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1.
Sci Total Environ ; 802: 149829, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464794

RESUMO

A considerable amount of data has been published on the accumulation of radiocaesium (134Cs and particularly, 137Cs) in wild fungi since the first anthropogenically influenced releases into the environment due to nuclear weapon testing, usage and subsequently from major accidents at nuclear power plants in Chernobyl (1986) and Fukushima (2011). Wild fungi are particularly susceptible to accumulation of radiocaesium and contamination persists for decades after pollution events. Macromycetes (fruiting bodies, popularly called mushrooms) of the edible fungal species are an important part of the human and forest animal food-webs in many global locations. This review discusses published occurrences of 134Cs and 137Cs in twenty four species of Tricholoma mushrooms sourced from the Northern Hemisphere over the last five decades, but also includes some recent data from Italy and Poland. Tricholoma are an ectomycorrhizal species and the interval for contamination to permeate to lower soils layers which host their mycelial networks, results in a delayed manifestation of radioactivity. Available data from Poland, over similar periods, may suggest species selective differences in accumulation, with some fruiting bodies, e.g. T. portentosum, showing lower activity levels relative to others, e.g. T. equestre. Species like T. album, T. sulphurescens and T. terreum also show higher accumulation of radiocaesium, but reported observations are few. The uneven spatial distribution of the data combined with a limited number of observations make it difficult to decipher any temporal contamination patterns from the observations in Polish regions. When data from other European sites is included, a similar variability of 137Cs activity is apparent but the more recent Ukrainian data appears to show relatively lower activities. 40K activity in mushrooms which is associated with essential potassium, remains relatively constant. Further monitoring of 137Cs activity in wild mushrooms would help to consolidate these observations.


Assuntos
Agaricales , Micorrizas , Radioatividade , Tricholoma , Radioisótopos de Césio/análise , Humanos , Micorrizas/química , Polônia , Solo
2.
Chemosphere ; 286(Pt 3): 131942, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426265

RESUMO

Radioactivity monitoring post-cold war has become more complex due to the nuclear fallout and the surge in use of radioactive materials. This requires novel methods to detect, trace and distinguish natural and anthropogenic radioactive sources in the environment. We explored the feasibility of using ZrSiO4 (Zircon), as a reference signature for radioactivity monitoring due to the unique phenomenon of metamictization. We investigated the variations in microstructural properties of Zircon samples collected from a proposed Uranium site to identify these signatures using analytical techniques such as Gamma-ray Spectroscopy, XRD and Raman spectrum analysis. Besides elevated levels of radioactivity, the samples exhibited distinct properties such as increased lattice parameters observed from the XRD analysis and dramatic broadening of A1g (439 cm-1) and B1g (1008 cm-1) vibrational modes in the Raman spectrum. Structural parameters were further analyzed by modeling the crystal from experimentally observed lattice parameters. Ab-initio calculations were then performed on the modeled structure providing more insight into the microstructural variations. Samples collected from proposed Uranium mines indicate an increase of 1.226% and 0.9389% in Si-O and Zr-O bond lengths of the Zircon crystal signifying the ongoing process of metamictization from radiation damage. By correlating radioactivity levels with the lattice parameters variations of the collected samples, the study establishes a linear relation between the degree of damage to a mineral's crystal structure and the amount of radioactivity. We propose to use the variations in damage found in a mineral's structure as a nuclear forensic signature for advanced assessment of accumulated radioactivity in a particular geographical location.


