Association of fine particulate matter and wet-bulb globe temperature with depression incidence in a community-based longitudinal study

This study investigated the associations of particulate matter (PM_2.5/PM₁₀) and wet-bulb globe temperature (WBGT) with incident depression. Participants were recruited from the Taiwan Biobank. Exposure to air pollutants and WBGT was calculated using geospatial artificial intelligence (Geo-AI) estimation. Depression was assessed via self-reported questionnaires, and multivariable-adjusted Cox regression models were used for analysis. A total of 21,445 participants were enrolled, among whom 263 (1.2%) developed depression over an average follow-up period of 43 months. Participants in the highest quartile of PM_2.5 exposure had a significantly increased depression risk (HR 1.844, 95% CI 1.315-2.587). PM₁₀ exposure was also positively associated with depression, though the association was less consistent across analyses. The greatest risk was observed among individuals residing in areas with both elevated PM and WBGT levels. Higher exposure to PM_2.5 was consistently associated with increased depression risk. These findings highlight the potential combined effects of air pollution and heat stress on mental health in subtropical regions.