure, individual- and neighborhood-level susceptibility to air pollution. Finally, we will measure the potential impacts of air quality regulations on ADRD risk, using air quality regulations related to seaports as an example. The proposed research will leverage advanced causal inference methods including econometric quasi-experimental study designs to carry out the proposed research. This research plan is complemented by a mentored training plan that builds upon the candidate’s background in environmental epidemiology and includes coursework, structured mentoring, and experiential learning in the following areas: 1) racial/ethnic disparities in ADRD, 2) environmental health disparities, 3) harmonization of cognitive data, 4) air quality regulations, and 5) application of advanced social epidemiology and causal inference methods. Together, the proposed research and training plan will prepare the candidate for a successful independent research career dedicated to identifying environmental determinants of healthy aging, especially in racial/ethnic minority populations.