Radiological Hazard Assessment of Sharp-Sand from Ilorin-East, Kwara State, Nigeria

Abstract

Measurement of activity concentration of primordial radionuclides 40K, 232Th, 238U and the corresponding gamma dose rate over a major sharp-sand field in Ilorin, Nigeria, was carried out using Super Spec RS125 gamma ray spectrometer. The RS125 gamma spectrometer gives in-situ measurement of radioactivity concentration. Measurements were taken in 50 locations. The peak values of the measured activity concentrations of 40K, 238U, 232Th, the dose rate (D) and the resulting annual effective dose (AED) are 688.60, 48.17, 30.86 Bqkg−1, 49.50 nGyh−1 and 0.06 mSvy−1 respectively, while their corresponding lowest values are 31.30, 1.24, 0.41 Bqkg−1, 4.70 nGyh−1, and 0.01 mSvy−1 respectively. The estimated mean values of 40K, 232Th, 238U, the gamma dose rate (D) and AED are 454.48, 13.52, 11.63 Bqkg−1, 32.96 nGyh−1 and 0.04 mSvy−1 respectively. Consequently, the mean values of the measured radionuclides and the hazard parameters i.e. dose rate and annual effective dose are within the permissible levels. This follows that the risk of radiation exposure for this location is comparatively less, but the general public may not be safe from exposure to indoor ionizing radiation since no amount of radiation is safe for stochastic effects.