Assessment of Background Ionizing Radiation and Radiological Health Risks in Federal Government Girls’ College, Imiringi, Nigeria

Abstract

Ionizing radiation poses health risks when exposure surpasses certain thresholds for humans. In the vicinity of Federal Government College Imiringi, crude oil activities potentially impact levels of naturally occurring radioactive materials. Thus, it's essential to evaluate potential impacts on students. Consequently, an assessment was conducted involving in-situ measurement of terrestrial gamma radiation and calculation of radiological health risks. This assessment utilized a well-calibrated RadMonitor-200 and established radiological equations. The study area was partitioned into three zones (Zone A, Zone B, and Zone C). Thirty sampling points were selected, with ten in each zone. Background ionizing radiation (BIR) results across the zones ranged from 0.011 to 0.015 mRhr-1, 0.008 to 0.21 mRhr-1, and 0.011 to 0.19 mRhr-1. Mean values were 0.015±0.002 mRhr-1, 0.017±0.003 mRhr-1, and 0.015±0.002 mRhr-1 for Zone A, Zone B, and Zone C respectively, with an overall mean of 0.017 mRhr-1. This suggests a slight exceedance of the recommended safe BIR value of 0.013 mRhr-1.The mean absorbed dose in Zones A, B, and C were 126.15±0.003, 147.03±0.002, and 126.15±0.002 nGyhr-1 respectively. The annual effective dose equivalent (AEDE) remained below the permissible safe limit of 1.0 mSvyr-1. Excess lifetime cancer risk (ELCR) ranged from 0.57 x10-3 to 0.89 x10-3, 0.49x10-3 to 0.94x10-3, and 0.57x10-3 to 0.85 x10-3 with mean values of 0.70 x10-3±0.001, 0.78 x10-3±0.001, and 0.71 x10-3 ±0.001 in Zones A, B, and C respectively, which were above 0.29x10-3. However, these elevations do not warrant the classification of the area as radiologically unsafe. Nevertheless, regular monitoring is advisable, particularly due to the observation of a potential methane gas emission within the college premises. The findings of this research should serve as baseline data for future spectrometry analyses of soil, borehole, and surface waters in the college's vicinity.