Assuntos
Elementos Radioativos , Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Urânio , Estudos de Viabilidade , Poluentes Radioativos do Solo/análise , Urânio/análise
3.
Chemosphere ; 287(Pt 3): 132313, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34592206

RESUMO

Radioactive ions with high-heat release or long half-life could cause long-term influence on environment and they might enter the food chain to damage human body for their toxicity and radioactivity. It is of great importance to develop methods and materials to detect and remove radioactive ions. Carbon dots and their composite materials has been applied widely in many fields due to their plentiful raw materials, facile synthesis and functional process, unique optical property and abundant functional groups. This comprehensive review focuses on the preparation of CDs and composite materials for the detection and adsorption of radioactive ions. Firstly, the recent-developed synthetic methods for CDs were summarized briefly, including hydrothermal/solvothermal, microwave, electrochemistry, microplasma, chemical oxidation methods, focusing on the influence of CDs properties. Secondly, the synthetic methods for CDs composite materials were classified to four categories and summarized generally. Thirdly, the application of CDs for radioactive ions detection and adsorption were explored and concluded including uranium, iodine, europium, strontium, samarium et al. Finally, the detection and adsorption mechanism for radioactive ions were searched and the perspective and outlook of CDs for detection and adsorption radioactive ions have been proposed based on our understanding.


Assuntos
Pontos Quânticos , Radioatividade , Adsorção , Carbono , Humanos , Íons
4.
Environ Monit Assess ; 193(12): 822, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34792660

RESUMO

A comprehensive measurement of concentrations of the natural radionuclides 238U, 232Th and 40K, and 226Ra in the soil and rocks along with natural uranium and tritium activity levels in lake water were carried out during the Indian expedition to Antarctica. The samples were collected from the Larsemann Hills region in Antarctica (latitude 69°20' S to 69°25'S, longitude 76°6' E to 76°23'E). The data on the natural radioactivity for this region is limited. The study was carried out to establish baseline levels of radioactivity in different terrestrial matrices of this region such as soil, rocks, and lake water. A radiation survey mapping for terrestrial radioactivity was conducted in the region before collection of soil and rock samples. The soil and rock samples were analyzed for natural radioactivity concentrations using high-resolution gamma spectroscopy system. The major contributor to elevated gamma radiation background is attributed to the higher concentration of 232Th and 40K radionuclides in both soil and rocks. Terrestrial components of gamma dose rate due to natural radioactivity have been estimated from the measured radioactivity concentrations and dose conversion coefficients. Several "hotspots" and high background areas in the region have been identified having significantly higher concentration of 232Th and 40K. Rocks in Larsemann Hills region showed high reserve of thorium mineralization in monazites and 40K in K-feldspar. The concentrations of 232Th in soil are found to be in the range of 106-603 Bq/kg, whereas in rock it is in the range of 8-4514 Bq/kg. Natural radioactivity U (nat) and 3H contents in the lake water samples in Larsemann Hills region were estimated as 0.4 and 1.3 Bq/L and are well within the prescribed limit of radioactivity in drinking water as recommended by World Health Organization.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Regiões Antárticas , Radiação de Fundo , Lagos/análise , Radioisótopos de Potássio/análise , Solo , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
5.
Artigo em Inglês | MEDLINE | ID: mdl-34769689

RESUMO

A particular category of jewelry is one involving bracelets and necklaces that are deliberately made to contain naturally occurring radioactive material (NORM)-purveyors making unsubstantiated claims for health benefits from the release of negative ions. Conversely, within the bounds of the linear no-threshold model, long-term use presents a radiological risk to wearers. Evaluation is conducted herein of the radiological risk arising from wearing these products and gamma-ray spectrometry is used to determine the radioactivity levels and annual effective dose of 15 commercially available bracelets (samples B1 to B15) and five necklaces (samples N16 to N20). Various use scenarios are considered; a Geant4 Monte Carlo (Geant4 MC) simulation is also performed to validate the experimental results. The dose conversion coefficient for external radiation and skin equivalent doses were also evaluated. Among the necklaces, sample N16 showed the greatest levels of radioactivity, at 246 ± 35, 1682 ± 118, and 221 ± 40 Bq, for 238U, 232Th, and 40K, respectively. For the bracelets, for 238U and 232Th, sample B15 displayed the greatest level of radioactivity, at 146 ± 21 and 980 ± 71 Bq, respectively. N16 offered the greatest percentage concentrations of U and Th, with means of 0.073 ± 0.0002% and 1.51 ± 0.0015%, respectively, giving rise to an estimated annual effective dose exposure of 1.22 mSv, substantially in excess of the ICRP recommended limit of 1 mSv/year.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Método de Monte Carlo , Radioisótopos de Potássio/análise , Doses de Radiação , Radiografia , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
6.
Environ Monit Assess ; 193(11): 749, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34694473

