~(226)Ra, ~(228)Ra and ~(210)Pb DETERMINATION IN SURFACE WATER AND GROUDWATER BY LIQUID SCINTILLATION COUNTING

摘要

The municipalities of Brumadinho and Nova Lima are located in the metropolitan region of Belo Horizonte city, in the State of Minas Gerais. These two sites are important due to being located inside an Environmental Protection Area inserted in the Iron Quadrangle. In addition to the mineral wealth, the region has geological features that include quartz conglomerates associated with uranium and a significant groundwater potential exhibiting quite peculiar and complex hydrogeological features, such as the quartzite aquifer itself. Nuclear techniques applied to hydrology, such as Liquid Scintillation Counting technique (LSC), make possible the evaluation of natural radioactivity in surface water and groundwater. The objectives of this study were the determination of the activities of the long half-life radionuclides of the uranium and thorium series, such as ~(226)Ra, ~(228)Ra and ~(210)Pb, and provide an effective methodology to define if the direct consumption of these waters can cause risk to health due to its radioactivity. The results were compared with the recommendations of the Ministry of Health.