SPATIAL VARIATION OF PM2.5 AIR POLLUTION AND ITS ASSOCIATED HEALTH IMPLICATIONS WITHIN BENIN CITY METROPOLIS

Air pollution remains one of the most pressing environmental and public health challenges facing rapidly urbanising cities, and fine particulate matter (PM2.5) is of particular concern due to its ability to penetrate deep into the respiratory system and bloodstream. This study assessed the spatial and temporal variation of PM2.5 concentrations within Benin Metropolis, Edo State, Nigeria, using data collected from three representative monitoring sites: The University of Benin, the Edo State Secretariat, and the Edo Geographic Information Service, over a twelve-month period from December 2024 to December 2025. Daily average PM2.5 concentrations were measured using low-cost sensors and converted into corresponding Air Quality Index values to assess associated health risks. Results showed that PM2.5 levels frequently exceeded international health guidelines across all sites, with the University of Benin consistently recording the highest and most erratic concentrations, particularly during the harmattan season, while levels generally declined during the rainy season. The study recommends the establishment of a continuous, site-specific air quality monitoring network, public advisory systems during high-pollution periods, and stricter controls on generator use, vehicular emissions, and dust-generating activities to guide effective air quality management and public health policy within the metropolis.