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 U-238, Th-232 and K-40 have been determined using gamma-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 U-238, Th-232 and K-40 using their respective half-lives. This is to determine the future impact of natural radionuclides and estimate future anthropogenic inputs. The level U-238, Th-232, and K-40 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 U-238, Th-232 and K-40. 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 mu Svy(-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.