1,281 results
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2. Preparation of paper scintillator for detecting 3H contaminant.
- Author
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Miyoshi H and Ikeda T
- Subjects
- Beta Particles, Hydrogen analysis, Scintillation Counting instrumentation, Silicon Dioxide chemistry
- Abstract
Liquid scintillator (LS)-encapsulated silica was prepared by the sol-gel method and then was added dropwise onto a wipe paper to form a paper scintillator. First, the efficiencies of wipe were determined for both the paper scintillator and the wipe paper using a liquid scintillation counter (LSC). The efficiencies of wipe using the paper scintillator and the wipe paper were 88 and 36 %, respectively. The detection efficiencies were 5.5 % for the paper scintillator, 46 % for the wipe paper using an LS and 0.08 % for the (3)H/(14)C survey meter, respectively, compared with that of a melt-on scintillator of 47 %. Second, an (3)H contaminant on the paper scintillator was successfully detected using a photomultiplier without an LSC or an (3)H/(14)C survey meter. Finally, the paper scintillator was able to detect beta rays of the (3)H contaminant easily without an LS.
- Published
- 2013
- Full Text
- View/download PDF
3. ALIGNING VIDEO-AND STRUCTURED DATA FOR IMAGING OPTIMISATION
- Author
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Charlotta Lundh, Magnus Båth, Mårten Falkenberg, Jonas Ivarsson, and Anja Almen
- Subjects
Paper ,Diagnostic Imaging ,Radiation ,Information retrieval ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,Computer science ,business.industry ,Process (engineering) ,Data management ,Scale (chemistry) ,Public Health, Environmental and Occupational Health ,Video Recording ,Qualitative property ,Context (language use) ,General Medicine ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Workflow ,Work (electrical) ,030220 oncology & carcinogenesis ,Radiology, Nuclear Medicine and imaging ,business - Abstract
Imaging optimisation can benefit from combining structured data with qualitative data in the form of audio and video recordings. Since video is complex to work with, there is a need to find a workable solution that minimises the additional time investment. The purpose of the paper is to outline a general workflow that can begin to address this issue. What is described is a data management process comprising the three steps of collection, mining and contextualisation. This process offers a way to work systematically and at a large scale without succumbing to the context loss of statistical methods. The proposed workflow effectively combines the video and structured data to enable a new level of insights in the optimisation process.
- Published
- 2021
4. ACCURACY OF CT NUMBERS OBTAINED BY DIRA AND MONOENERGETIC PLUS ALGORITHMS IN DUAL-ENERGY COMPUTED TOMOGRAPHY
- Author
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Michael Sandborg, Alexandr Malusek, Lilian Henriksson, Åsa Carlsson Tedgren, Maria Magnusson, and Gudrun Alm Carlsson
- Subjects
Physics ,Paper ,Scanner ,Radiation ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,Phantoms, Imaging ,Attenuation ,Public Health, Environmental and Occupational Health ,Dual-Energy Computed Tomography ,General Medicine ,Radiotherapy treatment planning ,Imaging phantom ,Radiography, Dual-Energy Scanned Projection ,Hounsfield scale ,Absorbed dose ,Beam Hardening Artifact ,Radiology, Nuclear Medicine and imaging ,Radiologi och bildbehandling ,Tomography, X-Ray Computed ,Algorithm ,Algorithms ,Radiology, Nuclear Medicine and Medical Imaging ,Iodine - Abstract
Dual-energy computed tomography (CT) can be used in radiotherapy treatment planning for the calculation of absorbed dose distributions. The aim of this work is to evaluate whether there is room for improvement in the accuracy of the Monoenergetic Plus algorithm by Siemens Healthineers. A Siemens SOMATOM Force scanner was used to scan a cylindrical polymethyl methacrylate phantom with four rod-inserts made of different materials. Images were reconstructed using ADMIRE and processed with Monoenergetic Plus. The resulting CT numbers were compared with tabulated values and values simulated by the proof-of-a-concept algorithm DIRA developed by the authors. Both the Monoenergetic Plus and DIRA algorithms performed well; the accuracy of attenuation coefficients was better than about ±1% at the energy of 70 keV. Compared with DIRA, the worse performance of Monoenergetic Plus was caused by its (i) two-material decomposition to iodine and water and (ii) imperfect suppression of the beam hardening artifact in ADMIRE. Funding: CancerfondenSwedish Cancer Society [CAN 2017/1029, CAN 2018/622]; Swedish state government [LiO-602731]; Swedish county councils, the ALF-agreement [LiO-602731]; Patientsakerhetsforskning Region Ostergotland [LiO-724181]; VetenskapsradetSwedish Research Council [VR-NT 2016-05033]
