Assessment by portable gamma spectrometry of external gamma radiation hazard due to granitic materials and indoor space typology

Abstract

Building materials can contribute to ionizing radiation hazards due to their variable content in radioactive isotopes. Uranium, thorium, and potassium radioisotopes are present in various building materials due to their presence in raw materials: minerals and rocks. Among natural building materials, granite is one of those deserving more attention in terms of radioactive hazards. Granites are commonly used in historical buildings of NW Portugal and NW Spain, due to the geological characteristics of these areas. However, radioactive isotopes are present in variable proportions in granites, and thus, in relation to other potential building materials, granites might present a higher radiological hazard. This work discusses multivariate analysis results obtained by spectrometry of a portable range in indoor spaces, presenting different proportions of granite used as a building material in order to evaluate a typology proposed for assessing gamma radiation hazards.