Gamma radiation in rocks used as building materials: The Braga granite (Nw Portugal)
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Abstract
Granite can be a rock with significative radioactivity levels due to its content in radioisotopes of K, U e Th. The Braga granite has been extensively used from the past in historical buildings of this city in North Portugal. A gamma radiation assessment has been made in quarry samples of the Braga granite with different weathering degree, in order to assess radiation risks in historical buildings, derived from their content in radionuclides. The specific activities of radioisotopes in 238U and 232Th decay chains and radioactive 40K were measured by gamma spectrometry on samples with different weathering degree. The results were used to calculate the gamma building index (Iγ; EU technical guidance RP112) and other indices to estimate the radiological hazard of the rock as building material. Specific activities are above world averages and all the samples have Iγ >1 (the threshold that implies specific studies for building materials). This result can be especially relevant for historical building where this granite is used as bulk material.
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AIEA. (2003) Internatinal Atomic Energy Agency: Guidelines for radioelement mapping using gamma ray spectrometry data. IAEA-TECDOC-1363, Vienna.
Amaral, E. Alves J., Carreiro J. (1992) Doses to the Portuguese population die to natural gamma radiation. Radiation protection dosimetry: 541-543.
Amaral, E.M. (2000) Natural gamma radiation in air versus soil nature in Portugal. Procedings IRPA, 10, Hirosima, P-1, P-12.
Arafa, W. (2004) Specific activity and hazards of granite samples collected from the Eastern Desert of Egypt. Journal of Environmental Radioactivity 75, 315-327.
Beretka, J., Mathew, P.J. (1985) Natural radioactivity of Australian building materials, industrial wastes and by-products. Health Pysics, 48, 87-95.
CUE – Consejo de la Union Europea (2013) Directiva 2013/59/EURATOM del Consejo de 5 de diciembre de 2013 por la que se establecen normas de seguridad básicas para la protección contra los peligros derivados de la exposición a radiaciones ionizantes, y se derogan las Directivas 89/618/Euratom, 90/641/Euratom, 96/29/Euratom, 97/43/Euratom y 2003/122/Euratom
Dias, G., Sirngesl, P. P., Ferreira, N., Leterrier, J. (2002) Mantle and Crustal Sources in the Genesis of LateHercynianGranitoids (NW Portugal ): Geochemical and Sr-Nd Isotopic Constraints. Gondwana Research, 287-305.
Dickson, B.L., Scott, K.M. (1997) Interpretation of aerial gamma-rays surveys– adding the geochemical factors. Australia. AGSO, Journal of Australian Geology and Geophysics, 17(2), 187-200.
E.C. - European Comission (1999) Radiation protection 112 Radiological Protection Principles concerning the Natural Radioactivity of Building Materials. Luxembourg.
Gascoyne, M. (1992) Geochemistry of the actinides and their daughters. In: Ivanovich, M, Harmon, R.S., (eds.). Uranium series disequilibrium, aplications to Earth, marine and environmental sciences. Clarendon Press, Oxford, 34-61.
Heier, K.S. (1975) The movement of uranium Turing higher grade metamorphic processes. Theoretical and practical aspects of uranium geology. Philosophical Transactions of the Royan Society of London, Series A, Mathematical and Physical Sciences, 291(1381), 413-421.
Kovler, K. (2009) Radiological constraints of using building materials and industrial by-products in construction. Construction and Building Materials, 23(1), 246-253. Haifa, Israel.
Markkanen, M. (1995) Radiation Dose Assessments for Materials with elevated Natural Radioactivity. STUK-BSTO 32, Finnish Center for Radiation and Nuclear Safety. Helsinki.
Moharram B., Suliman M., Zarhan N., Shennawy S., El Sayed A. (2012) External exposure doses due to gamma emitting natural radionuclides in some Egyptian building materials. Applied Radiation and Isotopes 2011; 70, 241-248.
Moura, C.L., Artur, A.C., Bonotto, D.M., Guedes, S., Martinelli, C.D. (2011) Natural radioactivity and radon exhalation rate in Brazilian igneous Rocks. Applied Radiation and Isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine, 69(7), 1094-1099.
Righi, S., Bruzzi, L. (2006) Natural radioactivity and radon exhalation in building materials used in Itallian dwellings. Jorunal of Environmental Radioactivity, 88, 158-170.
Risica, S., Bolzan, C., Nuccetelli, C. (2001) Radioactivity in building materials: room model analysis and experimental methods. The Science of the total environment, 272(1-3), 119-126.
Rosen, D. (2014) Radiation from mansonry products – Dose assessment and classifications of emited gamma radiation. 9th International mansonry conference, Guimaraes, Portugal.
Sroor, A., Afifi, S.Y., Abdel-Haleem, A.S., Salman, A.B., Abdel-Sammad, M. (2002) Environmental pollutant isotope measurements and natural radioactivity assessment ofr North Tushki area, Southwestern Egypt. Applied Radiation Isotopes, 57 (3), 427-436.
Sonkawadea, R.G., Kantb, K., Muralithara, S., Kumara, R., Ramola, R.C., (2008) Natural radioactivity in common building construction and radiation shielding materials.Atmospheric Environment 42, 2254-2259.
UNSCEAR - United Nations Scientific Committee on the Effects of Atomic Radiation. 1988. New York.
UNSCEAR - United Nations Scientific Committee on the Effects of Atomic Radiation. 2000. New York.