Air Pollution Inequality in Malawi: A Comparative Regional Analysis Using Sentinel-5P and Cloud-Based Geospatial Tools

Background Air pollution is an escalating environmental and public health issue in Malawi, driven by rapid urbanisation, industrial growth, and biomass burning. Understanding the spatiotemporal dynamics of major atmospheric pollutants is essential for effective mitigation strategies. Objective To analyse the spatiotemporal trends and seasonal variations of nitrogen dioxide (NO₂), sulphur dioxide (SO₂), carbon monoxide (CO), and ozone (O₃) across Malawi’s Central, Northern, and Southern regions from 2019 to 2024. Method To extract pollutant concentrations, satellite remote sensing data from Sentinel-5P were processed in Google Earth Engine (GEE). Spatial and temporal analyses in a GIS environment quantified regional variability and seasonal patterns. Results The Central Region recorded consistent NO₂ increases during the dry season, with June levels rising by 48% (R² = 0.92), largely from urban and industrial emissions. Northern and Southern regions showed highly variable NO₂ and SO₂ trends, including a + 7579% NO₂ spike in the Southern Region linked to biomass burning and new industrial activities. Seasonal CO peaks shifted, with Southern October values up 53.5%. O₃ concentrations rose notably in dry months, especially in the Northern Region (+ 6.45% in October). Conclusion Malawi's distinct regional and seasonal pollution profiles are shaped by anthropogenic and climatic drivers, requiring targeted interventions. Unique Contribution: This is the first high-resolution, multi-year spatial analysis of four key pollutants across Malawi’s three regions using Sentinel-5P, providing critical evidence for air quality policy and climate-resilient planning. Key Recommendation: Establish a nationwide air quality monitoring network, strengthen emission control enforcement, and integrate air quality management with climate adaptation strategies.