Natural Radioactivity Concentration and Radiological Evaluation in Soil Samples Around Dangote Cement Factory Ibese, Ogun State, Nigeria

Olatunji Kehinde Olanipekun,Bamidele Lateef

doi:10.11648/j.ns.20200502.12

Abstract

Background: Natural-occurring radioactive materials (NORMs) provide significant sources of human exposure to ionizing radiation but in certain cases, anthropogenic activities, like mining, have produced wastes that contain radiation above background levels in the environment, a situation that is of great concern for radiation protection. Around Dangote cement factory both mining and production have been on-going for some years, therefore there is need to evaluate the extent of the possible risk of the radionuclides to the health of the population in this study area. Measurements of radioactivity concentrations were carried out around Dangote Cement Factory Ibese. Samples of surface soil were measured using gamma-ray spectroscopy Nal (TI) scintillation detector. Results: Measurements showed that activity concentrations ranged from 18.33+ 1.91 Bqkg-1 to 29.14±4.4.2 Bqkg-1, with an average of 23.40 Bqkg-1 for (238U - 226Ra), 10.93±5.43 Bqkg-1 to 21.52±2.16 Bqkg-1 with an average of 16.50Bqkg-1 for 232Th, and 291.78±15.50 Bqkg-1 to 338.60±3.922 Bqkg-1 with an average of 314.11 Bqkg-1 for 40K. Similarly, the absorbed dose ranged from 28.63nGy/h to 38.24nGy/h with an average of 33.14nGy/h. The calculated annual effective dose ranged from 0.035mSv/y to 0.047mSv/y with an average of 0.040mSv/y. Conclusions: The average value of Radioactivity concentrations obtained for 238U, 232Th and 40K are lower than the corresponding global values reported in UNSCEAR publication. The calculated absorbed dose and annual effective dose values are also less than the recommended safe levels.

Highlights

Man since formation of the earth is exposed to many diverse sources of radiations
Gamma radiations emitted from Natural Occurring Radioactive Materials (NORMS) such as uranium (238U), thorium (232Th), and potassium (40k) are generally known as terrestrial background radiation and is the main external of irradiation of the human body
External annual effective dose and absorbed dose rate of are soil samples shown in the table 1

Summary

Introduction

Man since formation of the earth is exposed to many diverse sources of radiations These sources may be natural or as a result of human activities. Gamma radiations emitted from Natural Occurring Radioactive Materials (NORMS) such as uranium (238U), thorium (232Th), and potassium (40k) are generally known as terrestrial background radiation and is the main external of irradiation of the human body. Radiation from soil environment is one of the main source of exposure to humans it is important to know the distribution of gamma radiation from radionuclide’s such as 40K and from 238U. Natural-occurring radioactive materials (NORMs) provide significant sources of human exposure to ionizing radiation but in certain cases, anthropogenic activities, like mining, have produced wastes that contain radiation above background levels in the environment, a situation that is of great concern for radiation protection. The calculated absorbed dose and annual effective dose values are less than the recommended safe levels

Methods

Results

Conclusion