The Role of Air Quality and Built Environment in Social Isolation and Cognitive Function among Rural, Racially/Ethnically Diverse Residents at Risk for Alzheimer's Disease - Both social isolation and cognitive decline are urgent threats to public health, as they predispose persons to Alzheimer’s disease and related dementias. Air pollution and the built environment are community-based factors that have been shown to adversely affect cognitive function. Individual factors such as social isolation and economic disadvantage further contribute to cognitive risk. Rural settings have more limited opportunities for social engagement, when compared to urban settings. These conditions converge to form a perfect storm of social isolation and accelerated cognitive decline, yet prior studies have not focused on rural, disadvantaged, ethnic minority residents. Using a multi-method approach, we propose to demonstrate how a uniquely vulnerable rural Florida population (N = 1087) are at risk for social isolation and decline in cognitive function due to the unique characteristics of the physical and social environment. We will recruit community-dwelling, non-clinical, dementia-free, middle aged and older adults from 5 communities in the Lake Okeechobee area of Florida for a 5-year study incorporating time-series individual social and cognitive measures and community-level measures of the physical and built environment. Apple watches will be used by a subsample of 120 participants representative of 5 communities to continuously monitor sensory data, daily routine and predefined activities for 2 months. Ecological momentary assessment (EMA) will be used to collect data daily over periods of agricultural burning and no burning. Using a combination of primary data collection, secondary data analysis, subsample continuous monitoring and EMA, we will examine the following aims over 36 months among rural, racially/ethnically, and linguistically diverse underserved community-dwelling adults aged 45 years and older: Aim 1: Examine the contribution of smoke-related PM2.5 exposures to SI and cognitive function, through multilevel growth modeling. Aim 2. Determine the effects of the built (e.g., retail destinations, park space) and social environment (e.g., crime SES) on social isolation and cognitive function through mixed linear modeling. Aim 3. Contextualize social isolation and cognitive function among residents from different racial/ethnic groups using EMA and sensor-derived behavior models with a subsample of 120 stratified by Lake O communities during burn and non-burn seasons.