JMIR Publications

ABSTRACT

Background:

Environmental exposure, including green-blue space and walkability, may influence mental health through various physiological pathways. Traditional methods have limitations in capturing dynamic environmental exposure effects on mental health

Objective:

To investigate the associations between minute-level environmental exposure and stress-related biomarkers using GPS-based measurements and wrist-worn biosensors in an urban population.

Methods:

This prospective observational study will recruit 750 participants (aged 18-80) in Hong Kong from September 2024 to Spring 2026. Participants will undergo a one-week experiment wearing biosensors and carrying GPS devices while completing daily surveys and entry/exit questionnaires. Primary outcomes include digital biomarkers (electrodermal activity, blood volume pulse, skin temperature) from wrist-worn sensors. Secondary outcomes comprise physical activity metrics from accelerometer data and environmental exposure assessments including mobility barriers, land use mix, road accessibility, thermal conditions, air pollution exposure, urban density and green-blue space access. Focus groups will be conducted to refine study protocol and assess device wearing experience.

Results:

As of September 2025, 180 participants have completed the one-week experiment. The study has received ethical approval (HERC Award Number: EA240125 and EA240514), completed pilot testing with 150 participants, and implemented protocol refinements based on focus group feedback. Data collection will continue until Spring 2026.

Conclusions:

This study’s innovative integration of continuous environmental monitoring and stress-related biomarker may provide new insights into environment-health relationships. Findings will inform public health initiatives for mental well-being promotion and urban planning interventions.