LUCIO LEONARDO

LUCIO LEONARDO

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Challenges in measuring 22Na in rainfall by gamma spectrometry in the city of São Paulo, Brazil
2023 - DAMATTO, S.R.; DOMINGOS, R.M.; TEIXEIRA, L.; ISIKI, V.L.; ALENCAR, M.M.; LEONARDO, L.
Na-22 is a naturally occurring radionuclide of cosmogenic origin with half live of 2.6 years, being a beta and gamma emitter (541keV and 1274.5keV, respectively). This cosmogenic radionuclide is mainly formed when cosmic rays interact with argon nucleus, occurring a fragmentation of this nucleus. The process of production of 22Na occur continually in upper atmosphere, lower stratosphere and rainfall is the predominantly process of deposition of cosmogenic radionuclides in terrestrial surface. Na-22 together with 7Be (T1/2) = 53.3 d, gamma ray 476.7keV) can be used as tracers in studies of aerosol transport between layers of the atmosphere. At the same time 22Na is rarely used in these studies due to its extremely low abundance in rainfall. The objectives of this work were to present the first results 22Na activity concentration measured in rainfall collected at the IPEN campus located in São Paulo, Brazil. Large volumes of rainfall samples were collected from October 2022 to April 2023, totaling 20 samples, and 22Na activity concentration was measured by non-destructive gamma-ray spectrometry using a coaxial Be-layer HPGe detector with 46% relative efficiency and associated electronic devices and live counting time varying from 250,000 s to 500,000 s; the rainfall volumes ranged from 14 L to 164 L. The collection container was previously acidified with 1mol L-1 HNO3 to avoid loss of radionuclide by absorption on the container walls. The first eight rainfall samples were collected in a catchment area of 1m2, which was not enough to measure the radionuclide, since all the determined results were smaller than the detection limit of the methodology. After these results, it was decided to increase the catchment area by collecting rainfall samples from the roof of the laboratory building, in an area of 78 m2; the container used to collect samples from this area was also acidified with 1 mol L-1 HNO3. In this new area, 12 rainfall samples were collected, however, as the volume of rainfall was very large in the rains collected, only one sample was acidified, a rainfall of 2 mm and a volume of 98 L; in the other samples, the large volume of rain did not allow the water to become acidic because the collection container overflowed with water. In the acidified rainfall sample, the result of 0.725 ± 0.252 Bq L-1 was determined for the radionuclide 22Na. With this result, it is possible to prove the importance of both the catchment area and the acidulation of the sample in the determination of trace radionuclides in rainfall samples.
Study of 7Be activity concentration in rainfall as a function of sampling height
2022 - ALMEIDA NETO, J.O.; DAMATTO, S.R.; MADUAR, M.F.; LEONARDO, L.; TEIXEIRA, L.F.; DOMINGOS, R.M.
Natural radioactivity in oilseeds commercialized in the city of São Paulo, Brazil
2022 - LEONARDO, L.; DAMATTO, S.R.; MADUAR, M.F.
Caracterização química elementar de matrizes biológicas empregando a técnica de INA
2022 - LEONARDO, LUCIO; DAMATTO, SANDRA R.
A INAA foi utilizada no estudo do uso de líquens Canoparmelia texana como bioindicador ambiental de radionuclídeos e metais em região impactada por NORM, na proposta de uso da tartaruga de água doce Trachemis scripta elegans como bioindicadora ambiental em áreas urbanas de São Paulo e com o objetivo de caracterização química elementar dos produtos derivados da Nicotiana tabacum L. Foram determinados nas irradiações realizadas no reator IEA-R1 do IPEN, os elementos As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb e Zn usando os materiais de referência lichen, folhas de pêssego, folhas de tomate, peixe e mexilhão. Os resultados indicaram a possibilidade do uso da espécie de liquens como bioindicador de radioatividade e metais, pois as concentrações máximas obtidas de 53 ± 5 mg kg-1, 79 ± 8 mg kg-1, 135 mg kg-1 para os elementos Hf, Ta e ΣETR, foram maiores que as concentrações 1,51 ± 0,05 mg kg-1, 1,70 ± 0,22 mg kg-1 e 8,5 mg kg-1 da amostra considerada background, respectivamente, indicando o enriquecimento dos elementos citados. Nas amostras da tartaruga de água doce, os referidos elementos químicos foram determinados no casco, tecido epidérmico córneo, músculo, rim, coração e pulmões e as maiores concentrações foram para os elementos Ca, K e Na. Nas amostras de escudo epidérmico e casco foi observada a presença de Zn que pode ser uma característica da espécie ou uma contribuição do ambiente, sendo necessário mais amostras para a verificação da possibilidade de uso da espécie como bioindicador. Nos produtos derivados da Nicotiana tabacum L. comercializados em algumas regiões do Brasil, como cigarros, charutos, fumo de corda e rapé, os elementos que apresentaram maiores concentrações foram Ba, Br, Ca, Ce, K, e Zn.
