Dose de exposição radiométrica de granitos do estado de Rondônia, Brasil

• Autor(a) principal: Bonotto, Daniel Marcos [UNESP]
• Data de Publicação: 2009
• Outros Autores: Leite Júnior, Washington Barbosa [UNESP], Payolla, Bruno Leonelo, Bettencourt, Jorge da Silva, da Silveira, Ene Glória
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S0102-261X2009000300003; http://hdl.handle.net/11449/71056
• topic: Gamma exposure rate; Granites; Radioactivity; concentration (composition); dose-response relationship; gamma ray radiation; granite; mineral; pollution exposure; potassium; radioactivity; rock; statistical analysis

This work evaluated the activity concentration of the radioelements K, eU and eTh in samples of granites from Rondônia State, Brazil. The statistical analysis of the data indicated that they fit lognormal distributions. The modal values correspond to about 11% for K, 29 ppm for eU and 85 ppm for eTh. Directsignificant correlations were found among the concentrations of the three radioelements, i.e. r = 0.71 (between K and eU), r = 0.72 (between K and eTh), andr = 0.72 (between eU and eTh), suggesting congruency of their accumulation in minerals occurring in the rocks analyzed. The activity concentration data allowed estimate the absorbed dose rate in air at 1 m above the ground, which also fits a lognormal distribution characterized by a mode of 2.7 mSv/y that is slightly higher than the average worldwide exposure of 2.4 mSv/y. The results obtained also allowed evaluate if the granites analyzed are radiometrically suitable as building and ornamental materials. © 2009 Sociedade Brasileira de Geofísica.