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1.
Appl Radiat Isot ; 191: 110556, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36371867

RESUMO

The aim was to develop a web application for the estimation of the radioactivity contained in liquid and solid waste produced by in vitro nuclear medicine laboratories. Median percentages of solid and liquid waste were estimated from successive runs of 44 in vitro kits. This data was fed into a web-based app, which estimates the activity of the waste and provides detailed record keeping. Median liquid/solid waste percentages were 77%/23% for RIA and 95%/5% for IRMA assays. Total waste activities were below regulatory discharge limits.


Assuntos
Medicina Nuclear , Resíduos Radioativos , Radioatividade , Resíduos Sólidos , Laboratórios , Internet
2.
Appl Radiat Isot ; 191: 110528, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36379133

RESUMO

Research on unmanned online monitoring equipment for marine radioactivity surrounding nuclear power plants is of great significance. In this work, a small radioactivity monitoring system based on buoy was designed and manufactured for the emergency situation of nuclear accidents. The core of the radioactivity monitoring system is the underwater gamma spectrometer. The spectrometer can respond to gamma rays from 60 keV to 3 MeV, and can identify the nuclides whose characteristic rays belong to this energy range. The detection efficiency curve was calculated through Monte Carlo simulation and verified in a standard liquid source. A data acquisition processor was also designed to coordinate the detectors in the system and wirelessly transmit online monitoring data. Three experiments were carried out in the seawater around the Tianwan Nuclear Power Plant in Lianyungang, China using this online marine radioactivity monitoring system based on buoys. The stability and radioactivity monitoring capabilities of the system have been verified.


Assuntos
Monitoramento de Radiação , Radioatividade , Espectrometria gama/métodos , Raios gama , Monitoramento de Radiação/métodos , Método de Monte Carlo
3.
Environ Res ; 216(Pt 1): 114492, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36209792

RESUMO

BACKGROUND: Radon (222Rn) decay products can attach to particles in the air, be inhaled, and potentially cause airway damage. RESEARCH QUESTION: Is short-term exposure to particle radioactivity (PR) attributable to radon decay products emitted from particulate matter ≤2.5 µm in diameter (PM2.5) associated with pulmonary function in chronic obstructive pulmonary disease (COPD) patients? STUDY DESIGN AND METHODS: In this cohort study, 142 elderly, predominantly male patients with COPD from Eastern Massachusetts each had up to 4 one-week long seasonal assessments of indoor (home) and ambient (central site) PR and PM2.5 over the course of a year (467 assessments). Ambient and indoor PR were measured as α-activity on archived PM2.5 filter samples. Ratios of indoor/ambient PR were calculated, with higher ratios representing PR from an indoor source of radon decay. We also considered a measure of outside air infiltration that could dilute the concentrations of indoor radon decay products, the indoor/ambient ratio of sulfur concentrations in PM2.5 filter samples. Spirometry pre- and post-bronchodilator (BD) forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were conducted following sampling. Generalized additive mixed models were adjusted for meteorologic variables, seasonality, and individual-level determinants of pulmonary function. We additionally adjusted for indoor PM2.5 and black carbon (BC). RESULTS: PR exposure metrics indicating radon decay product exposure from an indoor source were associated with a reduction in FEV1 and FVC. Patients in homes with high indoor PR (≥median) and low air infiltration (

Assuntos
Poluentes Atmosféricos , Doença Pulmonar Obstrutiva Crônica , Radioatividade , Radônio , Humanos , Masculino , Idoso , Feminino , Produtos de Decaimento de Radônio , Poluentes Atmosféricos/análise , Estudos de Coortes , Material Particulado/análise , Fuligem , Exposição Ambiental/análise
4.
Sci Rep ; 12(1): 18919, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344543