- Published
- 2021
5. QUANTIFICATION OF PULMONARY PATHOLOGY IN CYSTIC FIBROSIS–COMPARISON BETWEEN DIGITAL CHEST TOMOSYNTHESIS AND COMPUTED TOMOGRAPHY
- Author
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K Vult von Steyern, Åse A. Johnsson, Magnus Båth, Rauni Rossi Norrlund, M. Gilljam, Carin Meltzer, and Jenny Vikgren
- Subjects
Paper ,Cystic Fibrosis ,Computed tomography ,Cystic fibrosis ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Pulmonary pathology ,Lung ,Rank correlation ,Radiation ,Bronchiectasis ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Public Health, Environmental and Occupational Health ,Digital Chest Tomosynthesis ,Reproducibility of Results ,General Medicine ,medicine.disease ,Tomosynthesis ,Radiography ,030228 respiratory system ,Lung disease ,business ,Nuclear medicine ,Tomography, X-Ray Computed - Abstract
Purpose: Digital tomosynthesis (DTS) is currently undergoing validation for potential clinical implications. The aim of this study was to investigate the potential for DTS as a low-dose alternative to computed tomography (CT) in imaging of pulmonary pathology in patients with cystic fibrosis (CF). Methods: DTS and CT were performed as part of the routine triannual follow-up in 31 CF patients. Extent of disease was quantified according to modality-specific scoring systems. Statistical analysis included Spearman’s rank correlation coefficient (r) and Krippendorff’s alpha (α). Major findings: The median effective dose was 0.14 for DTS and 2.68 for CT. Intermodality correlation was very strong for total score and the subscores regarding bronchiectasis and bronchial wall-thickening (r = 0.82–0.91, P
- Published
- 2021
6. APPLICATION OF TIME-AVERAGED AND INTEGRAL-BASED MEASURE FOR MEASUREMENT RESULTS VARIABILITY REDUCTION IN GSM/DCS/UMTS SYSTEMS
- Author
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Darko S. Suka, Predrag Pejovic, and Mirjana Simić-Pejović
- Subjects
Paper ,Radio Waves ,Measure (physics) ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Computer Communication Networks ,0302 clinical medicine ,Electromagnetic Fields ,GSM ,Radiation Monitoring ,EMF exposure levels ,Temporal EMF variations ,Long-term measurements ,Time-averaging ,Power density ,Integral-based measure ,Statistics ,Outcome Assessment, Health Care ,Metre ,Humans ,Radiology, Nuclear Medicine and imaging ,Exposure assessment ,Radiation ,Radiological and Ultrasound Technology ,Public Health, Environmental and Occupational Health ,General Medicine ,Repeatability ,Environmental Exposure ,Data set ,030220 oncology & carcinogenesis ,Environmental science ,Radio wave - Abstract
Since EMF levels from wireless telecommunication networks are non-stationary and exhibit large temporal variations, the use of continuous measurements during extended periods (preferably 24 h or longer) with a data-logging system is required. Because of the short-term variations of E field, the 6-min measurements and 6-min averaged results to obtain the mean level strength at a given place appear to be dependent on the time of measurements during the day. This paper presents a new (integral- based) measure to evaluate electromagnetic exposure. The new measure is a pure physical descriptor of the amount of exposed energy density (a parameter accumulated from instantaneous power density values in time). To confirm previous observations, continuous measurements with personal exposure metre were recorded 24 h a day for two weeks at every location in urban area, 14 different locations in total. Additionally, to check temporal variations and repeatability of exposure assessment, a week of prolonged measurements was taken 6 months later, making in total three weeks of measurements at 2 locations. Day-to-day repeatability of RF-EMF exposure was analysed through the time-averaged and integral-based measure. The analysis is based on approximately 5.1 million data samples (1.7 million for each band). The ratio between the maximum and minimum instantaneous (maximum and minimum 6-min averaged) E field values during the day could reach up to 25 dB (20 dB). Therefore, great variability in the results may occur. By applying the 24 h time-averaged and integral-based measure on a 24 h data set of measurements, the variability of daily exposure could stay within ±20% of the week mean level obtained either with the time-averaged or integral-based measure. Both, the time-averaged E field and integral-based power density exposures of the general public in all locations were found to be well below the general public exposure limits of the ICNIRP guidelines.