RESUMO

There are no results of comparative ecological studies of the radionuclide activity concentration in the plants and soil in relation to geological substrate. Presented research encompasses the comparative analysis of the concentration of four radionuclides, three natural (40K, 226Ra, 232Th) and one artificial (137Cs) in soil samples and aerial plant parts of Teucrium montanum from different natural habitats on serpentinite and calcareous geological substrate. The activity concentrations of radionuclides were measured with high purity germanium (HPGe) detector and expressed as Bq kg-1. The calculated activity concentrations of 40K, 226Ra, 232Th, and 137Cs in soil samples from serpentinite/calcareous habitats are in range 39.6-91.0/59.3-1018.8, 1.7-5.5/4.3-52.4, 2.4-10.9/5.9-72.9, and 57.2-844.9/29.6-701.5 Bq kg-1, respectively. The activity concentrations of 40K, 226Ra, 232Th, and 137Cs in plant samples are in range 152.9-445.9/228.0-521.4, n.d.-1.2/0.6-5.6, n.d./0.2-0.9, and 1.0-46.4/1.7-7.0 Bq kg-1, respectively. The obtained results showed that the quantities of 137Cs are greater in the soil and plant material from the serpentinite habitats, while quantities of 40K, 226Ra, and 232Th are greater in the soil and plant material from calcareous habitats. In general, the level of radioactivity in plants and soil depends on the type of the geological substrate. The content of radionuclides in plants is correlated with the radionuclide content in the soil. In addition to other specifics in physical and chemical properties, serpentinite habitats are characterized by an increased amount of Cs in the soil, which causes an increased amount of this radionuclide in plants such as Teucrium montanum.


Assuntos
Lamiaceae , Radioatividade , Poluentes Radioativos do Solo , Teucrium , Ecossistema , Monitoramento Ambiental , Poluentes Radioativos do Solo/análise
7.
J Pharmacol Toxicol Methods ; 112: 107118, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34481920

RESUMO

A new approach is described for quantifying cholinergic receptor activation status human blood samples, based on M1 receptor-driven mobilization of intracellular calcium stores. The assay identifies anticholinergic as well as agonist cholinergic receptor activity. As a cell-based procedure, the assay shares the high efficiency of recently developed M1 receptor binding protocols, but differs from the latter in relying on fluorescence rather than radioactivity measurements. The assay targets a true functional effect insofar as it reflects a time-dependent process of net changes in activation of cholinergic receptors. Results from experiments with M1-expressing CHO cells exposed to a fluorogenic dye and the standard cholinergic agonist carbachol revealed the assay's ability to isolate pure agonist effects of clinical compounds as well as the net effects of serum containing agonist and antagonist factors. The new protocol thus provides two additional quantitative indices of cholinergic receptor activity in human serum, namely pure agonistic effects and net agonist/antagonist effects. As such, it could constitute a very useful addition to efforts to quantify global cholinergic status in human serum in various clinical conditions. By relying on fluorescence measures it should also prove much more accessible than radioactivity-based protocols.


