Integrating the physical environment into Alzheimer's disease and Alzheimer's disease related dementias research: A Gateway Exposome Coordinating Center (GECC) agenda on gaps and priorities.

The physical environment is an important yet underexplored domain in Alzheimer's disease and Alzheimer's disease and related dementias (AD/ADRD), shaping exposures and health-related behaviors across the life course. We identified key gaps and priorities for incorporating physical environment measures into population-based research, with an emphasis on geospatial data that can be applied in large cohorts and administrative datasets. The Gateway Exposome Coordinating Center (GECC) synthesized input from six town halls, a 4-day expert workshop, and the literature to build consensus on priority physical environment exposures and a roadmap for advancing exposure data. We also identified four methodological imperatives: developing pathway-relevant metrics, addressing temporality, incorporating behavior into exposure estimation, and integrating co-occurring exposures. Advancing guidance and exposure metrics in these areas can support prevention-oriented, policy-relevant research and improve understanding of how physical environments influence brain health.