Multi-Compartment PFAS Contamination and Risk Profiling in Kampala’s Urban Hydroscape: A Pre-Collapse Study of Kitezi, Lubigi, and Murchison Bay

Per- and polyfluoroalkyl substances (PFAS) have emerged as persistent pollutants of growing concern in urban hydrological systems. This study quantified PFAS concentrations across three environmental matrices open surface water bodies, landfill leachate from Kitezi, and Lubigi wetland treatment zones in central Uganda. Using liquid chromatography tandem mass spectrometry (LC-MS/MS), concentrations of eight PFAS compounds were analyzed, including PFOA, PFBS, PFHxS, and 6:2 FTS. Sampling was conducted at 12 representative points, and values were averaged across replicates to assess spatial trends. The findings revealed the highest mean concentrations in landfill leachate, with PFOA averaging 0.4154 µg/L and PFBS at 0.0463 µg/L, confirming landfills as major PFAS point sources. Lubigi wetland showed moderate accumulation—particularly PFHxS (mean: 0.1816 µg/L) likely due to its partial filtration role. Open water sites had the lowest concentrations, with PFBS and PFOA averaging 0.1263 µg/L and 0.3883 µg/L respectively, though variability existed across locations. These findings underscore the urgent need for a national PFAS monitoring framework, with regulatory focus on landfill leachate management, wastewater treatment optimization, and urban water reuse safety. This study represents the first PFAS spatial profile analysis in Uganda, contributing essential baseline data for regional policy and environmental health planning.