Journal of Applied Chemical Science International

Cassava (Manihot esculenta Crantz) is the predominant root crop cultivated across Akwa Ibom State, Nigeria, constituting a critical component of local food security. One of its advantages is that it can be processed into different edible forms. This study investigated the efect of soil physicochemical properties on the transfer of naturally occurring radionuclides (²³⁸U, ²³²Th, and ⁴⁰K) from agricultural soils into cassava tubers cultivated in four Local Government Areas (LGAs): Abak, Ikot Ekpene, Ukanafun, and Etim Ekpo. Soil and cassava samples collected were thirty-two. Four soil and cassava samples each obtained from each LGA were sun-dried and then oven-dried at 105˚C to constant weight. These samples were analyzed using gamma-ray spectroscopy at the Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife, Nigeria. Soil physicochemical parameters included particle size distribution, soil pH, soil organic carbon, soil organic matter, and exchangeable bases and they were determined using standard analytical methods. Radionuclide transfer factors (TFs) were computed as the ratio of activity concentration in cassava to that in soil. Mean activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K in cassava across the four LGAs ranged from 15.19 to 18.19 Bq/kg, 17.77 to 22.27 Bq/kg, and 581.21 to 637.72 Bq/kg respectively. Transfer factors for ²³⁸U, ²³²Th, and ⁴⁰K ranged from 0.91–1.08, 0.30–0.49, and 1.20–1.35 respectively. Pearson correlation analysis revealed statistically significant relationships between specific soil physicochemical properties and radionuclide transfer factors, notably between soil clay content and TFᵤ (r = 0.951, p < 0.05), and between ²³²Th in soil and TFₜₕ (r = 0.999, p < 0.01). The soils were predominantly sandy in texture with acidic pH (4.33–5.00), indicating moderate leaching conditions. These findings provide baseline radiological and pedological data for cassava-producing communities in Akwa Ibom State and contribute to the limited tropical ecosystem dataset on soil-to-plant radionuclide transfer.