A Scoping Review of Trends in Atmospheric Pollution Research in Uganda (1990-2025)

Air pollution is an emerging environmental and public health concern in Uganda; however, the evolution of atmospheric pollution research in the country has not been comprehensively synthesized. This study presents a scoping review of peer-reviewed literature published between 1990 and 2025, examining the temporal trends in research output, key pollutants investigated, the study environments and research methodological approaches. A structured literature search was conducted across three academic databases (Google Scholar, Web of Science, and PubMed) and eligible studies were screened and analysed using a standardized data extraction framework. The results reveal highly uneven growth in research output, with minimal activity prior to 2010, followed by rapid expansion after 2015 and a pronounced surge between 2020 and 2025. Particulate matter (PM_2.5 and PM₁₀) dominated the literature across all periods, while gaseous pollutants such as NO₂, SO₂, CO, and O₃ were comparatively underrepresented. Most studies were conducted in urban environments, particularly in Kampala, whereas rural ambient monitoring remained limited. Methodologically, the literature evolved from proxy-based and gravimetric approaches to the increased use of low-cost sensors, portable monitors and satellite-derived data. Despite recent advances, the predominance of short-term and spatially constrained studies highlights persistent gaps in long-term and nationally representative air quality monitoring. This review synthesizes trends, methodological developments, and evidence gaps in atmospheric pollution research in Uganda over a 35-year period, providing a foundation for strengthening future monitoring and policy frameworks.