Assuntos
Preparações Farmacêuticas , Radioatividade , Animais , Cálcio , Cricetinae , Cricetulus , Fluorescência , Humanos , Receptor Muscarínico M1
8.
Molecules ; 26(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34443384

RESUMO

Sentinel lymph node detection (SLND) is rapidly entering common practice in the management of patients with tumors. The introduction of mannose molecules to 99mTc-labeled dextrans, so far, showed that the sentinel node could trap these agents due to their recognition by the mannose receptors of lymph node macrophages. The current study aimed to synthesize, characterize, and biologically evaluate a series of mannosylated dextran derivatives labeled with 99mTc for potential use in SLND. The compounds were designed to have a dextran with a molecular weight of 10-500 kDa as a backbone, S-derivatized cysteines, efficient SNO chelators, and mannose moieties for binding to mannose receptors. They were successfully synthesized, thoroughly characterized using NMR techniques, and labeled with the fac-[99mTc(CO)3]+ synthon. Labeling with high yields and radiochemical purities was achieved with all derivatives. In vivo biodistribution and imaging studies demonstrated high uptake in the first lymph node and low uptakes in the following node and confirmed the ability to visualize the SLN. Among the compounds studied, 99mTc-D75CM demonstrated the most attractive biological features, and in combination with the high radiochemical yield and stability of the compound, its further evaluation as a new radiopharmaceutical for sentinel lymph node detection was justified.


Assuntos
Dextranos/química , Manose/química , Linfonodo Sentinela/patologia , Tecnécio/química , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Dextranos/síntese química , Imageamento Tridimensional , Injeções Intravenosas , Masculino , Manose/síntese química , Camundongos , Peso Molecular , Radioatividade , Compostos Radiofarmacêuticos/química , Distribuição Tecidual
9.
J Environ Radioact ; 237: 106707, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34364005

RESUMO

The article presents results of field studies at a site of radioactive waste storage and disposal facilities (the so-called LD RosRAO site, Sosnovy Bor, Leningrad region, Russia). The objective of the study is to overview the history and occurrence of groundwater contamination to answer the question whether the radioactive plume is historical (formed due to accidents, which happened at the beginning of the operations with the radioactive waste) or the release of radioactive solutions to groundwater is still occurring. The main method used to study the evolution of radioactive contamination is to analyze long-term observations of tritium, total alpha, and total beta activities in groundwater samples. The role of the hydrogeological conditions of the site, such as flow parameters, groundwater flow pattern, inter-aquifer downward groundwater leakage, and water-table fluctuations, in the evolution of contamination plumes has also been analyzed. In the field investigations, the integrity of the storage buildings to potential leaks was confirmed by different indirect methods. It was concluded that there is currently no significant release of radioactive components into groundwater at the LD RosRAO site and that the present conditions correspond to the stage of rehabilitation of the groundwater environment.


Assuntos
Água Subterrânea , Monitoramento de Radiação , Resíduos Radioativos , Radioatividade , Resíduos Radioativos/análise , Trítio
10.
J Environ Radioact ; 237: 106695, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34332827

RESUMO

This study describes and discusses the results of a 14 month-long campaign (April 2019 to June 2020) aimed at characterizing and quantifying the influence of environmental factors (cosmic rays, rainfall events, soil moisture and atmospheric radon) on airborne radiometric surveys, which are used for mapping the concentrations of potassium (K), uranium (U) and thorium (Th), or for monitoring the natural radioactivity in the environment. A large NaI(Tl) airborne spectrometer (4 down + 1 up detectors of 4 L) was installed at a height of 50 m on a meteorological tower to simulate an airborne hover at the Pyrenean Platform for Observation of the Atmosphere (P2OA) in Lannemezan. The continuous, high frequency acquisition of gamma-rays was accompanied by measurements of rainfall intensity, soil moisture content, atmospheric radon activity and meteorological parameters. A semi-diurnal cycle of apparent 232Th and 40K was observed and explained by atmospheric thermal tides. Both diurnal and seasonal cycles are also evident in the gamma-ray signal, mostly due to variations of soil moisture at these timescales with a maximum during summer when surface soil moisture (0-5 cm depth) is the lowest. An increase of 25% vol. of the soil moisture content, representing the range of variation between the end of summer (18% vol.) and the beginning of spring (43% vol.) leads to a decrease of gamma-rays in the K and Th window by the same amount. Conversely, these results illustrate the potential of using airborne gamma-ray spectrometry to monitor soil moisture at hectometer scales. The washout of radon-222 progeny during rainfall events influences the count of gamma-rays in the U window by adding an atmospheric component to the soil component. The amplitude of the signal increase in the U window varies with the precipitation rate and reaches 30% for an average event. By clear weather, atmospheric radon-222 volumic activity influences the count rate in the U window by about ±3.8% per Bq m-3, which translates into an influence of 148%/Bq m-3/kg Bq-1 (U). This comprehensive, multi-compartment approach is necessary to optimize and improve the processing and analysis of airborne gamma-ray spectrometry data for high sensitivity environmental studies. These results show the importance of environmental factors on the variability of gamma-ray spectrometry and the importance of taking them into account to accurately map radionuclides activities.


