Assessment of radiological parameters of soil in Kogi State, Nigeria

The natural radioactivity levels of soil samples collected from four local government areas in Kogi State, Nigeria were measured using a hyper-pure germanium detector, and the radiological hazard parameters associated with them were estimated. The measured concentration ranged from 7.82 +/- 0.63 to 82.22 +/- 1.99Bq kg(-1) for U-238, 11.05 +/- 1.10 to 114.86 +/- 4.72Bq kg(-1) for Th-232, and 3.38 +/- 0.50 to 1272.20 +/- 23.36Bq kg(-1) for K-40. Omala local government was found to have the highest concentrations of U-238 (44.31Bq kg(-1)) and Th-232 (52.13Bq kg(-1)), while Ajaokuta has the highest concentration of K-40 (711.72Bq kg(-1)). The lowest activity concentrations of U-238 and Th-232 were measured from soil samples collected from Ankpa local government area and K-40 from Dekina local government area. It was noted that the activity concentrations of K-40 were generally low for all the areas investigated except for Ajaokuta areas. The radium equivalents calculated for all the locations were observed to be lower than the radiation protection regulatory body reference value of 370Bq kg(-1). The radiological parameters estimated for most of the locations compared well with world average values, except for Odogba-okaba, Salem University, Forest, Nepa, Gerugu, Niger Bridge, Igaliwu, Ijeke-ogane, Bagana, and Abegikolo villages, whose values exceeded the recommended limit. This may suggest that those living or working in these areas may be exposed to higher radiation burden from the natural radionuclides.