- Published
- 2019
7. TO USE OR NOT USE PATIENT SHIELDING ON PREGNANT WOMEN UNDERGOING CT PULMONARY ANGIOGRAPHY: A PHANTOM STUDY
- Author
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Anetta Bolejko, Dino Begano, and Marcus Söderberg
- Subjects
Paper ,Radiation Dosage ,Effective dose (radiation) ,030218 nuclear medicine & medical imaging ,Ionizing radiation ,03 medical and health sciences ,0302 clinical medicine ,Pregnancy ,Pulmonary angiography ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Automatic exposure control ,Fetus ,Radiation ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Phantoms, Imaging ,Public Health, Environmental and Occupational Health ,Angiography ,General Medicine ,medicine.disease ,Pulmonary embolism ,030220 oncology & carcinogenesis ,Absorbed dose ,Female ,Pregnant Women ,Nuclear medicine ,business ,Tomography, X-Ray Computed - Abstract
Pregnancy increases the risk of pulmonary embolism. Computed tomography pulmonary angiography (CTPA) is used for diagnosis. CT generates ionising radiation, and thus, abdominal shielding may be used. This phantom study investigated the effects of patient shielding and scan length reduction on the fetal and maternal ionising radiation dose from CTPA. The absorbed dose to the fetus was measured using thermoluminescent dosemeters. Estimated effective doses to the pregnant patient were based on the dose-length products. Shielding increased both the effective dose to the patient by 47% and the mean absorbed dose to the fetus (0.10 vs. 0.12 mGy; p
- Published
- 2020
8. RISK EVALUATION IN THE LOW-DOSE RANGE CT FOR RADIATION-EXPOSED CHILDREN, BASED ON DNA DAMAGE
- Author
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Martina Horváthová, Lenka Jánošíková, Dušan Šalát, D. Nikodemova, Andrej Klepanec, and Martina Juričeková
- Subjects
Paper ,medicine.medical_specialty ,Adolescent ,DNA damage ,Radiation Dosage ,Chromosome aberration ,Risk Assessment ,Chromosomes ,030218 nuclear medicine & medical imaging ,Histones ,03 medical and health sciences ,0302 clinical medicine ,Epidemiology ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,DNA Breaks, Double-Stranded ,Medical diagnosis ,Child ,Radiometry ,Chromosome Aberrations ,Radiation ,Micronucleus Tests ,Radiological and Ultrasound Technology ,business.industry ,Low dose ,Public Health, Environmental and Occupational Health ,Infant ,General Medicine ,DNA ,Risk evaluation ,030220 oncology & carcinogenesis ,Child, Preschool ,Micronucleus test ,Biological Assay ,Tomography ,Radiology ,business ,Tomography, X-Ray Computed ,DNA Damage - Abstract
One of the most common usages of radiation in current medical diagnosis is computed tomography (CT) using X-rays. The potential health risk of CT scans has been discussed in various studies to determine whether low-dose radiation from CT could enhance the chromosome aberration yields in pediatric patients and increase their risk of carcinogenesis. For this reason, it is of great interest to study the effects of low-dose radiation. The induction of DNA damage by a CT scan examination has been demonstrated in several reports by the γ-H2AX assay, the micronuclei assay and dicentrics measurements. However, the results of most studies showed limitations. On the other hand, epidemiological studies give contradictory results for post-natal radiation exposure in the low-dose range, so it is still difficult to draw conclusions about the effects of CT examinations and risk of carcinogenesis. This article provides an overview of previously published data and summarizes the current state of knowledge.