Assuntos
Monitoramento de Radiação , Radioatividade , Radônio , Poluentes Radioativos do Solo , Radiação de Fundo , Radioisótopos de Potássio/análise , Radônio/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
11.
Artigo em Inglês | MEDLINE | ID: mdl-34444512

RESUMO

In order to assess the radioactive level in the terrestrial and marine organisms in Yangjiang and the adjacent areas, 90Sr, gross beta and gamma-emitting radionuclides (238U, 226Ra, 228Th, 226Ra, 40K, 137Cs, 51Cr, 55Fe, 54Mn, 58Co, 60Co and 65Zn) were analyzed from 2011 to 2012. The annual effective doses were estimated in the high natural radioactive background areas in Yangjiang (HBRAYJ). The specific activities of 238U, 228Th, 226Ra, 40K and 137Cs in all organisms were <0.05-5.20, 0.30-14.50, 0.11-3.58, 11.1-148.0 and <0.003-0.088 Bq/kg, whilst 51Cr, 55Fe, 54Mn, 58Co, 60Co, 65Zn and 110mAg were below the minimum detectable activity. 90Sr and gross beta specific activities were 20.0-143.0 and 0.021-0.316 Bq/kg. Results show that 228Th was significantly higher than 238U and 226Ra of natural U series in organisms due to the rich-Th soils in the HBRAYJ; 228Th, 226Ra, 40K, 137Cs and 90Sr were greatly lower than the limited concentrations in Chinese foods. The internal dose mainly contributes to natural 40K, 226Ra and 228Th. It is useful to provide some basic data and assess the radiological risk from the HBRAYJ and Yangjiang nuclear power plants in future.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Poluentes Radioativos da Água , Organismos Aquáticos , China , Poluentes Radioativos do Solo/análise , Poluentes Radioativos da Água/análise
12.
Phys Med Biol ; 66(17)2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34378546

RESUMO

Purpose.To provide Monte Carlo calculated beam quality correction factors (kQ) for monoenergetic proton beams using the Monte Carlo codefluka.Materials and methods.The Monte Carlo codeflukawas used to calculate the dose absorbed in a water-filled reference volume and the air-filled cavities of six plane-parallel and four cylindrical ionization chambers. The chambers were positioned at the entrance region of monoenergetic proton beams with energies between 60 and 250 MeV. Based on these dose values,fQas well askQfactors were calculated whilefQ0factors were taken from Andreoet al(2020Phys. Med. Biol.65095011).Results. kQfactors calculated in this work were found to agree with experimentally determinedkQfactors on the 1%-level, with only two exceptions with deviations of 1.4% and 1.9%. The comparison offQfactors calculated usingflukawithfQfactors calculated using the Monte Carlo codesgeant4 andpenhshowed a general good agreement for low energies, while differences for higher energies were pronounced. For high energies, in most cases the Monte Carlo codesflukaandgeant4 lead to comparable results while thefQfactors calculated withpenhare larger.Conclusion.flukacan be used to calculatekQfactors in clinical proton beams. The divergence of Monte Carlo calculatedkQfactors for high energies suggests that the role of nuclear interaction models implemented in the different Monte Carlo codes needs to be investigated in more detail.