RESUMO

The main objective of radiotherapy is to exploit the curative potential of ionizing radiation while inflicting minimal radiation-induced damage to healthy tissue and sensitive organs. Proton beam therapy has been developed to irradiate the tumor with higher precision and dose conformity compared to conventional X-ray irradiation. The dose conformity of this treatment modality may be further improved if narrower proton beams are used. Still, this is limited by multiple Coulomb scattering of protons through tissue. The primary aim of this work was to develop techniques to produce narrow proton beams and investigate the resulting dose profiles. We introduced and assessed three different proton beam shaping techniques: (1) metal collimators (100/150 MeV), (2) focusing of conventional- (100/150 MeV), and (3) focusing of high-energy (350 MeV, shoot-through) proton beams. Focusing was governed by the initial value of the Twiss parameter [Formula: see text] ([Formula: see text]), and can be implemented with magnetic particle accelerator optics. The dose distributions in water were calculated by Monte Carlo simulations using Geant4, and evaluated by target to surface dose ratio (TSDR) in addition to the transverse beam size ([Formula: see text]) at the target. The target was defined as the location of the Bragg peak or the focal point. The different techniques showed greatly differing dose profiles, where focusing gave pronouncedly higher relative target dose and efficient use of primary protons. Metal collimators with radii [Formula: see text] gave low TSDRs ([Formula: see text]) and large [Formula: see text]([Formula: see text]). In contrast, a focused beam of conventional ([Formula: see text]) energy produced a very high TSDR ([Formula: see text]) with similar [Formula: see text] as a collimated beam. High-energy focused beams were able to produce TSDRs [Formula: see text] and [Formula: see text] around 1.5 mm. From this study, it appears very attractive to implement magnetically focused proton beams in radiotherapy of small lesions or tumors in close vicinity to healthy organs at risk. This can also lead to a paradigm change in spatially fractionated radiotherapy. Magnetic focusing would facilitate FLASH irradiation due to low losses of primary protons.


Assuntos
Terapia com Prótons , Radioatividade , Prótons , Método de Monte Carlo , Aceleradores de Partículas , Dosagem Radioterapêutica
5.
Artigo em Inglês | MEDLINE | ID: mdl-36361445

RESUMO

Radiological aspects such as natural radioactivity of 238U, 232Th, 226Ra, 40K combined with potentially toxic metal(loid) (PTM) distribution features were seldom simultaneously investigated in rare earth element (REE) processing activities. This work was designed to investigate the distribution levels of natural radioactivity, air-absorbed dose rate of γ radiation as well as PTMs at a typical REE plant in Guangdong, China. Ambient soils around REE processing facilities were sampled, measured and assessed. The natural radioactivity of radionuclides of the samples was determined using a high-purity germanium γ-energy spectrometer while the air-absorbed dose rate of γ radiation was measured at a height of 1 m above the ground using a portable radiometric detector. The PTM content was measured by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the specific activities of the radionuclides ranged from 80.8 to 1990.2, 68.2 to 6935.0, 78.4 to 14,372.4, and 625.4 to 2698.4 Bq·kg-1 for 238U, 226Ra, 232Th, and 40K, respectively, representing overwhelmingly higher activity concentrations than worldwide soil average natural radioactivity. The radium equivalent activity and external hazard index of most samples exceeded the limits of 370 Bq·kg-1 and 1, respectively. The measured air-absorbed dose rate of γ radiation was in a range of 113~4004 nGy·h-1, with most sites displaying comparatively higher values than that from some other REE-associated industrial sites referenced. The content levels of PTMs of Cu, Ni, Zn, Mn, Pb, Cd, Cr, and As were 0.7~37.2, 1.8~16.9, 20.4~2070.5, 39.4~431.3, 2.3~1411.5, 0.1~0.7, 6.7~526.1, and 59.5~263.8 mg·kg-1, respectively. It is important to note that the PTM contents in the studied soil samples were 2.1~5.4 times higher for Zn-As and 1.4 times higher for Pb than the third level of the China soil standard while 2.5~13 times higher for Zn-As and 1.2 times higher for Pb than Canadian industry standard. The findings call for subsequent site remediation to secure the ecological environment and human health after the REE processing plant was decommissioned.


