Radium-228 as an indicator of thorium-232 presence in a soil in Pernambuco, Brazil.

Radiometric measurements were taken in a small area of Pernambuco, Brazil, with the objective of monitoring the radium of the soil. For this, 78 soil samples were collected. The gamma analyses of the samples were carried out using HPGe. The values obtained for the (226)Ra varied from 14 to 367 Bqkg(-1) and for the (228)Ra from 73 to 429 Bqkg(-1). The ratio (228)Ra/(226)Ra varied from 1.0 to 7.0. Therefore, it is an indicator of an additional radioactivity source in this soil, maybe (232)Th, which will be further investigated in future studies.