PAULO FLAVIO DE MACEDO GOUVEA
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Artigo IPEN-doc 27878 Radiological characterization of peloids obtained by maturation with Águas de Lindóia, Poços de Caldas and Peruíbe waters2021 - TORRECILHA, J.K.; MARRICHI, J.M.O.; SOUZA, E.A.P.; GOUVEA, P.F.M.; ALVES, I.C.; SANTOS, A.; SILVA, P.S.C.One of the concerns about using mineral clay for therapy treatments is its radioactivity content due to natural radionuclides, normally, associated with the clays. This work proposes to characterize the natural radionuclides of the peloids obtained by the maturation process of mixing two different clays (gray and green) with different mineral medicinal waters from Águas de Lindóia (SP), Poços de Caldas (MG) and sea water from Peruíbe (SP). The gamma spectrometry showed that the gray and green bentonite peloids, all the activity concentrations of radionuclides are higher in gray ones, except 40K. The activity concentration varied from 84 to 156 Bq kg−1 (228Ra), 25 to 156 Bq kg−1 (228Th), 9 to 161 Bq kg−1 (226Ra), 39 to 256 Bq kg−1 (210Pb) and 162 to 1070 Bq kg−1 (40K). However, by calculating the absorbed dose rate in the worst scenario, this may not be a problem for topical application. Although the waters from Águas de Lindóia and Poços de Caldas are considered radioactive they have not caused a significant increase in radionuclide concentrations absorbed dose rate.Resumo IPEN-doc 24545 Chemical characterization of the clay deposit known as peruvian black mud2017 - ALVES, I.C.; GOUVEA, P.F.M.; SILVA, P.S.C.In Peruíbe city, state of São Paulo, the largest continuous natural deposit of clay in the world can be found, containing of a material popularly known as Peruíbe Black Mud (PBM). This deposit has 83 thousand tons with a depth of 75m, distributed in 5 hectares, making the municipality a tourist point. This sludge is characterized by large amounts of fine particles, high organic matter content, high sulfite reducing bacteria content and a consequent high ion reduction potential; it is used in psoriasis, peripheral dermatitis, acne and seborrhea treatments, as well as in myalgias, arthritis and non-rheumatic joint processes. Ten samples of the in natura mud were collected along the deposit, in depth ranging from 1 to 1.5m and also 6 samples that were matured with see water, with the objective of verifying the homogeneity of the chemical composition through the evaluation of its elemental content, for the physical-chemical characterization, measurements of pH, moisture, organic matter and loss on ignition were made. The elemental concentrations were determined by neutron activation analysis. In these measurements approximately 100mg of sample were irradiated together with certified reference materials, for a period of 8 hours under a neutron flux in the order of 1012 n cm2 s1. The activities were determined by gamma spectrometry using high-purity Ge detectors. Both, in natura and maturated samples presented similar coefficient of variation for most of the elements, with Ca, Co, Cr, Cs, Fe, La, Th and U having a coefficient of variation lower than 30%, the elements As, Sm, Tb, Zn and Zr presented a coefficient of variation between 30 and 60% and the elements K, Nd, Sb, Se, Tb and Yb presented the highest coefficients of variation, above 60%.