Residential mobility and multi-domain environmental exposures in Canada: Development of the Residential Mobility...

Residential mobility influences cumulative environmental exposures over the life course, yet few national datasets capture these dynamics across multiple exposure domains. This paper describes the development of the Residential Mobility Exposome File (ReMEF) and the cohort profile.

The ReMEF integrates individual-level residential histories from linked census and administrative data with annually resolved spatial measures of ambient air pollution, built and green environment characteristics, and ambient temperature. Annual k-means clustering was applied within each domain to classify exposures into three levels (low, medium, or high), followed by a temporal dominance rule to derive five-year exposure biographies. The analytical cohort included individuals aged 25 to 89 years with stable pre-baseline residence, enabling assessment of residential mobility patterns and exposure trajectories.

The ReMEF framework offers a scalable approach for leveraging residential mobility as a quasi-experimental feature of observational data. The standardized trichotomy (low, medium, high) applied across domains allows for comparability between different types of exposures. Residential mobility varied substantially by population group and socioeconomic characteristics. Certain racialized populations had relatively higher mobility, while First Nations and Inuit individuals were less likely to move. Distinct exposure biographies were observed across environmental domains, with racialized and immigrant populations more frequently residing in higher ambient air pollution clusters.

The ReMEF provides a resource analytical file and is useful for natural experiments that aim to leverage residential mobility to examine cumulative, multi-domain environmental exposures and disparities over time. The analytical file creation code is available upon request, and it can be recreated using the source data following approval.