Assuntos
Metais Terras Raras , Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Humanos , Solo/química , Chumbo/análise , Canadá , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Radioisótopos/análise , Metais Terras Raras/análise , Monitoramento de Radiação/métodos , Espectrometria gama , Radioisótopos de Potássio/análise , Tório/análise
6.
Environ Monit Assess ; 195(1): 140, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36417000

RESUMO

Radiometric monitoring of construction materials is required for estimating the interior and exterior exposure to ionizing radiation emitted by terrestrial radioactive elements in building materials. Using gamma-ray spectroscopy, the activity concentrations of 226Ra, 232Th, and 40 K in fifty-two samples from eighteen different building materials commonly used in Erbil city, Kurdistan region, Iraq, were evaluated to assess possible radioactive dangers to human health. The activity concentrations of 226Ra, 232Th and 40 K ranged from 1 ± 0.1 (gypsum board) to 130 ± 11 (granite), 1.3 ± 0.2 (gypsum) to 66 ± 8 (ceramic sample), and 18.74 ± 4 (gypsum) to 1061.708 ± 40 (granite) with an average of 28 ± 5, 20.7 ± 4, and 340.8 ± 18 (average ± standard deviation), respectively. Radiological indicators (activity concentration index, alpha and gamma index, hazard indices, interior absorbed gamma dose rate and the corresponding yearly effective dosage rate, and excess lifetime cancer risk) were computed to assess the health risks associated with these building materials. Consideration was given to the indoor annual effective dosage for common construction materials, the radon surface expiration rate, and the indoor radon concentration. The mean values of activity concentration were then inputted into the RESRAD-BUILD computer software to calculate a resident's long-term radiation exposure. The dosages were measured over a range of 0 to 70 years. From 0 to 30 years, there was a significant change in dosages; however, from 30 to 70 years, the dosages were reasonably consistent. This research demonstrates that granite samples are not safe for dwellings with poor ventilation (especially those without windows). In general, other investigated construction materials in the buildings are deemed safe for the population, since the computed values for these parameters fall within the well-being restrictions or criterion values.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Radônio , Humanos , Radioisótopos de Potássio/análise , Tório/análise , Espectrometria gama , Rádio (Elemento)/análise , Sulfato de Cálcio/análise , Iraque , Monitoramento de Radiação/métodos , Materiais de Construção , Medição de Risco
7.
J Am Heart Assoc ; 11(20): e025470, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36197036

RESUMO

Background Although the effects of fine particulate matter (particulate matter ≤2.5 µm aerodynamic diameter [PM2.5]) on cardiovascular disease (CVD) morbidity and mortality are well established, little is known about the CVD health effects of particle radioactivity. In addition, there are still questions about which of the PM2.5 physical, chemical, or biological properties are mostly responsible for its toxicity. Methods and Results We investigated the association between particle radioactivity, measured as gross ß activity from highly resolved spatiotemporal predictions, and mortality for CVD, myocardial infarction, stroke, and all-cause nonaccidental mortality in Massachusetts (2001-2015). Within both difference-in-differences model and generalized linear mixed model frameworks, we fit both single-exposure and 2-exposure models adjusting for PM2.5 and examined the interaction between PM2.5 and gross ß activity. We found significant associations between gross ß activity and PM2.5 and each mortality cause. Using difference-in-differences and adjusting for PM2.5, we found the highest associations with myocardial infarction (rate ratio, 1.16 [95% CI, 1.08-1.24]) and stroke (rate ratio, 1.11 [95% CI, 1.04-1.18]) for an interquartile range increase (0.055 millibecquerels per cubic meter) in gross ß activity. We found a significant positive interaction between PM2.5 and gross ß activity, with higher associations between PM2.5 and mortality at a higher level of gross ß activity. We also observed that the associations varied across age groups. The results were comparable between the 2 statistical methods also with and without adjusting for PM2.5. Conclusions This is the first study that, using highly spatiotemporal predictions of gross ß-activity, provides evidence that particle radioactivity increases CVD mortality and enhances PM2.5 CVD mortality. Therefore, particle radioactivity can be an important property of PM2.5 that must be further investigated. Addressing this important question can lead to cost-effective air-quality regulations.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Doenças Cardiovasculares , Infarto do Miocárdio , Radioatividade , Acidente Vascular Cerebral , Humanos , Material Particulado/efeitos adversos , Material Particulado/análise , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Exposição Ambiental , Mortalidade
8.
Ann Nucl Med ; 36(12): 1010-1018, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36207497

