Abstract/Summary: We propose an administrative supplement to enhance the existing longitudinal Dunedin Study with, per NOSI-AG-22-022, “new exposure measures and mechanisms linking exposures to AD/ADRD outcomes.” The NOSI calls for new research infrastructure that “addresses the role of diverse physical, chemical, social, psychological, and economic exposures across multiple levels and across the life course in the etiology and social disparities” of AD/ADRD. The Dunedin Study, now in its 5th decade, has led the field in tracking social, psychological, and economic exposures since our cohort’s birth in 1972, using multidisciplinary methods spanning sociology, psychology, medicine, dentistry, sensory science, and economics. Here we propose to collect chemical and physical exposure data at Dunedin Phase 52. Doing so will make the Study one of the world’s first truly “exposomic” investigations of life-course brain aging and AD/ADRD risk. We propose to measure toxic metals, home environmental quality, and neighborhood environmental quality.