Radioecological Characterization and Natural Radioactivity Levels in Fish From Kalokol and Long’ech Markets, Lake Turkana, Kenya

Abstract

Radioecological assessments are vital for shielding human populations from the harmful impacts of radiation. They generate essential data to strengthen legal frameworks for radiation safety and raise public awareness. This study examined natural radioactivity levels in fish sourced from Lake Turkana, specifically the Long’ech and Kalokol markets. Using a high-purity germanium (HPGe) detector, the research measured the activity concentrations of 232Th, 238U, and 40K in various fish species and evaluated radium equivalent activity. 40K showed the highest activity concentrations across all fish species (mean 476.95 Bq/kg), while 238U and 232Th were significantly lower. Radium equivalent activity (Raeq) varied by species, with African Catfish recording the lowest value (66.87 Bq/kg), Nile Tilapia intermediate (94.93 Bq/kg), and Nile Perch the highest (106.93 Bq/kg) due to elevated 238U. These differences reflect species-specific feeding habits, habitats, and metabolic processes influencing radionuclide bioaccumulation. Compared to other global water bodies, fish from Lake Turkana exhibit comparable or lower levels of 232Th(15.00 Bq/kg) and 238U (31.40 Bq/kg), but notably higher concentrations of 40K (476.95 Bq/kg). Despite the elevated 40K, the overall Raeq (89.58 Bq/kg) remains within safe comparative limits, aligning closely with regions like the Eastern Libyan Coast (103.40 Bq/kg).