RESUMO

OBJECTIVE: Semi-quantitative positron emission tomography (PET) values, such as the maximum standardized uptake value (SUVmax), are widely used to identify malignant lesions and evaluate the response to treatment. The image quality of ring-shaped dedicated breast positron emission tomography (dbPET) has been known to decrease the closer it is to the detector's edge. This study aimed to investigate the effect of radioactivity (RI) outside the detector field of view (FOV) on the image quality of the ring-shaped dbPET. METHODS: A breast phantom containing the left myocardium, which was prepared using a 3D printer, filled with 18F-fluorodeoxyglucose (FDG) solution with various RI concentration ratios (RCRs) of myocardium to background and scanned with the edge of an apex positioned exactly in line with the edge of the FOV of the dbPET scanner. The phantom image quality was visually and quantitatively evaluated. Following the phantom study, left-right breast differences (the left breast uptake ratio to the right breast (LUR)) on clinical dbPET images of 74 women were quantitatively evaluated. The relationships between these parameters, clinical indices, and FDG uptake in the left myocardium on PET/computed tomography (CT) images were analyzed. RESULTS: The phantom study showed that the higher the RCR of the myocardium and the closer it is to the top edge of the phantom, the higher is the pixel value of the dbPET images. In a clinical study, LUR was significantly correlated with myocardial SUVmax (r = 0.96, p < 0.0001) and metabolic myocardial volume (r = 0.63, p = 0.001) for whole-body PET/CT imaging. Although no significant correlations were found between LUR and age (r = 0.05, p = 0.6865), body mass index (r = 0.03, p = 0.8178), or distance between the left myocardial apex and chest wall (r = 0.16, p = 0.1667). CONCLUSIONS: FDG uptake in the myocardium affected dbPET images of the left breast, especially near the chest wall. Further, the effect of RI outside the FOV, such as in the myocardium, must be considered in the quantitative evaluation of breast cancer using dbPET.


Assuntos
Neoplasias da Mama , Radioatividade , Feminino , Humanos , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Mama/patologia
9.
J Radiol Prot ; 42(3)2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-36130529

RESUMO

Earth materials contain radionuclides of natural origin in varying concentrations. Exposure to natural sources dominates the occupational and public exposure to ionizing radiation. Canada has one of the largest and most diverse supplies of natural resources in the world. A large quantity of material production is associated with a large quantity of waste releases to the environment. Releases from industries involving naturally occurring radioactive material (NORM) can concentrate trace amounts of natural radionuclides and are often poorly characterized. This raises concerns for occupational and public health. Currently, there are data and knowledge gaps in radiological characteristics of NORM products and waste or releases to the environment. For the evaluation of occupational and public exposure to natural sources, a review of current inventory for major industries involving NORM in Canada was conducted with the objective to provide basic information on major issues, help set the priority for research needs to filling these data and knowledge gaps.


Assuntos
Resíduos Radioativos , Radioatividade , Canadá , Indústrias , Radiação Ionizante , Resíduos Radioativos/análise , Radioisótopos/análise
10.
Artigo em Inglês | MEDLINE | ID: mdl-36141963

RESUMO

It has been analyzed in this article the radioactivity concentrations of 226Ra, 232Th, 40K and radiological hazard parameters in different types of cements commonly used in Poland and available on the Polish market. The radiological hazard parameters are, in particular, absorbed gamma dose rate, annual effective dose, radium equivalent activity, the external hazard index, and the gamma and alpha indices. The radionuclide activities of the most important radionuclides 226Ra, 232Th, 40K have been determined by gamma-ray spectrometry with the use of two kinds of spectrometers of different operational parameters. One performed also measurements on 30-day and 45-day aged samples as to verify if there is a statistically significant difference in radioactivity concentration for shorter and longer aging time. The radioactivity concentrations in the cement samples ranged from 21.7-75.7 Bq·kg-1 for 226Ra, 12.3-47.3 Bq·kg-1 for 232Th to 123-430 Bq·kg-1 for 40K. The radiological parameters in cement samples were calculated as follows: mean radium equivalent activity Raeq = 127 Bq·kg-1, mean absorbed gamma dose rate D = 115 nGy·h-1, mean annual effective dose E = 570 µSv·y-1, external hazard index Hex = 0.32, internal hazard index Hin = 0.51, mean activity concentration index Iγ = 0.47 and mean alpha index Iα = 0.28. The results were compared with the reported data from other countries and the international standard values given by European Commission (EC) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000). Finally, thorough statistical analysis has been performed.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Materiais de Construção/análise , Polônia , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Radioisótopos/análise , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
11.
Artigo em Inglês | MEDLINE | ID: mdl-36078432

