ANDRESSA DAMACENO NERY
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Artigo IPEN-doc 29129 Determination of natural radionuclides (Ra-226, Po-210, Ra-228 and K-40) and Cs-137 in fish consumed in the city of São Paulo2022 - NERY, A.D.; NISTI, M.B.; SAUEIA, C.H.R.; MAZZILLI, B.P.The aim of the study was to determine the activity concentration of the natural radionuclides (226Ra, 210Po, 228Ra and 40K) and artificial radionuclide 137Cs in the muscle of the marine fish species most consumed in the city of São Paulo and to evaluate the annual effective dose due to the consumption of the fish. Samples were collected in the supermarket chain Extra and Carrefour and in the distribution center CEAGESP. Six fish species were selected among the most available and consumed in São Paulo city: anchovy, tuna, dogfish, croaker, hake and sardine. After the sample preparation procedures, the determination of 226Ra, 228Ra, 40K and 137Cs was carried out by gamma spectrometry and the determination of 210Po by alpha spectrometry. The results obtained for all the species studied are below the limits adopted by the Brazilian Standards for 137Cs and, therefore, their consumption offers no risk due to the ingestion of this radionuclide. The concentration obtained for the radionuclides 226Ra, 210Po, 228Ra and 137Cs in the fish samples analyzed are low and of the same order of magnitude as data from the literature. The results obtained for the doses, for all the species studied, showed that their consumption offers no risk of exposure due to the ingestion of the analyzed radionuclides.Artigo IPEN-doc 28205 Determination of natural radionuclides (Ra-226, Pb-210, Po-210, Ra-228 and K-40) and Cs-137 in fish consumed in the City of São Paulo2021 - NERY, A.D.; NISTI, M.B.; SAUEIA, C.H.R.; MAZZILLI, B.P.Artigo IPEN-doc 26173 Determination of gross alpha and beta radioactivity by liquid scintillation counting in drinking water consumed in the cities of Paraná-Brazil2019 - CAMARGO, GUSTAVO E.; FERREIRA, ADEMAR O.; NERY, ANDRESSA D.; SAUEIA, CATIA R.; NISTI, MARCELO B.The liquid scintillation counting (LSC) is a technique in which the sample is mixed to a chemical organic liquid, forming a scintillation solution, capable to convert the kinetic energy of nuclear emissions into light energy photons. The aim of this study was to quantify the concentration of gross alpha and beta radioactivity in drinking water using the LSC. The water samples were collected in the Paraná cities: Telêmaco Borba, Castro, Tibagi, Reserva, Curiúva, Ponta Grossa, Imbaú and Curitiba. They have free access sources of drinking water to the public. The initial step of the methodology was standardizing the pre-concentration of the water samples by heating on a hot plate from 1 L to a final volume of 50 mL, at maximum temperature of 80°C. An aliquot of 5 mL of the final solution was mixed with 15 mL of the scintillation solution (Hisafe 3) in a vial and measured on a LSC. The equipment used for the measurement of gross alpha and beta activities was a 1220 Quantulus™ Ultra Low Level Liquid Scintillation Spectrometer. The activity concentration of gross alpha varied from <0.10 to 0.20 Bq L-1 and gross beta varied from <0.18 to 0.23 Bq L-1. The results of gross alpha and beta concentration obtained in the samples are below the maximum limits adopted by Ministry of Health in Brazil.