MARCIA PIRES DE CAMPOS

MARCIA PIRES DE CAMPOS

Full item page

Search Results

Now showing 1 - 10 of 37

Study of radon exposure, chemical and radiological characterization of spring mineral waters from Águas de Lindóia and Poços de Caldas, Brazil
2024 - REIS, G.L.; CAMPOS, M.P.; MAZZILLI, B.P.; TORRECILHA, J.K.; OLIVEIRA, N.S.; SILVA, D.A.; MARRICHI, J.M.O.; SILVA, P.S.C.
Hydrothermal resources are used for health prevention and treatment worldwide based on drinking, bathing, and immersing in thermal mineral waters. In some places, 222Rn inhalation is also present. In Brazil, several locations apply thermal and hydrotherapies integrated into the Unified Health System as in Águas de Lindóia and Thermas Antonio Carlos in Poços de Caldas Town. The effective dose due to 222Rn inhalation by the public and balneary workers, as well as the chemical and radiological characterization for these spas were evaluated. 222Rn activity concentration was measured by using CR-39, elemental water composition by neutron activation, and radionuclides, by gamma espectrometry. Results showed that the 222Rn activity concentration varied from 21 to 71 Bq m−3 in the public areas of the balnearies and from 407 to 16,451 Bq m−3 in the closed springs. Effective doses varied from 0.01 to 0.02 mSv y−1 for the public, from 0.10 to 0.33 mSv y−1 for works and from 0.03 to 4.95 mSv y−1 for maintenance. No risk occurs for members of the public and workers due to radon inhalation, but care must be taken on behalf of the maintenance workers from Águas de Lindóia balneary. The water, for both balnearies, do not exceed the recommendation for drinking water for gross alpha and gross beta activities. Chemically, the water from Águas de Lindóia is classified as hypo saline and the water from Poços de Caldas, as low mineral content.
Radon dosimetry and water chemical and radiological characterization of Brazilian spas
2024 - REIS, G.L.; SILVA, P.S.C.; CAMPOS, M.P.; TORRECILHA, J.K.; OLIVEIRA, N.S.; SILVA, D.A.; MARRICHI, J.M.O.; MAZZILLI, B.P.
Radon concentrations in a nuclear reactor center in Brazil
2021 - SILVA, PAULO S.C. da; CAMPOS, MARCIA P. de; EL HAJJ, THAMMIRIS M.; REIS, GUILHERME de L.
Radiation workers are normally exposed to doses resulting from their day-to-day activities. Besides that, background radiation, such as radon, can contribute to the exposure rates. The radionuclide 222Rn is a noble gas belonging to the uranium series, and its indoor concentration in the air depends on the exhalation from surrounding soil and the exhalation from building materials. Radon exhaling from porous building materials containing high uranium concentrations can become a significant exposure factor in areas with limited ventilation. The objective of this study was to evaluate the 222Rn concentrations in the radiochemistry and radiometric laboratories in the nuclear reactor building of the Nuclear Reactor Center (CERPq) located in the Institute of Nuclear and Energy Research (IPEN), São Paulo, Brazil. Measurements were done using a Radon Gas Monitor, model RAD7, equipped with a solid-state alpha detector. A passive method (SSNTD) was also used, consisting of square pieces of C-39 foils (2.5 cm × 2.5 cm) placed within small diffusion chambers. The CR-39 detectors were etched in KOH 30% solution at 80 °C for 5.5 h in a constant-temperature bath. After etching, the detectors were washed, dried, and scanned using a microscope to obtain the track density measurements. The activity concentrations measured with both techniques varied from 52 to 103 Bq m−3 in the studied areas of the CERPq. These values may be compared to the reference level of 100 Bq m−3 established by the World Health Organization to ensure safety environments.
Radiological evaluation of bricks made with NORM residue
2019 - CAMPOS, MARCIA P. de; NISTI, MARCELO B.; PASCHOALIN FILHO, JOAO A.; MAZZILLI, BARBARA P.
Radiological implications of using phosphogypsum as building material
2020 - MAZZILLI, B.P.; CAMPOS, M.P.; NISTI, M.B.; SAUEIA, C.H.R.; MADUAR, M.F.
Phosphogypsum, a waste byproduct derived from the production of phosphoric acid, is being worldwide stock-piled, posing concerns about the environmental problems originating from this practice. Considerations about the viability of the safe reuse of this material have been raised, among them its potential use as building material. However, as phosphogypsum can contain natural radionuclides in significant concentrations, using it as a build-ing material has radiological implications, which presently prevent such application. In order to evaluate the feasibility of using phosphogypsum in the manufacturing of building elements such as bricks and plates, a com-prehensive research was undertaken in Brazil, following a multiple approach. This research included studies related to: Brazilian phosphogypsum characterization; experimental determination of radon exhalation rate; and application of theoretical models to forecast both radon exhalation and external doses in dwellers. In this paper, a comprehensive review of the research carried out in Brazil is presented.