Natural radionuclides in soil profiles and sediment cores from Jundiaí reservoir, state of São Paulo
2021 - GONÇALVES, P.N.; DAMATTO, S.R.; LEONARDO, L.; SOUZA, J.M.
The activity concentration of natural radionuclides in soils and sediments is dependent on many factors, such as the rock parental material, pedogenic and weathering processes, physical and chemical properties of the environment, anthropogenic sources, among other aspects. There are few studies about the levels of natural radionuclides in reservoirs in both, international and national, literature. The objective of this paper was to evaluate the activity concentrations of 238U and 232Th by Instrumental Neutron Activation Analysis and 226Ra, 210Pb, 228Ra, 228Th and 40K by gamma spectrometry in two soil profiles and three sediment cores collected in the catchment area of Jundiai reservoir, located in the state of São Paulo, Brazil. Principal component analysis was applied to verify the correlation of the activity concentrations of the natural radionuclides with physical and chemical properties of soil and sediment samples. The mean activity concentrations of the radionuclides in the soil profiles 1 and 2 were, respectively: 238U – 37(1) and 32(1) Bq.kg-1; 232Th – 91(1) and 60(1) Bq.kg-1; 226Ra – 66(1) and 51(1) Bq.kg-1; 210Pb – 35(1) and 37(1) Bq.kg-1; 228Ra – 34(1) and 27(1) Bq.kg-1; 228Th – 78(1) and 58(1) Bq.kg-1; 40K – 96(2) and 171(7) Bq.kg-1. For the three sediment cores analyzed, the average activities concentrations of the radionuclides were, respectively: 238U – 64(0.5), 47(0.1) and 44(0.2) Bq.kg-1; 232Th – 122(2), 100(1) and 64(1) Bq.kg-1; 226Ra – 74(2), 71(1) and 45(1) Bq.kg-1; 210Pb – 70(3), 56(2) and 55(2) Bq.kg-1; 228Ra – 53(1), 41(1) and 33(1) Bq.kg-1; 228Th – 100(2), 92(1) and 63(2); 40K – 316(5), 237(1) and 136(2) Bq.kg-1.
Aspectos nutricionais e radioatividade natural nas castanhas brasileiras
2019 - OLIVEIRA, GABRIEL F.M.; SILVA, SANDRA M.C.; BORGES, LARISSA; DAMATTO, SANDRA R.; LEONARDO, LUCIO; MADUAR, MARCELO F.
INTRODUÇÃO As oleaginosas são sementes originadas de frutos e possuem uma vasta quantidade de nutrientes essenciais para a nutrição humana, são caracterizadas pela presença de vitaminas, minerais, fibras, gorduras boas e alguns compostos bioativos. A ingestão desse grupo de alimentos pode proporcionar benefícios como: diminuição dos níveis de colesterol e triglicerídeos sanguíneos; regulação da atividade imunológica e resposta inflamatória; aumento da atividade apoptótica de células neoplásicas e prevenção de acidente vascular encefálico. A radioatividade natural está presente em todos os compartimentos do ecossistema terrestre e no ser humano, originada dos radionuclídeos naturais encontrados na crosta terrestre. A radioatividade natural chega até o homem pela cadeia alimentar, por meio dos alimentos vegetais e animais fazendo com que todos os alimentos possuam diferentes concentrações dos radionuclídeos naturais. Embora existam trabalhos sobre a caracterização de radionuclídeos naturais, um número limitado de trabalhos pode ser encontrado na literatura quanto à quantificação destes radionuclídeos nas oleaginosas, fazendo necessário mais pesquisas. OBJETIVOS O objetivo do presente estudo foi avaliar a composição centesimal da farinha de coco, castanha do Brasil, castanha de baru, castanha de caju e os níveis de radioatividade natural da farinha de coco, castanha do Brasil, pecam brasileira, castanha de baru, castanha de caju e pinhão cru e cozido. METODOLOGIA A análise bromatológica seguiu as normas elaboradas pela AOAC (2010) e pelo Instituto Adolfo Lutz (2008) e a determinação dos radionuclídeos naturais foi realizada por espectrometria gama utilizando um detector de germânio hiperpuro. RESULTADOS Os resultados referentes à análise comparativa das oleaginosas demonstram que a castanha de caju é a oleaginosa com maior teor proteico e que a castanha do Brasil apresentou altos índices de gordura. Por outro lado, a farinha de coco é uma boa fonte de fibras. As maiores concentrações de atividade de 226Ra foram obtidas na castanha do Brasil e de 40K na amostra de farinha de coco. Somente na amostra de castanha do Brasil foram determinadas as concentrações de atividade de 228Th e 228Ra. A amostra de pinhão cozido apresentou menores valores de concentração de atividade para os radionuclídeos determinados. CONCLUSÃO Embora apresente radioatividade, os benefícios da ingestão destes alimentos são maiores, desde que não ultrapasse uma porção por dia.
