Evaluation of the influence of soil types on the activity concentration of natural radionuclides in soil of Katsina State, Nigeria

This study evaluated the influence of soil type on the activity concentrations of natural radionuclides and the potential radiological risk in soils of southern Katsina, Nigeria. The measured activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th in soil samples ranged between 61.46 and 709.93 Bq/kg, 5.55 and 129.78 Bq/kg, 14.98 and 474.27 Bq/kg, respectively. Radiological hazard parameters, including the absorbed dose (D_R), outdoor and indoor annual effective dose (OAED and IAED), and internal and external hazard indices (H_in and H_ex) were evaluated to determine the potential radiological risk. The mean values for D_R, OAED, IAED, H_in, and H_ex were 82.84 nGy/h, 97.34 µSv/y, 389.44 µSv/y, 0.56, and 0.48, respectively. Despite the average absorbed dose across the five soil types surpassing global average values, the findings from the mean radiological risk parameters for various soil types (including OAED, IAED, H_in, and H_ex) suggest minimal radiation risk to biological tissue from exposure. This research indicates an irregularity in the radionuclide concentration within the soil of the examined area, yet implies that the soil may not present an immediate health threat to humans.