Outdoor Background Radiation Level and Radiological Hazards Assessment in Lafia Metropolis, Nasarawa State, Nigeria
List of Authors
  • Idris Mohammed Mustapha , Rahmat Sadiq Tukur

Keyword
  • Radiation, radiological, assessment

Abstract
  • In this study, the assessment of the outdoor Background Radiation levels in Lafia Metropolis, Nasarawa State, Nigeria has been conducted. An in-situ measurement of outdoor background exposure rate count per minute for 20 locations was done using a well calibrated portable halogen-quenched Geiger Muller (GM) detector (Inspector alert Nuclear radiation monitor SN:3544) at an elevation of 1.0m above ground level with a geographical positioning system(GPS) for geographical location. Using an established radiological relations, the radiological health hazards and radiation effective doses to different body organs were evaluated using the measured outdoor background exposure rates. The values obtained were compared with recommended permissible limits to ascertain the radiological hazard status of the environment. The mean values of the outdoor background exposure levels (0.021 mRh-1), absorbed dose rates (184.875 nGyh-1) and excess lifetime cancer risk (0.794×10-3) are higher than their recommended safe limits of 0.013 mRh-1, 84.0 nGyh-1, 0.29×10-3respectively as recommended by UNSCEAR and ICRP. The mean annual effective dose equivalent (AEDE) (0.227 mSvy-1) is below recommended permissible limits of 1.00 mSvy-1 for general public exposure and also the effective doses to different body organs are all below the recommended limits of 1.0 mSvy-1. Generally, the study shows that Lafia Metroplis is relatively safe radiologically with little contamination which could be attributed to the geological formation and partly due to human activity in the area. However, the contamination will not pose any immediate radiological health effect on resident of the area but there is tendency for long –term health hazards in the future such as cancer due to doses accumulated.

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