Contrasting radiological scenarios in waters from Campinas city, São Paulo state, Brazil

The initial screening of the gross alpha and gross beta radioactivity was done in six water samples collected at Campinas city, São Paulo State, Brazil, for evaluating if they are potable, taking into account the limiting values established in 2011 by the WHO (World Health Organization). Four of them provided from deep wells exploiting different aquifer systems occurring in that site. The same waters were analyzed for naturally occurring radionuclides of the U-decay series (Po-210, Pb-210, Rn-222, Ra-226, U-234, and U-238) and the Th-decay series (Ra-228), whose activity concentrations were also compared with the WHO guidelines. Conversion factors allowed calculation of the radiation dose associated with the annual ingestion of these radionuclides in 2 L of drinking water per day, and comparison with the WHO limit of 0.1 mSv/yr. Finally, both datasets (gross alpha/beta and CED-Committed Effective Dose) were compared to provide a scenario of the quality of those water resources, considering the radiological aspects.