Contribution of fibre-cement building material to environmental radioactivity
In this work, the natural radionuclide contents of some fibre-cement building material widely used in Nigeria were measured by means of gamma-ray spectrometry using an HPGe detector. A total of 20 samples obtained from five batches of the product were analysed. The mean values of 226Ra, 232Th and 40K concentrations determined are 9.40±3.29 Bq kg-1, 6.01±2.29 Bq kg-1 and 27.86±3.20 Bq kg-1 respectively. These values are lower than the permissible global values of 52.2 Bq kg-1, 41.0 Bq kg-1 and 230.0 respectively by UNSCEAR. On the basis of the hazard indices an external dose criterion index of 0.071 and internal hazard index of 0.08, were obtained for the material. The results of this work will provide valuable data on the utilization of this type of material for construction of buildings.
Keywords: Radionuclide, gamma spectrometry, building material, fibre-cement, hazard indices.