BRIGITTE ROXANA SOREANU PECEQUILO

BRIGITTE ROXANA SOREANU PECEQUILO

(Fonte: Lattes)

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Bachelor in Physics, University of São Paulo (1967), Master in Nuclear Technology, University of São Paulo (1971) and PhD in Nuclear Technology, University of São Paulo (1977). Was researcher at the Institute of Energy and Nuclear Research (IPEN) from 1969 to 2014. Currently is a collaborator of IPEN with the project "Gamma Spectrometry and trace detectors as tools for evaluation of natural and artificial radioactivity in several samples" and superviser at the Graduate Program of IPEN. Has experience in nuclear engineering, with emphasis on Radioisotopes Applications, acting on the following topics: nuclear instrumentation, dose assessment, environmental monitoring, natural radioactivity, alpha and gamma spectrometry, gross alpha and beta radioactivity measurements and nuclear trace detectors . As IAEA expert in the determination of radioactivity concentrations with alpha and gross beta counting systems with low background proportional detector had been in Asuncion, Paraguay (2004) and in Cuenca, Ecuador (2007). Since 1978 is professor in charge of the graduate course of IPEN, Advanced Topics in Nuclear Measurements. (Text obtained from the Currículo Lattes on October 6th 2021)

Possui graduação em Bacharel Em Física pela Universidade de São Paulo (1967), mestrado em Tecnologia Nuclear pela Universidade de São Paulo (1971) e doutorado em Tecnologia Nuclear pela Universidade de São Paulo (1977). Foi pesquisadora do Instituto de Pesquisas Energéticas e Nucleares (IPEN) de 1969 a 2014. Atualmente é colaboradora do IPEN com o projeto "Espectrometria gama e detectores de traços como ferramentas para avaliação de radioatividade natural e artificial em amostras diversas" e orientadora no Programa de Pós-Graduação do IPEN. Tem experiência na área de Engenharia Nuclear, com ênfase em Aplicações de Radioisótopos, atuando principalmente nos seguintes temas: instrumentação nuclear, avaliação de dose, monitoracao ambiental, radioatividade natural, espectrometria alfa e gama, medidas de radioatividade alfa e beta total e detectores de traços. Como expert da AIEA na operacionalização de sistemas de contagem alfa e beta total com detector proporcional de baixa radiação de fundo para a determinação da concentração de radioatividade em água potável, esteve em Assunção, Paraguai (2004) e em Cuenca, Equador (2007). Desde 1978 é professora-responsável do curso de pós-graduação do IPEN, Tópicos Avançados de Medidas Nucleares. (Texto extraído do Currículo Lattes em 06 out. 2021)

