# Home Environmental Factors Associated with Health Outcomes in Community-Dwelling Older Adults

## TL;DR

This study explores how indoor environmental factors affect sleep, mental, and cognitive health in older adults living at home.

## Contribution

The study introduces a comprehensive analysis linking self-reported and sensor-based indoor environmental data to health outcomes in older adults.

## Key findings

- Lower perceived environmental comfort was significantly associated with poorer sleep quality and increased insomnia severity.
- Higher CO2 levels were linked to poorer delayed recall, and higher humidity was associated with increased insomnia severity.
- Evening light exposure correlated with higher stress levels in older adults.

## Abstract

Older adults spend a substantial proportion of their time indoors, making them particularly vulnerable to home environmental factors. However, existing research has focused on outdoor exposures near residential addresses, leaving a critical gap in understanding the scope of indoor environmental impacts on aging. We investigate the associations between indoor environment and health outcomes (sleep, mental, and cognitive health) in community-dwelling older adults without dementia, using the baseline data from an ongoing RCT. Indoor environment includes self-reported environmental comfort—encompassing light, air quality, temperature, and noise—and continuous 24/7 sensor-based measurements of air pollution (PM2.5, CO2, NOx, and TVOCs), humidity, temperature, light, and sound levels. Sleep health was assessed via self-reported measures (Pittsburgh sleep quality index [PSQI], and insomnia severity) and objective measurement devices—ActiGraph and ambulatory EEG. Cognitive function was evaluated using the Everyday cognition scale (ECog) and the NIH Toolbox, while mental health was measured through the Geriatric depression scale, Geriatric anxiety scale, and Perceived stress scale. Our findings (n = 39) showed lower perceived environmental comfort was significantly associated with poorer sleep quality (PSQI, r = 0.36), increased insomnia severity (r = 0.32), worsened mental health (depression, r = 0.34; anxiety, r = 0.36; stress, r = 0.35), and lower cognitive function (ECog, r = 0.32). Additionally, increased evening light exposure correlated with higher stress (r = 0.75), higher CO2 levels were associated with poorer delayed recall (r=-0.64), and higher humidity was linked to increased insomnia severity (r = 0.64). These findings highlight the need for targeted interventions to improve indoor environmental conditions, which may mitigate risks to sleep, mental, and cognitive health in community-dwelling older adults.