DETERMINATION OF BACKGROUND IONIZATION RADIATION (BIR) LEVELS IN SOME SELECTED FARMS IN DELTA STATE, NIGERIA

Abstract

In-situ background ionization radiation (BIR) level in 25 farms spread across the local government areas of Delta State, Nigeria was measured using a FOS 2011+ radiation metre, with reading accuracy of 0.001.  The precise positions of the locations were determined using a geographical positioning device (GPS). Results show that the BIR levels range from 0.008 – 0.014 mRh-1, with a mean of 0.009 ± 0.0004 mRh-1.  Three (12 %) of the studied farm lands have radiation levels higher than the 0.013 mRh-1recommended by the ICRP. The mean values of the radiation health parameters obtained are 7.19 mGyy-1, 3.78 mSvy-1 and 12.46 x 10-3 for dose rate, annual equivalent dose and excess life-time cancer risk, each of which is higher than the corresponding internationally recommended value of 1.0 mGy-1, 1. 0 mSvy-1 and 0.29 x 10-3 respectively. It is suggested that there should be an immediate monitoring and regulatory action by the relevant radiation protection authorities.