Evaluation of radionuclides and decay simulation in a terrestrial environment for health risk assessment

This study is to assess the natural radioactivity level in soil samples in communities bordering the Tano Basin in Ghana. The radioactivity concentration of ²³⁸U, ²³²Th and ⁴⁰K have been determined using γ-ray spectrometry, moreover, the absorbed dose rates and annual effective dose were calculated. MATLAB R2013 script was written to simulate the decay of the radionuclides ²³⁸U, ²³²Th and ⁴⁰K using their respective half-lives. This is to determine the future impact of natural radionuclides and estimate future anthropogenic inputs. The level ²³⁸U, ²³²Th, and ⁴⁰K ranged from (1.60 to 21.3), (2.78 to 32.2) and (111 to 528) with average values of be 8.65 Bqkg^-1, 12.5 Bqkg^-1 and 214 Bqkg^-1 respectively in soil. The activity concentrations were lower than United Nations Scientific Committee on the Effects of Atomic Radiation guidelines for ²³⁸U, ²³²Th and ⁴⁰K. The absorbed dose rates and annual effective dose were found to be in range of 7.79 to 37.8 nGy h^-1 and 9.56E + 00 to 4.64E + 01 μSvy^-1 respectively. The overall annual effective dose was lower than the allowable limit of 1mSvy^-1 set by International Commission on Radiological Protection^. H_ex, H_in and excess lifetime cancer risk (ELCR) were calculated and found to be within internationally recommended values.