Assuntos
Prótons , Método de Monte Carlo , Radioatividade , Radiometria , Eficiência Biológica Relativa
13.
Mar Pollut Bull ; 172: 112795, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34391009

RESUMO

In this paper, a marine environmental sensitivity index system was constructed based on three factors: the marine biological species sensitivity, the marine ecological value sensitivity and the social and economic sensitivity. Combined with numerical simulations of 137Cs in the Beibu Gulf under the condition of a level-7 nuclear accident, a comprehensive risk assessment of marine radioactivity under the simulated accident in the Beibu Gulf was carried out. The results show that the areas at high risk and medium-to-high risk to marine radioactivity are mainly concentrated within 30 km of the Fangchenggang Nuclear Power Plant. The medium-risk areas are mainly distributed in sea areas within 30-50 km of the nuclear power plant, and the other sea areas are low-risk areas. The distribution of the risk sources and the characteristics of the regional tidal currents are the main factors affecting the magnitude and distribution of the comprehensive risk of regional marine radioactivity.


Assuntos
Radioatividade , Poluentes Químicos da Água , China , Monitoramento Ambiental , Medição de Risco , Poluentes Químicos da Água/análise
14.
Mar Pollut Bull ; 172: 112822, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34403925

RESUMO

Areas in central Norway were heavily contaminated with fallout from the Chernobyl accident in 1986. In this study, we assess 137Cs in surface sediments and sediment cores collected in the Vefsnfjord in Nordland county. Concentrations of 137Cs in surface sediments ranged from 159 to 191 Bq kg-1 dry weight (d.w.). Sub-surface peaks of 137Cs were observed in all cores, with a maximum concentration of 432 Bq kg-1 d.w. Given that little is known about the distribution of naturally occurring radionuclides in Norwegian fjords and coastal areas, a better understanding of the total burden of radioactivity is important for the Norwegian fishing and aquaculture industries. Therefore, analyses of the natural radionuclides 40K, 226Ra, 228Ra and 210Pb were included in the study. Analyses of total sulphur (TS), total carbon (TC), total organic carbon (TOC) and grain size distribution have been performed to provide a sedimentologic context for interpreting the radionuclide results.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos da Água , Estuários , Sedimentos Geológicos , Noruega , Poluentes Radioativos da Água/análise
15.
Artigo em Inglês | MEDLINE | ID: mdl-34299788

RESUMO

Various products containing a small number of added radionuclides are commonly available for use worldwide. However, frequent use of such products puts the public at risk of radiation exposure. In this study, dose assessments to members of the public using consumer products containing naturally occurring radioactive materials (NORMs) were conducted for various usage scenarios to evaluate the external and internal exposure dose. Data for this study were obtained from previous literature and were statistically analyzed using Boxplot to determine the input data for assessment. A normalized value of activity concentration was used for dose evaluation. In addition to other external and internal dose calculation codes, analytical calculations were used to perform age-dependent. Based on analytical calculations, the highest total effective dose equivalent (TEDE) received from necklace products at the upper whiskers with an activity concentration of 4.21 Bq/g for 238U, 24.4 Bq/g for 232Th, and 0.55 Bq/g for 40K for various age groups is 2.03 mSv/y for 1 year old, 1.24 mSv/y for 10 years old and 1.11 mSv/y for adult, which are above the international commission for radiation protection (ICRP) recommended public dose limit of 1 mSv/y. Results of external and internal exposure dose obtained using Microshield code, IMBA code and Visual Monte Carlo (VMC) code are all below the recommended public dose limit of 1 mSv/y.


