A method for evaluating 228Ra in environmental matrices and its use at Poços de Caldas plateau, Brazil.

This work describes a methodology developed for performing the extraction, detection and quantification of 228Ra in waters, suspended solids and sediments. The technique proved to be useful for analyzing samples from the hydrological environment of Morro do Ferro, Poços de Caldas plateau, Brazil. The 228Ra activity in underground waters of 5 boreholes drilled in the area varied from 0.02 up to 14.5 Bq/l, whereas for the surficial waters the variation was from 0.04 to 0.51 Bq/l; for the suspended solids, the values ranged from 1.5 up to 419 Bq/g, whereas it was possible to find a value of 2.04Bq/g for the sediments. These results show the applicability of the method for characterizing different matrices of environmental interest.