Assessment of ionizing radiation exposure levels and associated health risk in some selected solid mineral mining sites Edo-North, Nigeria

Abstract

Ionizing radiation exposure rate and its associated health risks were assessed using Digilert 200 and Rados Radiation Monitoring Meter, integrated with Geographical Positioning System (Garmin GPSMAP 76S) of some selected solid mineral mining sites across Edo-North Nigeria. The mean exposure rates show some characteristic range of 0.010±0.005 𝑚𝑅ℎ𝑟−1 to 0.027 𝑚𝑅ℎ𝑟 −1 across the entire study. The obtained mean exposures rates at all the mining pits were higher than the ICRP standard limit of 0.013 𝑚𝑅ℎ𝑟 −1 , except at freedom limestonesmining pit where we recorded 0.010 mRh-1. It was also observed that limestones mining sites exhibited low exposure rate while granite mining sites exhibited high exposure rate. The computed equivalent dose rate ranges from 1.049 mSvy-1 to 2.287 mSvy-1 , which is well above the recommended permissible limit of 1.0 mSvy-1 for the general public. 91.7% of the mining sites recorded higher absorbed dose rate but the mean AEDE recorded across the entire study area are below the ICRP standard. The average excess lifetime cancer risk shows variation from 0.472 x 10-3 to 1.27 x 10-3 . . By this result, the probability of contacting cancer due to radiation exposure is higher in places like Cinoma pit, Cetraco pit, Niger-Cat pit, Jigom pit, Oaries pit and Petra-Quarries pit.
 Keywords: Assessment, Mining pits, Background, Exposure, lifetime cancer risk