EXPANSE Urban Labs: a panel study to deepen understanding of healthy urban living environments

EXPANSE Urban Labs aims to evaluate uncertainty in exposure assessment, sources of bias, and generalizability of various residential long-term exposure-disease associations reported in large cohort consortia. The objective of this paper is to i) present this large panel study design and methods; ii) describe participants and exposome components in the five centers; and iii) illustrate the study principle in a case study focusing on depression, greenspace, and heat.

Data was collected between June 2022 and June 2024 in CH (Basel, Switzerland), ES (Barcelona, Spain), GR (Athens, Greece), NL (the Netherlands), and PL (Lodz, Poland). Participants completed a baseline questionnaire, additional questionnaires repeatedly over 1.5 years, and a two-week measurement campaign consisting of wearing a GPS tracker and a silicone wristband paralleled by a time activity diary; personal and residential PM_2.5 monitoring in a subsample; and self-collection of dried capillary blood spots.

3782 Participants were on average 48.8 years, 60.9% were females and 49.3% highly educated. Between 16.9% (PL) to 91.0% (CH) completed the measurement campaign. Residential greenness (NDVI within 500 m buffer) was highly correlated with mobility-weighted greenness but not with perceived greenspace quality. Mobility-weighted greenness varied by activity and day of the week. Perceived heat in summer was highest in ES. Ventilator use during night was lowest in CH and NL. A suggestive and exemplary, statistically non-significant association between perceived heat and depression was only evident if perceived greenspace quality is low and no ventilator use is reported.

This paper sets the stage for future analyses of the Urban Labs data. The Urban Labs data will inform on the priority of additional data to be obtained in future large cohort follow-up questionnaires on urban dwellers' perception and use of the environment and on adaptation measures.