PM2.5 Trajectory Classes and Spatial Investment Patterns in Portugal

The article examines temporal trajectories of fine particulate matter (PM2.5) across Portugal’s 308 municipalities (2019–2025) in relation to seasonal wind patterns and municipal economic and cultural investment. Annual PM2.5 concentrations and wind statistics were obtained from CAMS NRT/ECMWF satellite data. After standardising and clustering the PM2.5 distribution with k-means, twenty-nine municipalities closest to cluster centroids were compared using 2024 fiscal data. Results reveal marked spatial disparities in PM2.5 exposure linked to seasonal regimes and investment profiles. High economic-cultural investment areas often align with high-pollution trajectories, whereas low investment correlates with lower levels, both reflecting seasonal environmental and social patterns.