FERNANDA CAVALCANTE
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Artigo IPEN-doc 29139 Assessment of natural radioactivity in bottled mineral water from Brazil2022 - NISTI, M.B.; NERY, A.D.; SAUEIA, C.H.R.; CAVALCANTE, F.The approach taken in the WHO Guidelines for controlling radiological hazards in public water supplies has two stages. The first is an initial screening for gross alpha and beta activity to determine whether the activity concentrations are below levels at which no further action is required; and if these screening levels are exceeded, investigation of the concentration of individual radionuclides and comparison with specific guidance levels. Mineral water is obtained directly from natural sources or by extracting groundwater, it is characterized by the quantity of mineral salts, trace elements and other constituents. The bottled water industry is present in the major regions of the world, and the population consumption has increased every year in Brazil and world, also increasing new mineral water mining sites, so it is necessary to constantly check the amount of radioactivity in mineral water. The aim of this study is to quantify the concentration of the natural radionuclides in the bottled mineral water consumed in São Paulo city. The bottled mineral water samples were purchased in a supermarket in São Paulo, with 23 different brands. The determination of gross alpha and beta activity concentration in bottled mineral water by Liquid Scintillation Counting measurement was performed using a 1220 Quantulus™ Ultra Low-Level Liquid Scintillation Spectrometer. The natural radionuclides (226Ra, 228Ra, 210Pb and 40K) were measured by gamma spectrometry, using an HPGe detector. The results obtained in this study can be used for a database on bottled mineral water radioactivity from Brazil.Artigo IPEN-doc 28657 Reducing the risk for the biota by reusing a NORM residue2022 - NISTI, M.B.; CAVALCANTE, F.; SAUEIA, C.H.R.; MAZZILLI, B.P.All biota is exposed to natural radiation, the soil being the major source of radionuclides. Phosphogypsum (PG) is classified as a NORM residue of the phosphate fertilizer industry, often used in agriculture, as a soil conditioner. This residue is stored in stacks by the phosphate industries, potentially posing environmental risks. The aim of this study is to compare the risk for the terrestrial and aquatic biota arising from the storage of PG residue in the environment with that arising from its reuse as soil amendment. For this purpose, typical Brazilian soils amended with PG and PG itself were leached with distilled water. The concentration of natural radionuclides in the soil samples were used to evaluate the risk for terrestrial and aquatic biota, using the ERICA Tool. The results for terrestrial biota exposed to soils amended with phosphogypsum showed a risk reduction of about 85%, when compared to the exposure arising from phosphogypsum stacks. Considering the aquatic biota, the results showed a risk reduction of about 46% when comparing to radionuclide concentrations in leachates from phosphogypsum and from the soils amended with phosphogypsum. A new risk reduction assessment was performed to determine exclusively the contribution of the application of PG to the soil using the soil without PG, the risk reduction for terrestrial biota was of 99% and aquatic biota was a 74% reduction. Finally, it can be concluded that the addition of phosphogypsum in soils reduces the risk quotient related to the exposure of terrestrial and aquatic biota, showing that this is a safe practice.Artigo IPEN-doc 28187 Assessment of natural radioactivity in bottled mineral water from Brazil2021 - NISTI, M.B.; NERY, A.D.; SAUEIA, C.H.R.; CAVALCANTE, F.Tese IPEN-doc 23116 Avaliação da radioatividade natural e artificial em rações comerciais para animais domésticos2017 - CAVALCANTE, FERNANDAOs níveis de radioatividade natural do planeta e suas eventuais consequencias são objeto de estudo da radioproteção ambiental. Nos últimos anos, as agências internacionais ligadas à proteção radiológica têm debatido as práticas até então estipuladas, no que diz respeito à proteção da fauna e flora, cuja filosofia acreditava que as recomendações sugeridas para a proteção do homem asseguravam que outras espécies estariam também protegidas. Assim, são necessários estudos sobre as concentrações de atividade dos radionuclídeos dispersos no meio ambiente, assim como as doses absorvidas por organismos de diferentes ecossistemas, pela exposição interna e externa. O Brasil possui a segunda maior população de cães e gatos do mundo e produz anualmente mais de 2 milhões de toneladas de rações. O presente trabalho investigou os níveis de radioatividade presentes em rações comerciais para cães e gatos, por meio da espectrometria gama de alta resolução. Os resultados mostraram concentrações abaixo da MDA para radionuclídeos artificiais e baixas concentrações para radionuclídeos naturais, cujos valores variaram de 0,9 ± 0,3 Bq/kg a 5,1 ± 0,7 Bq/kg para o 226Ra, de 1,2 ± 0,4 Bq/kg a 11,1 ± 1,0 Bq/kg para o 232Th e de 156 ± 7 Bq/kg a 410 ± 19 Bq/kg para o 40K. Para verificar a composição de alguns minerais, foi empregada a técnica por EDXRF e, utilizando estatística multivariada, foi possível verificar as correlações entre os radionuclídeos e o conteúdo mineral encontrado. A boa correlação que foi observada entre as concentrações de 226Ra, 232Th e cálcio, pode estar associada ao uso de farinhas de carne e ossos na fabricação das rações. As doses internas para alguns órgãos foram inferidas pelo método de Monte Carlo, obtendo valores menores que 1 μGy/dia. Em síntese, os resultados mostraram que os níveis de atividade encontrados nas rações são baixos o suficiente para concluir que as marcas de ração canina avaliadas não fornecem riscos radiológicos para os animais que as consomem.