Estimation of Absorbed Dose Rate and Collective Effective Dose Equivalent Due to Gamma Radiation from Selected Radionuclides in Soil in Ondo and Ekiti State, South-Western Nigeria

Abstract

The concentrations of natural radionuclides, namely 40 K, 238 U and 232 Th, in surface soils in Ondo and Ekiti States, south-western Nigeria have been measured using a very sensitive gamma ray spectroscopic system consisting of a 760 mm × 760 mm NaI(TI) scintillation detector coupled to a Canberra Series 10 Plus multichannel analyser. The mean absorbed dose rate, annual effective dose equivalent and the collective effective dose equivalent in these states have been estimated from the measured concentrations of the radionuclides, which are 0.015 ± 0.008 μGy.h -1 , 18.4 μSv.y -1 and 73.6 man.Sv.y -1 respectively.