Assessment of radioactivity in the drinking water of state of Goias, Brazil

The demand for drinking water is supplied by surface and underground sources such as rivers and streams. However, there is an increasing worldwide concern about the quality of drinking water. As a result, it is a major goal of governments throughout the world to ensure that water is safe for human consumption through the control of microorganisms, chemicals and radioactive substances. The Brazilian Ministry of Health has issued guidelines designed to protect the quality of drinking water. The use of screening measurements for gross alpha and beta radioactivity is recommend since it maximizes cost-effectiveness of assessing the individual radionuclide content of drinking water. In order to do so tests were carried out to determine of gross alpha and beta radioactivity concentrations in drinking water samples from 44 water supply wells within the State of Goias. The technique used was thermal preconcentration and radiometric determination by liquid scintillation spectrometry. The concentrations for gross alpha ranged from < LD at 0.19 ± 0.05 Bq/L. As for gross beta they ranged from < LD at 0.2 ± 0.1 Bq/L. The results were also related with the geological and hydrological data. (author)