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Multi-elemental analysis by FRXDE on pollen produced by the native bee Scaptotrigona aff. Fake
2023 - GIOVANNI, DALTON N. da S.; ZAMBONI, CIBELE B.; PECEQUILO, BRIGITTE R.S.; ALIFIO-ESPOSITO, SELENE; PIMENTA, DANIEL C.; SIMONS, SIMONE M.
Brazil is one of the largest suppliers of bee products in the world. It is currently the 5th largest exporter of honey and derivatives and a significant part of its production originates from the south and northeast. Specifically, the species Scaptotrigona aff. Postica, from the region of Barra do Corda in the State of Maranhão (MA), produces pollen which is one of the main activities of the local economy (food supplement). However, there are no data on its mineral composition, although there is a history of applications in the nutritional field. In this context, this research aims to generate integrated and interdisciplinary knowledge of the pollen produced by this pollinating species, through multi-element investigation (identification and quantification of chemical elements) using the Energy Dispersive X-ray Fluorescence (XRF) technique. The elemental composition of pollen emphasizes its nutritional relevance (Ca, Cl, Fe, K, Mn and P) and the results of the concentrations showed little seasonal variation, serving as a model for the safe expansion of meliponiculture in the region. In the technological sphere, this analysis is a tool for tracking (provenance), which allows the identification of fraud and/or adulteration, in addition to adding quality control to its commercialization.
Multielemental characterization of the pollen produced by Scaptotrigona aff postica bee from Brazil using EDXRF technique
2023 - SILVA, DALTON G.N. da; ZAMBONI, CIBELE B.; PECEQUILO, BRIGITTE R.S.; ESPOSITO, SELENE E.; PIMENTA, DANIEL C.; SIMONS, SIMONE M.
The objective of this investigation was to perform a multielemental characterization of the pollen produced by Scaptotrigona aff Postiça Bee (popularly known as “tubi”). In recent years, the demand for natural and healthy products has grown significantly and products from Meliponiculture (creation of stingless bees) have started to be consumed on a larger scale in Brazil. Specifically, pollen has gained prominence in the nutritional field for being a protein source and rich in carbohydrates, lipids, mineral trace elements, fibers, hormones and vitamins, but scientific research is still scarce, especially regarding studies of its specific composition. The aim of this investigation was to evaluate the content of inorganic elements (multielemental analysis) in pollen from “tubi” bees. Pollen samples were collected during a one year, in a meliponary of Barra do Corda city, in the state of Maranhão. The EDXRF analyzes were carried out using an X-Ray Fluorescence spectrometer (X-123SDD, Amptek), constituted by a Silicon detector coupled a mini X-ray tube (Ag). These data are the first estimates of mineral trace elements in this natural product and provide benefits to beekeepers regarding their characteristic specifications. In addition contributes with relevant data in the nutritional field.
Traceability of the propolis produced by Scaptotrigona Aff Postica bee from Brazil using NAA technique
2022 - ZAMBONI, C.B.; GIOVANNI, D.N.S.; PECEQUILO, B.R.S.; ESPOSITO, S.E.; PIMENTA, D.C.; SIMONS, S.M.
In the Northeast, meliponiculture presents itself as one of the zootechnical activities that has grown the most in recent years, due to its low implementation and maintenance cost, as well as a quick financial return. Meliponiculture is the creation of stingless bees (Meliponines) for the production and commercialization of beehives, honey, propolis, pollen and resins, in addition to these bees being the main agents of pollination and conservation of local biodiversity. The propolis produced by the Scaptotrigona Aff Postica bee (popularly known as the tubi bee) have several medical applications (bactericidal, fungicidal and virucidal), in addition to its use in the nutritional field. This species is found in the mainly in the Barra do Corda County (Maranhão) and it is the major source of income in the northeast region. Nowadays, food authentication has been a concern of producers and consumers around the world. For this reason, there is a growing need for reliable analytical techniques to provide an answer about food authenticity. With the goal for determining chemical descriptors for geographic origin (standardization), nuclear techniques are useful analytical tools with a highlight for Neutron Activation Analysis (NAA). The NAA measurement was performed in the nuclear reactor (IEA-R1, 3-4 MW, at IPEN). Propolis samples were collected monthly during a one year, directly from beehives of Scaptotrigona Aff Postica in a meliponary of Barra do Corda city (5° 30' 21'' S and 45° 14' 6'' W). The results were compared with two other species from south region. The database will aid in fraud detection of the propolis from the northeast region in Brazil.
Dose rates evaluation of some granitic rocks from the Paraná state
2021 - FERREIRA, A.O.; PECEQUILO, B.R.S.
Granitic rocks, widely used as building materials, are known to contain natural radionuclides and can be an important source of radiation for the population. Thirty-four samples of granite rocks from geological occurrences in Paraná state were measured with detector for evaluation of 226Ra, 232Th and 40K activity concentrations. The effective annual external dose was evaluated from these radionuclides activities using a dosimetric room model with dimensions 4 m x 5 m x 2.8 m in which all walls are internally coated with 2 cm thickness granites and considering the annual exposure time of 7000 h, suggested by the European Commission on Radiological Protection for superficial coating materials. The internal exposure was evaluated from radon air concentration of the model room, simulated from an exhalation rate of 222Rn, determined with CR-39 solid state nuclear track detectors by the sealed can technique, considering a ventilation rate of 0.5 h-1 and the same annual exposure time of 7000 h. The results for external gamma rays showed an increase in the annual effective dose ranging from 96 ± 4 μSv.a-1 to 223 ± 7 μSv.a-1 and, for radon inhalation, an increase in the ranging from 0.4 ± 0.04 μSv.a-1 to 70 ± 4 μSv.a-1. All results stayed below the recommended value by the European Commission on Radiological Protection, of 1 mSv.a-1.
