ABSTRACT Fine particulate matter air pollution has been found to be associated with increased inflammation, respiratory disease, cardiovascular event risk, and cognitive changes and risk for Alzheimer’s Disease and Related Dementias (ADRD). Prior research has established that those exposed to higher levels of air pollution have higher levels of accumulated amyloid-beta (Aβ) and tau in frontal cortex at autopsy, higher error rates on cognitive function assessments, and lower scores on memory and both verbal and non-verbal intelligence assessments. In the US, exposure to high levels of air pollution is common, with substantial heterogeneity that is often associated with socioeconomic and racial/ethnic differences. Most research on the health effects of air pollution is based on outdoor ambient air quality measurements often supplemented by monitoring. This methodology cannot address contributions from indoor air quality and mobility in daily life, has limited geospatial precision, and cannot address individual differences in exposure and contextual factors (e.g., time spent indoor vs. outdoor, proximity to pollution sources, smoking, antiquated heating materials, and floor levels in buildings. This exposure misclassification likely results in significant biases towards the null in the estimation of the effects of air pollution. Commercially available, validated, wearable air quality sensors can accurately characterize person-specific air pollutant exposures to better understand how they relate to ADRD, and these will be used to assess exposure in this project. This Project, part of a renewal of the Einstein Aging Study (EAS; NIA P01 AG003949), will follow 767 diverse participants aged 60+ (dementia free at baseline) for up to 5 annual waves of data collection, collecting person-specific indices of exposure to fine particulate matter air pollution (PM1, PM2.5) to investigate the association of fine particulate matter exposure with cognition function and AD/ADRD (Specific Aim 1), biomarkers of neurodegeneration and vascular brain pathology (Specific Aim 2), and social determinants of health (Specific Aim 3). Establishing the association of person-specific air pollution exposure with momentary cognitive function, a biological pathway for that association, and how this association is modified by social determinants will yield insight into individual susceptibility and resilience to acute and chronic environmental stressors.