Metals and metalloids in frequently consumed fish species from Koka and Aba Samuel Reservoirs in central Ethiopia

Abstract

Abstract The deposition of Metals and metalloids in freshwater has direct impacts on the ecosystem’s health. Consequently, the objective of the present study was to determine the levels of metals and metalloids in the organs of freshwater fish species from Lake Koka and Aba Samuel Reservoir in Ethiopia in February and August 2023. The analysis was performed using an ICP-OES after the hot plate digestion. Statistical analyses indicated that the metal levels in fish organs differed significantly ( p < 0.05). The mean build-up trend of these elements in the organs of fish was liver > gill > muscle. There exists a substantial difference in the accumulation of Metals and metalloids in muscle and liver ( p < 0.05). The trace metal accumulation pattern for fish types was C. carpio > C. gariepinus > O. niloticus . Seasonal variation of the trace metal concentrations in fish organs indicated elevated concentrations in the dry season. The findings demonstrate that metals and metalloids accumulate in fish from Lake Koka and Aba Samuel Reservoir, with Pb exceeding permissible limits in some samples. Although health risk assessment indicated generally acceptable non-carcinogenic and carcinogenic risks, elevated Pb levels and widespread metal occurrence warrant continuous monitoring and management to protect ecosystem and public health.