Natural radionuclides and radiological risk assessment of granite mining field in Asa, North-central Nigeria

In this study, a well calibrated Super-Spec (RS-125) gamma spectrometer was used to measure the activity concentrations of K-40, U-238, Th-232 and gamma doses rate at 1 m above the ground level over a granite mining field in Asa, Kwara State, North-central Nigeria. Measurements were carried out in 50 randomly selected sample points. The overall mean activity concentrations of K-40, U-238, Th-232 and gamma dose are 570.91, 42.86,18.15 Bqkg(-1), and 60.11 nGyh(-1) respectively. The results of the activity concentrations were used to estimate the corresponding radiation hazard parameters to assess the suitability of the granite for building and construction purposes. The data in this study could serve as the baseline radiological data of the region for future references. Activity concentrations of K-40, U-238, Th-232 and gamma doses were measured over a granite mining field in Asa. The total mean activity concentrations of the radioisotopes and gamma dose are 570.91, 42.86,18.15 Bqkg(-1), and 60.11 nGyh(-1) respectively. The radiological hazards are higher than the recommended permissible limits. (C) 2019 The Author(s). Published by Elsevier B.V.