ABSTRACT
ABSTRACT: Granite is one of the most radioactive rocks due mainly to their content in K, U e Th. In order to assess radiation risks in historical buildings, a gamma radiation assessment has been made in quarry samples of the Braga granite with different weathering degree. Using gamma spectrometry, the specific activities of U and Th, decay chains and radioactive K, were measured. The specific activities of radionuclides were used to calculate the gamma building index (Iγ) of the EU technical guidance (RP112) for regulatory control of building materials, and to estimate some radiological hazardous parameters such as: the average radium equivalent activity (Raeq), Annual Gonadal Equivalent Dose (AGED), the absorbed dose and the annual effective doses. All the samples exceed the Iγ value of 1 and the indoor air annual effective dose rate in excess due to buildings materials can be higher than 1 mSv y−1 in the more weathering samples.
