ANDRESSA DAMACENO NERY

ANDRESSA DAMACENO NERY

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Assessment of natural radioactivity in bottled mineral water from Brazil
2022 - 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.
Determination of natural radionuclides (Ra-226, Po-210, Ra-228 and K-40) and Cs-137 in fish consumed in the city of São Paulo
2022 - 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.
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 Paulo
2021 - NERY, A.D.; NISTI, M.B.; SAUEIA, C.H.R.; MAZZILLI, B.P.
Assessment of natural radioactivity in bottled mineral water from Brazil
2021 - NISTI, M.B.; NERY, A.D.; SAUEIA, C.H.R.; CAVALCANTE, F.
Determination of gross alpha and beta radioactivity by liquid scintillation counting in drinking water consumed in the cities of Paraná-Brazil
2019 - 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.