Activity concentrations of natural and artificial radionuclides in feline dry food
2015 - CAVALCANTE, F.; PECEQUILO, B.R.S.; LEONARDO, L.
Natural radiation exposure is an inherent condition to all living species, once radionuclides from the 238U and 232Th chain can nearly be found in all places. Information on radionuclides concentration and exposure levels, from natural and anthropogenic sources are absolutely necessary to investigate the possible effects that ionizing radiation can induce. These can be very different depending on the organism considered and the exposure pathway. In recent decades, the exposure of non-human species to ionizing radiation has been specially considered and investigated (ICRP, 2014) by a vast number of scientists and organizations, once they differ widely from the exposure of human beings. Brazil holds the second largest cat and dog population in the world, consuming over 2 million tons of feed every year. The country also stands out for its production of pet food that produced 2.4 million of tons of feed in 2014, representing the world’s second largest industry. A novel study regarding the radionuclide content in different dog and cat food is being developed since 2013 and preliminary results have been presented by Cavalcante, F. and Pecequilo (2014), for selected dry dog food. The present study presents an evaluation of the radionuclide and radioactivity content of different brands of dry cat food, commonly found in local markets in the city of Sao Paulo, Brazil. Thirteen different samples were crushed into powder and kiln dried before tightly sealed in 100 mL HDPE flasks, with a plan screw cap and bubble spigot. These samples, after resting for 30 days to ensure secular equilibrium, were placed in an extended range coaxial germanium detector (Canberra XtRa GX4020 detector) for 150 ks and the acquired spectra were analyzed with the InterWinner 6.0 software (InterWinner, 2004). The natural radionuclides considered were 238U, 232Th and 40K, the anthropogenic radionuclides investigated were 60Co, 131I, 137Cs and 134Cs. The results for the considered artificial radionuclides have shown activity concentration values below the detector’s MDA (Minimum Detectable Activity), as in Table 1. The concentrations of natural radionuclides ranged from 1.12 ± 0.29 Bq/kg to 3.77 ± 0.36 Bq/kg for 226Ra; from 1.48 ± 0.40 Bq/kg to 6.27 ± 0.78 Bq/kg for 232Th and from 216.8 ± 11.2 Bq/kg to 361.7 ± 16.8 Bq/kg for 40K, as shown in Figure 1. The results suggest that the samples evaluated have no contamination of artificial radionuclides and the natural radionuclides concentration will not contribute to significant absorbed dose by their ingestion. Therefore, the authors conclude that these studied brands carry no radiological risk for the animals ingesting them.
