Radiation Risk Assessment of Soil in Idomi, Cross River State, Nigeria

N. O. Chiaghanam, C. C. Nzotta, L. B. Enweani

Abstract


In this thesis work, the radiation risk from soil samples in Idomi community located at Yakurr Local Government Area of Cross River State, Nigeria was studied. This was because of an earlier study that revealed the presence of high radioactivity in the area. This study aim to determine the background radiation levels, estimate their effective dose, the mean activity concentrations of the radionuclide and the radiological implications of the radioactivity levels in Idomi. Thirty (30) soil samples were collected and analyzed. The baseline average annual outdoor effective dose, mean activity concentration, gamma absorbed dose and radiological hazard index were studied. Results from this study indicate that three (3) radionuclide namely 40K, 238U and 232Th were present in the soil samples analyzed.  The mean activity concentrations of 40K, 238U and 232Th in the soil samples were 506.13±9.30, 41.14±3.59 and 84.52±20.88 Bqkg-1 respectively.  The calculated mean external and internal hazard index was 0.62 and 0.71 respectively. The calculated mean gamma index was 0.86. The Raeq in the soil samples was 227.34 Bqkg-1. The calculated absorbed gamma dose from the sample was 110.31nGy-1 and a mean annual outdoor effective dose of 1.35mSvy-1.  Compared with global average values of 10-200nGyh-1, 2.4 mSvy-1and Raeq of 370BqKg-1 they can be said to be within the normal range. From this study, the chances of occurrence of health effects from exposure to natural terrestrial gamma radiation in Idomi can be said to be low.  This may be possible if the baseline levels obtained from this study can be kept constant by keeping the environment free of radioactive pollution.


Keywords


Radiation, Risk, Assessment, Soil, Activity

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DOI: https://doi.org/10.24203/ajas.v7i1.5593

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