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.
Preliminary results of natural radioactivity in flours commercialized in the city São Paulo by high resolution gamma ray spectrometry
2019 - SILVA, GRAZIELA M. da; PECEQUILO, BRIGITTE R.S.
In the present work, the activity concentrations of natural radionuclides 226Ra, 232Th and 40K were analyzed in 32 samples of wheat, corn, manioc and rice flours commonly used by residents of the city of São Paulo, Brazil. All samples were dried, homogenized and tightly sealed in standard 100 mL HDPE flasks with plan screw cap and bubble spigot and measured for 150 ks by gamma spectrometry with an Extended Range Coaxial germanium detector (Canberra GX4020 detector), after approximately 4 weeks storage, in order to ensure secular equilibrium. All spectra were analyzed with the InterWinner 6.0 software. The 226Ra activity concentration was determined from the weighted average concentrations of 214Pb and 214Bi. The 232Th activity concentration was determined from the weighted average concentrations of 228Ac, 212Pb and 212Bi and the 40K one from its single gamma transition. The 226Ra, 232Th and 40K activity concentrations results ranged, respectively, from 0.97 Bq/kg ± 0.42 Bq/kg to 4.75 Bq/kg ± 0.82 Bq/kg, from 8.07 Bq/kg ± 2.36 Bq/kg to 19.02 Bq/kg ± 3.56 Bq/kg and from 25.22 Bq/kg ± 4.38 Bq/kg to 153.5 Bq/kg ± 17.02 Bq/kg.
Dose rates evaluation of some granitic rocks from the Paraná state
2019 - FEREIRA, ADEMAR DE OLIVEIRA; PECEQUILO, BRIGITTE R.S.
Granitic rocks, widely used as building materials, are known to contain natural radionuclides and can be an important source of radiation for the population. Thirty-four samples of granite rocks from geological occurrences in Paraná state were measured with an HPGe detector for evaluation of226Ra, 232Th and 40K activity concentrations. The effective annual external dose was evaluated from these radionuclides activities using a dosimetric room model with dimensions 4 m x 5 m x 2.8 m in which all walls are internally coated with granites of thickness 2 cm and considering an annual exposure time of 7000 h. This value was suggested by the European Commission on Radiological Protection for superficial coating materials. The internal exposure was evaluated from radon air concentration of the model room, simulated from an exhalation rate of 222Rn, determined with CR-39 solid state nuclear track detectors using the sealed can technique, considering a ventilation rate of 0.5 h-1 and an annual exposure time of 7000 h. The results of this study showed that the increase in the annual effective dose ranged from 62 ± 3 μSv.a-1 to 138 ± 1 μSv.a-1 from external gamma rays and the increase in the annual effective dose ranged from 0.39 ± 0.04 μSv.a-1 to 70 ± 4 μSv.a-1 from radon inhalation. All results stayed below 1 mSv.a-1 recommended by the European Commission on Radiological Protection.
Preliminary results of natural radioactivity evaluation in underground waters of the city of Campos do Jordao, SP, Brazil
2019 - AFFA, GABRIEL B.; PECEQUILO, BRIGITTE R.S.
Twenty-eight 5-liter samples were collected during the year of 2018 on four different campaings (January, April, August and December) for seven selected sources (SP-123, Britania, Amizade, Dom Bosco, Volta Fria, Simao and Renato) of easy and free access to the population on the city of Campos do Jordão, SP, Brazil. Samples were concentrated from 1L to 50 mL of which 4 mL pipetted on 60 mm diameter stainless steel planchet were analyzed with a Berthold’s PC-controlled 10-channel Low-level Alpha-Beta Counter LB 770 Win in three 120-minute counting cycles. Preliminary results have shown low alpha and beta activity concentrations for all sources with values ranging between 0.0288 Bq/L ± 0.0036 Bq/L and 0.1059 Bq/L ± 0.0118 Bq/L for alpha activity and between 0.0371 Bq/L ± 0.005 Bq/L and 0.1352 Bq/L ± 0.0148 Bq/L for beta activities. Results showed a tendency of higher concentrations during periods of drier weather. All obtained values are below the limits of 0.5 Bq/L and 1 Bq/L, respectively for alpha and beta activity concentrations, recommended by the 2017 WHO Guideline on Drinking Water Management.
Self-attenuation factors in gamma-ray spectrometry of samples containing radionuclides of natural origin
2018 - PECEQUILO, B.R.S.; CAVALCANTE, F.; BARROS, L.F.; FERREIRA, A.O.; FONSECA, L.M.; MATEUS, C.
High resolution gamma-ray spectrometry is currently the most widely used analytical technique for qualitative and quantitative determination of radionuclides. Quantification of elements relies on the correct analysis of the spectra, depending strongly on the efficiency calibration of the measurement apparatus, most often performed with aqueous standard multi-radionuclide solutions. For efficiency calibration curves obtained by this method and for samples containing radionuclides of natural origin such as sand, soil, rocks and wall paint with apparent typical densities higher than that of water, self-attenuation correction factors were experimentally determined for hundreds of different samples using the Cutshall transmission technique. The results show that, to obtain more reliable analyses, correction factors for the self-attenuation behaviour, especially in the lower part of the energy spectrum, should be used. Since attenuation depends not only on the density of the sample but also on its chemical composition, correction factors have to be determined for each sample.
Concentrations of 226Ra, 232Th and 40K in Brazilian wall paint
2018 - FONSECA, L.M.; PECEQUILO, B.R.S.
Geological materials used as building materials are a source of radiation exposure due to the presence of radionuclides of natural origin. Wall paint is one of the building materials to be considered for radiological evaluation as it generally contains titanium dioxide pigment obtained from minerals such as ilmenite and rutile which contain 238U and 232Th series radionuclides and 40K. In this work, radionuclide concentrations were determined in 50 commercial Brazilian white latex wall paints using high resolution gamma-ray spectrometry. The following activity concentrations were measured: 1.41–38.7 Bq/kg (226Ra), 0.9–101.2 Bq/kg (232Th) and 5.9–256 Bq/kg (40K). These results demonstrate that the wall paints studied in this work are safe for use.