Natural radionuclides in soil profiles and sediment cores from Jundiai reservoir, state of São Paulo
2019 - GONÇALVES, PEDRO do N.; DAMATTO, SANDRA R.; LEONARDO, LUCIO; SOUZA, JOSEILTON M. de
The activity concentration of natural radionuclides in soils and sediments is dependent on many factors, such as the rock parental material, pedogenic and weathering processes, physical and chemical properties of the environment, anthropogenic sources, among other aspects. Naturally occurring radiation in the environment is mostly due to the decay of 238U and 232Th series; another important source of natural radiation is the radionuclide 40K. Reservoirs are artificial systems made in order to stock riverine and rainwater to supply water to the population. There are few studies about the levels of natural radionuclides in reservoirs in both, international and national, literature. The objective of this paper was to evaluate the activity concentration of 238U and 232Th by Instrumental Neutron Activation Analysis and 226Ra, 210Pb, 228Ra, 228Th and 40K by gamma spectrometry in two soil profiles and three sediment cores collected in the catchment area of Jundiai reservoir, located in the state of São Paulo, Brazil. Principal component analysis was applied to verify the correlation of the activity concentrations of the natural radionuclides with physical and chemical properties of soil and sediment samples. In the soil profiles, the radionuclides that showed higher activity concentration when compared to the UNSCEAR values were 232Th in the both profiles and 238U only in one; for the sediment cores, the activity concentrations of 238U and 232Th were higher than the UNSCEAR values in all the samples analyzed and also for the radionuclide 226Ra in two sediment cores.
Radionuclides of natural origin in environmental samples collected in the catchment area of Ponte Nova reservoir, São Paulo, Brazil
2018 - SILVA, A.R.; DAMATTO, S.R.; LEONARDO, L.; GONÇALVES, P.N.; SOUZA, J.M.; MADUAR, M.F.
Natural radiation is generally classified as terrestrial primordial radiation or cosmogenic radiation. Primordial radiation is mostly due to the decay series of 238U and 232Th and is present in soil, sediments and water; another important source of natural radiation is 40K. Reservoirs are a very dynamic system with several phenomena to study, due to their huge impact on ecosystems and river flow. Ponte Nova reservoir (23°34'43.23"S, 45°56'56.76"W) is the first reservoir in a cascade system that was built in the 1970s to control the Upper Tietê River basin water flow. In the present work, the activity concentrations of 238U, 226Ra, 210Pb, 232Th, 228Th, 228Ra and 40K were determined using instrumental neutron activation analysis and gamma spectrometry in soil profiles collected in the catchment area of Ponte Nova Reservoir and sediment cores collected close to the soil samples. The highest concentration obtained in the soil samples was for 40K that varied from 49 to 2410 Bq/kg and 210Pb in the sediment samples, which varied from 20 to 774 Bq/kg. Cluster analysis and principal component analysis were applied to all the results obtained to verify a probable correlation between the radionuclides determined in the soil and sediment samples.
Inorganic chemical characterization of the soil and sediment from Taiaçupeba Reservoir, São Paulo
2017 - LEONARDO, L.; SOUZA, J.M.; DAMATTO, S.R.; SURKOV, A.M.; MADUAR, M.F.; SILVA, A.R.
Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê –SPAT) and it is responsible for water supply for about 3.1 million of people. The water quality of a reservoir became very important in the last decades due to the increase of environmental degradation of the soil and its several uses. Trace and major elements can accumulate in high levels in soil and sediment, and the study of its concentration can indicate if the ecosystem is polluted. Therefore, the study of soil profiles and sediment cores are an important tool for the understanding of geophysical and geochemical aspects of aquatic ecosystems. The objective of this work was to present the elements As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Ta, Tb, Th, U, Yb and Zn concentrations using Instrumental Neutron Activation Analysis (INAA) in four soil profiles and four sediment cores collected in the influence area of Taiaçupeba reservoir. To verify if these elements could be enriched and the ecosystem polluted the Enrichment Factor and the Geoacumulation Index were also used. Soil profiles were collected in trenches up to 2m deep and sampled every 5 cm; in the laboratory the samples were dried at room temperature. The sediment samples were collected with a manual PVC sampler sliced every 2 cm or according to their textural characteristics, and dried in an oven at 50 C; the length of the sediment cores ranged from 42 cm to 61 cm. After drying, soil and sediment samples were sieved in a 2 mm mesh and packed in polyethylene bottles for INAA. The elements Na, As and Sb presented the highest values for both soil and sediment samples, implying in continuous, regular and spatial monitoring of the reservoir. One sediment core presented a very high concentration of the element Zn when compared to the values of the Upper Continental Crust, indicating a possible anthropic contribution from the region’s industries and classifying the reservoir as extremely polluted in relation to this element. In the evaluation of the enrichment factor it was concluded that the soil presented very high enrichment for the elements Na, As and Sb and the sediment presented very severe enrichment for the elements Na, As and Zn.

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