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

摘要

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 29.144.4.2 Bqkg~(-1), with an average of 23.40 Bqkg~(-1) for (~(238)U - ~(226)Ra), 10.935.43 Bqkg~(-1) to 21.522.16 Bqkg~(-1) with an average of 16.50Bqkg~(-1) for ~(232)Th, and 291.7815.50 Bqkg~(-1) to 338.603.922 Bqkg~(-1) with an average of 314.11 Bqkg~(-1) for ~(40)K. 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 ~(238)U, ~(232)Th and ~(40)K 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.