RESUMO

The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (Hex, Hin), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Raeq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core 232Th/238U mass fractions were determined from the obtained values of 238U, 232Th and 40K for the examined rocks of Seih-Sidri area. The average 238U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one's radiological health.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Urânio , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Radioisótopos/análise , Saúde Radiológica , Rádio (Elemento)/análise , Poluentes Radioativos do Solo/análise , Tório/análise , Urânio/análise
12.
Artigo em Inglês | MEDLINE | ID: mdl-36078754

RESUMO

In this article, an investigation of the natural radioactivity content of pyroclastic products from Mt. Etna, eastern Sicily, Southern Italy, was carried out. In particular, the assessment of the average activity concentration of the investigated radionuclides, related to the mineralogical phase composition of the analyzed samples, and the radiological health risk for the population, was performed. High Purity Germanium (HPGe) gamma-ray spectrometry was employed in order to quantify the average specific activity of 226Ra, 232Th, and 40K natural radioisotopes. The absorbed gamma dose rate (D), the radium equivalent activity (Raeq), the hazard indices (Hin and Hex), the annual effective dose equivalent outdoor (AEDEout), and the excess lifetime cancer risk (ELCR) were also estimated in order to assess any possible radiological hazard for the population. In our case, they were found to be lower than the maximum recommended values for the population members, thus reasonably excluding radiological hazard effects. Moreover, the identification of the source of the aforementioned naturally occurring radionuclides was attempted by X-ray Diffraction (XRD) and Micro-Raman Scattering (MRS), thereby recognizing the main radioisotope-bearing minerals present in the investigated pyroclastic products. Finally, Pearson correlation, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were performed by processing observed radioactivity and radiological parameters in order to determine their correlation with the sampling locations.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Radioisótopos de Potássio/análise , Monitoramento de Radiação/métodos , Radioisótopos/análise , Rádio (Elemento)/análise , Sicília , Poluentes Radioativos do Solo/análise , Espectrometria gama , Tório/análise
13.
Kaku Igaku ; 59(1): 51-55, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-36104246

RESUMO

OBJECTIVE: [177Lu]Lu-PSMA-617 is a radioisotope used in nuclear medicine. It is necessary to take appropriate measures to limit its exposure and ensures its airborne concentrations do not exceed legally permitted levels. Therefore, the purpose of this study was to measure the airborne radioactivity concentration in the inpatient room after administering [177Lu]Lu-PSMA-617 to humans. METHODS: Three males with advanced prostate-specific membrane antigen (PSMA)-positive metastatic castration resistant prostate cancer were intravenously administered [177Lu]Lu-PSMA-617 (7.4 GBq ± 10%) in an inpatient room, and the airborne radioactivity concentrations were measured at two locations in the room (in the center of the room and at the bedside) using a filter collection method. RESULTS: After administration of [177Lu]Lu-PSMA-617, the airborne radioactivity concentrations measured were below the limit of detection (1.1 × 10-6 Bq/cm3 or 9.5 × 10-7 Bq/cm3) in all three humans, and all concentrations were consistently below the standard value of 1/10,000 of 2 × 10-2 Bq/cm3, the legal airborne concentration limit of 177Lu. CONCLUSION: The results of this study confirmed that the airborne concentration of [177Lu]Lu-PSMA-617 after administration to humans was below the legally permitted level.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Radioatividade , Dipeptídeos , Compostos Heterocíclicos com 1 Anel , Humanos , Pacientes Internados , Lutécio , Masculino , Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração/patologia , Neoplasias de Próstata Resistentes à Castração/radioterapia
14.
J Environ Radioact ; 253-254: 106991, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36084569

RESUMO

The article highlights the results of a radioecological survey of the surface areas of combat boreholes at the Sary-Uzen site located on the territory of the Semipalatinsk Test Site (STS), where underground nuclear tests in these boreholes were conducted earlier. The surface areas of boreholes were examined the levels of radioactive contamination of the soil were determined. A total of 2 main groups were identified. The first group includes boreholes with radioactive contamination of the soil on the surface area. The second group includes boreholes with no radioactive contamination of the surface soil layer. The first group can be divided into boreholes with a deformation of the ground surface and without it. For each variety, depending on the specifics of the nuclear test, the characteristic features of radioactive contamination were determined. Based on the results of the survey, the ranges of specific activity values were established.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Cazaquistão , Monitoramento de Radiação/métodos , Solo , Poluentes Radioativos do Solo/análise
15.
Appl Radiat Isot ; 189: 110422, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36049442

RESUMO

It is well known that George Hevesy and Hilde Levi were the original discoverers of neutron activation analysis. However, there were many other researchers in Europe that firstly unknowingly and knowingly discovered the neutron, and others who experimented in neutron induced radioactivity. A historical timeline of the several parallel experiments in a very short period is given in this synopsis. It eventually was Hevesy and Hilde to first use the powerful technique of neutron activation analysis for analytical chemistry.


