Evaluation of radiological hazard parameters in building materials used in a caserural area of Ghana

摘要

The measurement of specific activity due to Naturally Occurring Radioactive Materials (NORM) has been carried out in soil and Portland cement and its products available in two rural communities near Aflao, Ghana. The gamma spectra of the collected samples were obtained using HPGe detector and analyzed for the presence of 226Ra, 232Th and 40K. In addition, the radon emanation coefficient and the corresponding mass exhalation rate of the samples were determined using the same instrumentation. The aim of the study was to find out whether the shift from the use of ingenuous soil to Portland cement in the construction of dwellings is more radiologically safe for inhabitants in the study area. Radiological parameters such as the radon emanation coefficient, the radon mass exhalation rate, the radium equivalent activity, the external and internal hazard indices, the indoor absorbed dose rate, and the annual effective dose were determined to assess the potential radiation hazards associated with the samples. The results were compared with reported data from other countries and safety guidelines from international recommendations. The study found out that the radium equivalent activity of the Portland cement and the raw materials of which it was composed was higher than reported data from other different countries whilst the soil values were lower compared to other published values. The variations and the large spread in data are a reflection of different geological origins of the building materials. However, the radiological hazard parameters assessed in the building materials under the current study were all found to be well below the acceptable limits of international guidelines. Therefore, it was concluded that the use of these materials in construction of dwellings is considered safe for inhabitants of the study area.