Calibração de detectores sólidos de traços nucleares do tipo CR-39 para medidas de Rn-222 no ar
2015 - CAZULA, C.D.; CAMPOS, M.P.; MAZZILLI, B.P.
No método de detecção com detectores sólidos de traços nucleares, quando uma partícula pesada incide sobre a superfície do detector, provoca um desarranjo em sua estrutura molecular formando um traço. Uma das aplicações mais comuns desses detectores está na medição da concentração de Rn-222 no ar, um gás nobre radioativo, membro da série do U-238, emissor de partículas alfa e importante em estudos epidemiológicos para proteção dos indivíduos à radiação natural. Para determinar a concentração de Rn-222 no ar em um ambiente é necessário conhecer a densidade de traços (traços/cm2) na superfície do detector, o tempo de exposição e o fator de calibração. A determinação do fator calibração para os detectores CR-39 foi feita a partir da exposição destes a uma concentração conhecida de Rn-222. Para tanto, os detectores foram inseridos no interior de uma célula de Lucas adaptada e posteriormente expostos a uma concentração de Rn-222 de 15 kBq/m3, por meio do aparelho RN-150 da Pylon Eletronics Incorporation, que possui uma fonte de Ra-226 e libera concentrações conhecidas de Rn-222. Foram realizadas seis determinações do fator de calibração, o valor médio obtido foi de 0,0534 ± 0,0021 (traços/cm2 por Bq/m3 dia). Os resultados são compatíveis com os valores da literatura para o mesmo tipo de detector e apresentaram boa reprodutibilidade.
Radon concentrations on the nuclear and radioactive instalations of nuclear reactor center – CRPQ/IPEN
2019 - SILVA, PAULO S.C. da; CAMPOS, MARCIA P. de; REIS, GUILHERME de L.
Nuclear and radioactive workers are normally exposed to dose resulting from their day by day activities. Besides that, the ubiquitous radon distribution can also contribute for the exposure rates. The radionuclide 222Rn is a noble gas belonging to the uranium series and its indoor concentration in the air depend on exhalation from surrounding soil and on exhalation from building materials. Radon emanating from porous building materials may achieve large relevance in areas with high uranium concentrations and areas with limited ventilation. The objective of this study was to evaluate the 222Rn concentrations in the radiochemistry and radiometric laboratories and in the reactor nuclear building of the Nuclear Reactor Center (CERPq) located in the Nuclear and Energy Research Institute (IPEN). Measurements were done by using a Radon Gas Monitor, model RAD7, produced by Durridge Company equipped with a solid state alpha detector and a passive method, with SSNTDs placed within small diffusion chambers, as detectors square pieces (2.5 cm × 2.5 cm) of CR 39 foils were used. The CR 39 detectors were etched in KOH 30% solution at 80 °C for 5.5 h in a constant temperature bath. After etching, the detectors were washed, dried, and scanned under a Carl Zeiss microscope to obtain the track density measurements. The activity concentrations varied from 52 to 103 Bq m 3 for the measured areas in CERPq. These values are in accordance with what is stablished by the World Health Organization for safe environments of 100 Bq m 3.
Determinação da taxa de exalação do 222Rn no solo do IPEN
2019 - NISTI, M.B.; CAMPOS, M.P.; SILVA, G.M.; MAZZILLI, B.P.
Radiological implications of using phosphogypsum as building material
2018 - MAZZILLI, B.P.; CAMPOS, M.P.; NISTI, M.B.; MADUAR, M.F.
Phosphogypsum recycling in the building materials industry: assessment of the radon exhalation rate
2017 - CAMPOS, M.P.; COSTA, L.J.P.; NISTI, M.B.; MAZZILLI, B.P.
Phosphogypsum can be classified as a Naturally Occurring Radioactive Material (NORM) residue of the phosphate fertilizer industry. One of the main environmental concerns of its use as building material is the radon exhalation. The aim of this study is to measure the radon exhalation rate from plates and bricks manufactured with phosphogypsum from three installations of the main Brazilian producer, Vale Fertilizantes, in order to evaluate the additional health risk to dwellers. A simple and reliable accumulator method involving a PVC pipe sealed with a PVC pipe cover commercially available with CR-39 radon detector into a diffusion chamber was used for measuring radon exhalation rate from phosphogypsum made plates and bricks. The radon exhalation rate from plates varied from 0.19 ± 0.06 Bq m 2 h 1, for phosphogypsum from Bunge Fertilizers, from 1.3 ± 0.3 Bq m 2 h 1, for phosphogypsum from Ultrafertil. As for the bricks, the results ranged from 0.11 ± 0.01 Bq m 2 h 1, for phosphogypsum from Bunge Fertilizers, to 1.2 ± 0.3 Bq m 2 h 1, for phosphogypsum from Ultrafertil. The results obtained in this study for the radon exhalation rate from phosphogypsum plates and bricks are of the same order of magnitude than those from ordinary building materials. So, it can be concluded that the recycling of phosphogypsum as building material is a safe practice, since no additional health risk is expected from the radiological point of view.