Assuntos
Nêutrons , Radioatividade , Europa (Continente) , Análise de Ativação de Nêutrons/métodos
16.
J Radiol Prot ; 42(3)2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-36053136

RESUMO

A prototype tool has been developed for deriving sediment distribution coefficients,Kd, in the marine environment by harvesting simultaneous measurements of activity concentrations of radionuclides in seawater and sediments based on the International Atomic Energy Agency's Marine Radioactivity Information System (MARIS). As a case study, theKdvariability in the Baltic Sea was investigated as this region has been extensively monitored by HELCOM since 1984 resulting in a comprehensive dataset with good spatial and temporal coverage and required ancillary parameters. The prototype tool was used to derive a dataset ofin-situapparentKd(a)values derived from measurements of seawater and sediment in quasi-equilibrium conditions from the Baltic Sea over a period of approximately 35 years. For Cs, a comprehensive analysis of the Baltic SeaKd(a)dataset was undertaken, focusing on the temporal trend ofKd(a)and comparing the results toKdvalues derived elsewhere. For Sr and Pu, for which there were fewer data records available a more rudimentary analysis was carried out. The CsKd(a)median values derived from137Cs data in this study were estimated to be 2154 l kg-1for seabed sediment and 10 000 l kg-1for suspended sediment. The value derived for seabed sediment is in good agreement with the previously recommended ocean margin CsKdvalue of 4000 l kg-1. The analysis demonstrated the important distinction in the Baltic Sea betweenKdvalues for seabed sediment and suspended sediments, which differed by an order of magnitude. The analysis also highlighted the dependence ofKdvalues on the variation in both the salinity of seawater and the type of seabed sediment. Such variability can significantly influence outcomes when modelling the behaviour of radionuclides in marine dispersion modelling.


Assuntos
Radioatividade , Poluentes Radioativos da Água , Sedimentos Geológicos , Sistemas de Informação , Água do Mar , Poluentes Radioativos da Água/análise
17.
Radiat Environ Biophys ; 61(4): 597-608, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36175773

RESUMO

Proper documentation of baseline radiation data of different environments is an important step toward adequate environmental monitoring, and it provides quick means to quantitatively check and determine possible radionuclide contamination by anthropogenic sources. Besides, such documentation is useful for decision making processes, assessment of dose rates to the public, epidemiological studies, and environmental regulations. This review summarizes the results of studies conducted on radioactivity in Nigerian environments. For most soil samples, the levels of radioactivity are well within the world averages of 33, 45, and 420 Bq kg-1 for 226Ra, 232Th and 40K, respectively. Other soil samples from regions such as Abeokuta in the southwest, and Jos in the northcentral have been described as high background radiation areas with radioactivity values comparable with those obtained from known high background radiation areas such as the Odisha (formerly Orissa) coast in India (with values reported as 350, 2,825, and 180 Bq kg-1 for 238U/226Ra, 232Th, and 40K, respectively). In some parts of Nigeria, surface and underground water sources used for drinking and other purposes also present elevated levels of 226Ra above the world range of 0.01 to 0.1 Bq l-1 and the tolerable levels recommended by the World Health Organization and U.S. Environmental Protection Agency. Corresponding radiation doses due to measured radioactivities from different environments were estimated and compared with those reported in similar studies around the world. More so, the human and environmental health hazards that might be associated with the reported radioactivity in different environmental settings are discussed. The present report is expected to support authorities in developing appropriate regulations to protect the public from radiation exposure arising from environmental radioactivity. The report also examines other areas of consideration for future studies to ensure adequate radiation monitoring in Nigeria.


