Potential health risks from contaminated fish in Lake Victoria: A 25-year systematic review of pollutants and management challenges
By Nelson Mwebesa, Ivan Oyege, Dennis Ssekimpi, Jackson Kisingu Ndolo, and Moses Egor
Sci Total Environ
November 5, 2025
DOI: 10.1016/j.scitotenv.2025.180861
Lake Victoria is the largest freshwater lake in East Africa, sustaining the livelihoods of over 40 million people. However, its fisheries face increasing threats from contamination by potentially toxic elements (heavy metals), persistent organic pollutants, and emerging contaminants. This systematic review integrates 25 years (2000-2025) of research, analyzing primary studies on fish contamination across Uganda, Kenya, and Tanzania. The review assessed the occurrence, bioaccumulation, and toxicology of pollutants, as well as their health implications and management strategies. Mercury was the dominant pollutant of concern, with concentrations ranging from 3.4 ng/g wet weight in Nile tilapia (Oreochromis niloticus) to very high values of 335,000 ng/g dry weight in silver fish from mining regions, exceeding international safety limits. Other detected contaminants included organochlorine pesticides, polychlorinated biphenyls, endosulfan, polybrominated diphenyl ethers, polychlorinated dibenzo-p-dioxins and furans, per- and polyfluoroalkyl substances, and microplastics. Bioaccumulation patterns revealed higher contaminant loads in the liver tissues of all fish, particularly in Nile perch (Lates niloticus). The health risks associated with these pollutants include neurotoxicity, carcinogenicity, endocrine disruption, and ecosystem-level impacts. However, significant knowledge gaps remain for newer pollutants, including pharmaceutical and personal care products, plasticizers, and modern pesticides, which have not been assessed in Lake Victoria fish. Furthermore, spatial coverage is uneven, with most islands and some inshore fishing zones lacking data. This review presents the first comprehensive synthesis of fish contamination data in Lake Victoria, providing a foundation for future scientific research, policy, and transboundary management, while also offering a transferable framework for addressing similar pollution challenges in tropical inland waters globally.
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