Assuntos
Exposição à Radiação , Monitoramento de Radiação , Radioatividade , Adulto , Humanos , Lactente , Método de Monte Carlo , Doses de Radiação , Exposição à Radiação/análise , Radioisótopos/análise , República da Coreia
16.
Mar Pollut Bull ; 171: 112658, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34271507

RESUMO

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Egito , Sedimentos Geológicos , Oceano Índico , Radioisótopos de Potássio/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
17.
Radiat Prot Dosimetry ; 194(2-3): 178-185, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34218283

RESUMO

Novel building materials were manufactured and analyzed for 226Ra, 232Th and 40K using an HPGe gamma-ray spectrometer. The results show that the highest value of 40K was 4530 Bq per kg which was measured in a sample containing fly ashes from olive stones. The highest values of 226Ra and 232Th activities were 181 and 185 Bq per kg, which were measured in a sample with fly ashes from the co-combustion of coal and coke, respectively. On the other hand, the lowest values of 40K, 226Ra and 232Th activities were obtained for samples incorporating mussel shells. The radiological health hazard parameters, such as radium equivalent activity (Raeq), activity concentration index (I), absorbed and effective dose rates, associated with these radionuclides were evaluated. These values are within the EU recommended limits in building materials, except for samples of concrete containing fly ashes from olive stones, coal and coke. This study has contributed to the inclusion of industrial wastes that have not been collected previously in the Naturally Occurring Radioactive Material (NORM) databases on radioactivity of building materials.


Assuntos
Exposição à Radiação , Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Materiais de Construção , Radioisótopos de Potássio/análise , Doses de Radiação , Rádio (Elemento)/análise , Espanha , Tório/análise
18.
Chemosphere ; 285: 131444, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34265714

RESUMO

In this study, several natural radionuclides (40K, 238U, 235U, 228Ac) and their decay product were investigated in various invertebrate and vertebrate fossils. In the high radioactivity group of fossils, 238U and 235U concentrations increased from 141 to 3621 Bq/kg and from 5.4 to 167 Bq/kg, respectively. In the low radioactivity group of fossils, concentrations of both U isotopes increased from 4.6 to 51 Bq/kg and from 0.18 to 2.3 Bq/kg, respectively. High radioactivity has been linked to the phosphatization process that affected the uranium sorption. Scanning of electron microscope images and X-ray fluorescence analysis were used to confirm the mode of preservation of studied fossils and the presence of a correlation between the phosphorus content and uranium elements in fossil specimens.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Urânio , Fósseis , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise , Urânio/análise
19.
Biomed Instrum Technol ; 55(s3): 17-26, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34153999

RESUMO

Section 5.1.2 of ANSI/AAMI/ISO 11137-1 states that "the potential for induced radioactivity in product shall be assessed." This article describes how compliance with this requirement may be achieved using qualified test methods. Materials of consideration are conceptually discussed, and results of testing conducted on products processed with a 7.5-MeV X-ray irradiation process are provided. As X-ray becomes more widely used in healthcare sterilization, having standard assessment protocols for activation coupled with a shared database of material test results will benefit manufacturers seeking to utilize this innovative technology.


Assuntos
Radioatividade , Instalações de Saúde , Esterilização , Raios X
20.
PLoS One ; 16(6): e0250528, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34061865

RESUMO

Forming part of a study of radiological risk arising from use of radioactive consumer products, investigation is made of pendants containing naturally occurring radioactive material. Based on use of gamma-ray spectrometry and Monte Carlo (MC) simulations, the study investigates commercially available 'scalar energy pendants'. The doses from these have been simulated using MIRD5 mathematical phantoms, evaluation being made of dose conversion factors (DCFs) and organ dose. Metallic pendants code MP15 were found to contain the greatest activity, at 7043 ± 471 Bq from 232Th, while glass pendants code GP11 were presented the greatest 238U and 40K activity, at 1001 ± 172 and 687 ± 130 Bq respectively. MP15 pendants offered the greatest percentage concentrations of Th, Ce, U and Zr, with means of 25.6 ± 0.06, 5.6 ± 0.005, 1.03 ± 0.04 and 28.5 ± 0.08 respectively, giving rise to an effective dose of 2.8 mSv for a nominal wearing period of 2000 h. Accordingly, these products can give rise to annual doses in excess of the public limit of 1 mSv.


Assuntos
Materiais de Construção , Método de Monte Carlo , Imagens de Fantasmas , Doses de Radiação , Radioatividade , Espectrometria gama
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