Assuntos
Monitoramento de Radiação , Radioatividade , Rádio (Elemento) , Poluentes Radioativos do Solo , Humanos , Radioisótopos de Potássio/análise , Poluentes Radioativos do Solo/análise , Tório/análise , Nigéria , Doses de Radiação , Radiação de Fundo , Monitoramento de Radiação/métodos , Solo , Rádio (Elemento)/análise
18.
Artigo em Inglês | MEDLINE | ID: mdl-36011815

RESUMO

In the context of the rapid development of the world's nuclear power industry, it is necessary to establish background data on radionuclides of different samples from different regions, and the premise of obtaining such basic data is to have a series of good sample processing and detection methods. The radiochemical analysis methods of low-level radionuclides 137Cs (Cesium) in environmental and biological samples are introduced and reviewed in detail. The latest research progress is reviewed from the five aspects of sample pretreatment, determination, separation, calculation, application of radioactive cesium and the future is proposed.


Assuntos
Radioatividade , Poluentes Radioativos do Solo , Radioisótopos de Césio/análise , Poluentes Radioativos do Solo/análise
19.
J Environ Radioact ; 251-252: 106979, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35963215

RESUMO

Scale residues can accumulate on the interior surfaces of subsea petroleum pipes and may incorporate naturally occurring radioactive materials (NORM). The persistent nature of 'NORM scale' may result in a radiological dose to the organisms living on or near intact pipelines. Following a scenario of in-situ decommissioning of a subsea pipeline, marine organisms occupying the exteriors or interiors of petroleum structures may have close contact with the scale or other NORM-associated contaminated substances and suffer subsequent radiological effects. This case study used radiological dose modelling software, including the ERICA Tool (v2.0), MicroShield® Pro and mathematical equations, to estimate the likely radiological doses and risks of effects from NORM-contaminated scale to marine biota from a decommissioned offshore oil and gas pipeline. Using activity concentrations of NORM (226Ra, 210Po, 210Pb, 228Ra, 228Th) from a subsea pipeline from Australia, environmental realistic exposure scenarios including radiological exposures from both an intact pipe (external only; accounting for radiation shielding by a cylindrical carbon steel pipe) and a decommissioned pipeline with corrosive breakthrough (resulting in both internal and external radiological exposure) were simulated to estimate doses to model marine organisms. Predicted dose rates for both the external only exposure (ranging from 26 µGy/h to 33 µGy/h) and a corroded pipeline (ranging from 300 µGy/h to 16,000 µGy/h) exceeded screening levels for radiological doses to environmental receptors. The study highlighted the importance of using scale-specific solubility data (i.e., Kd) values for individual NORM radionuclides for ERICA assessments. This study provides an approach for conducting marine organism dose assessments for NORM-contaminated subsea pipelines and highlights scientific gaps required to undertake risk assessments necessary to inform infrastructure decommissioning planning.


Assuntos
Petróleo , Monitoramento de Radiação , Radioatividade , Organismos Aquáticos , Biota , Monitoramento de Radiação/métodos , Medição de Risco
20.
J Environ Radioact ; 251-252: 106982, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35964526

RESUMO

The drilling mud from in situ leaching uranium mining is a type of low-radioactivity waste that contains natural nuclides and other harmful substances. In order to determine whether the drilling mud can meet the requirements of radioactive exemption management standards, field investigations and data simulations were conducted in this study. Two typical uranium mines were selected for onsite investigations. Drilling mud from different layers (i.e., the upper covering layer and ore-bearing layer) and from different stages (e.g., logging stage mud, drilling expansion stage mud, and mixed mud) was sampled. For each sample, the 238U and 226Ra concentrations of the solid components and the U and 226Ra concentrations of the supernatant were analyzed. The results revealed that the highest 238U and 226Ra concentrations of the solid components were 4122 Bq/kg and 4077 Bq/kg, while the 238U and 226Ra concentrations of the mixed drilling mud were all less than 300 Bq/kg. A radioactivity estimation model was established for scenario analysis. Exemption management screening lines of waste drilling mud, which can be used to classify and treat the drilling project according to the deposit's grade and conditions, were proposed for in situ leaching drilling projects.


Assuntos
Monitoramento de Radiação , Radioatividade , Poluentes Radioativos do Solo , Urânio , Mineração , Poluentes Radioativos do Solo/análise , Urânio/análise
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