Mobility indices and doses from210Po and210Pb activity concentrations data in Brazilian spas groundwaters.
210Po and210Pb activity concentrations in spas groundwaters occurring at São Paulo (SP) and Minas Gerais (MG) states, Brazil, have been reported in this paper with a dual purpose: to compare different indices for evaluating the radionuclides mobility into waters and to evaluate the drinking water quality from dose calculations. The waters (75 sampling points) are extensively used for drinking in public places, bottling and bathing purposes, among other. The samples were taken from springs and wells drilled at different aquifer systems inserted in Paraná and Southeastern Shield hydrogeological provinces. The WHO guideline reference value for210Pb and210Po of 0.1 Bq/L in drinking water was not reached for210Pb but the210Po levels were equal or above it in four spas groundwaters from MG State. The maximum WHO guidance dose level of 0.1 mSv/yr was also reached or surpassed in them. The210Pb "mobility index" taking into account the ratio of the weight of the dissolved210Pb per unit volume of solution to its weight per unit weight of the rock matrix yielded values in the range of 0.01-5.2 kg/m3. Another "mobility index" (Preference Ratio) expressing the ratio of210Pb and238U in the waters divided by the ratio of210Pb and238U in the rock matrices provided values between 0.004 and 7994. The210Pb/238U activity ratios of some spas groundwaters suggested preferential238U transport relative to210Pb into the liquid phase, whereas the ratio of the210Pb to238U mobility indices indicated the opposite. Such finding showed a better usefulness of the mobility indices for evaluating processes affecting the radionuclides release into the liquid phase during the water/rock interactions.
Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Câmpus de Rio Claro, Av. 24-A No.1515, C.P. 178, CEP 13506-900, Rio Claro, São Paulo, Brazil. Electronic address: danielmarcosbonotto@gmail.com.
Daniel Marcos
DM
Bonotto
Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista (UNESP), Câmpus de Rio Claro, Av. 24-A No.1515, C.P. 178, CEP 13506-900, Rio Claro, São Paulo, Brazil.
Ana Maria Marinello Assis de
AMMA
Oliveira
D001938:Brazil; D060587:Groundwater / Q000737:chemistry*; D045482:Hot Springs / Q000737:chemistry*; D007856:Lead Radioisotopes / Q000032:analysis*; D011059:Polonium / Q000032:analysis*; D011834:Radiation Monitoring; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D014881:Water Supply
D007856:Lead Radioisotopes; D014875:Water Pollutants, Radioactive; D011059:Polonium
(210)Po and (210)Pb; Radionuclides mobility; Southeastern Brazil; Spas groundwaters