Estimation of Radioactivity Content from Locally Minned Salt in Keana, Nasarawa State Nigeria

Locally mined salts that are sourced from rock and soils constitutes natural radionuclides of uranium (238U) and thorium (232Th) series, and the potassium (40K) radioactive isotope at a varying amounts. A total of 10 soil samples from different site of locally mined salt were collected and analysed using gamma ray spectrometer in order to determine the activity concentrations of the natural radionuclides. The mean activity concentrations determined for K-40, U -238, Th-232 were 1324.27 ± 68.91 Bq/kg, 147.43 ± 17.21 Bq/kg, 60.03 ± 3.56 Bq/kg which is above the worldwide weighted mean of 420 Bq/kg, 45 Bq/kg and 33 Bq/kg respectively, with the mean radium equivalent activity of 335.23 ± 27.61 Bq/kg which is below the upper limit of 370 Bq/kg, the external hazard index, the internal hazard index, the absorbed dose rate and the effective dose rate, Activity utilization index and Representative level index in the salt soil were evaluated. The results showed high gamma radiation absorbed dose and radiation hazard index, which does not present a better indications for human health in the study area.