- Published
- 2019
9. Optimization of Lung CT Protocol for the Diagnostic Evaluation of Covid-19 Lung Disease
- Author
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Mohammad Reza Ahangaran, Saeed Nasiri, Seyed Mohammad Bagher Hosseini Nasab, Mina Morshedi, Roghaye Rahimi, and Mohammad Reza Deevband
- Subjects
musculoskeletal diseases ,Paper ,Lung Diseases ,Coronavirus disease 2019 (COVID-19) ,Image quality ,Diagnostic evaluation ,Iran ,Radiation Dosage ,Effective dose (radiation) ,Tube current modulation ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Lung ,Protocol (science) ,Radiation ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,business.industry ,SARS-CoV-2 ,fungi ,Public Health, Environmental and Occupational Health ,COVID-19 ,General Medicine ,Lung disease ,Data collecting ,Nuclear medicine ,business ,Tomography, X-Ray Computed - Abstract
This study intends to evaluate the different lung CT scan protocols used for the diagnostic evaluation of COVID-19-induced lung disease in Iranian imaging centers in terms of radiation dose and image quality. After data collecting, subjective image quality, radiation dose and objective image quality such as noise, SNR and CNR were assessed. Statistically significant differences in effective dose and image quality were evident among different lung CT protocols. Lowest and highest effective dose was1.31 ± 0.53 mSv related to a protocol with activated AEC (reference mAs = 20) and 6.15 ± 0.57 mSv related to a protocol with Fixed mAs (mAs = 100), respectively. A protocol with enabled tube current modulation with 70 mAs as a reference mAs, and protocol with 20 mAs and enabled AEC had the best and lowest image quality, respectively. To optimize the scan parameters, AEC must be used, and a range of tube currents (between 20 and 50 mAs) can produce acceptable images in terms of diagnostic quality and radiation dose for the diagnosis of COVID-19-induced lung disease.
- Published
- 2021
10. Practical Challenges with Imaging Covid-19 in Brazil: Mitigation in and Beyond the Pandemic
- Author
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Luiz Cláudio de Moura Carvalho, Shadi Ebrahimian, Juliana Santana de Melo Tapajós, Ricardo Varella, Mannudeep K. Kalra, Fatemeh Homayounieh, Helen J. Khoury, and Mônica Oliveira Bernardo
- Subjects
Paper ,medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,MEDLINE ,Computed tomography ,Radiation Dosage ,Pandemic ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,Medical physics ,Prospective Studies ,Pandemics ,Retrospective Studies ,Radiation ,AcademicSubjects/SCI00180 ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,SARS-CoV-2 ,Public Health, Environmental and Occupational Health ,Ethics committee ,COVID-19 ,Retrospective cohort study ,General Medicine ,Frequent use ,business ,Brazil - Abstract
Computed tomography (CT) provides useful information in patients with known or suspected COVID-19 infection. However, there are substantial variations and challenges in scanner technologies and scan practices that have negative effect on the image quality and can increase radiation dose associated with CT. Objective: In this article, we present major issues and challenges with use of CT at five Brazilian CT facilities for imaging patients with known or suspected COVID-19 infection and offer specific mitigating strategies. Methods: Observational, retrospective and prospective study of five CT facilities from different states and regions of Brazil, with approval of research and ethics committees. Results: The most important issues include frequent use of CT, lack of up-to-date and efficient scanner technologies, over-scanning and patient off-centring. Mitigating strategies can include updating scanner technology and improving scan practices.
- Published
- 2021
11. THE GERMAN DOSE RATE MONITORING NETWORK AND IMPLEMENTED DATA HARMONIZATION TECHNIQUES
- Author
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W. Harms, I. Hellmann, F. Weiler, M. Bleher, H. Dombrowski, R. Luff, H. Doll, U. Stöhlker, S Seifert, and B. Prommer
- Subjects
Paper ,Quality management ,Computer science ,Population ,Radiation Dosage ,030218 nuclear medicine & medical imaging ,German ,03 medical and health sciences ,0302 clinical medicine ,Radiation Protection ,Radiation Monitoring ,Humans ,Radiology, Nuclear Medicine and imaging ,education ,education.field_of_study ,Radiation ,Radiological and Ultrasound Technology ,Warning system ,business.industry ,Public Health, Environmental and Occupational Health ,General Medicine ,language.human_language ,Europe ,Data exchange ,030220 oncology & carcinogenesis ,language ,Systems engineering ,Radiation monitoring ,Radiation protection ,business ,Quality assurance ,Software ,Radioactive Pollutants - Abstract
Environmental radiation monitoring networks have been established in Europe and world-wide for the purpose of protecting population and environment against ionizing radiation. Some of these networks had been established during the cold war period and were improved after the Chernobyl accident in 1986. Today, the German Federal Office for Radiation Protection (BfS) operates an early warning network with roughly 1800 ambient dose equivalent rate (ADER) stations equally distributed over the German territory. The hardware and software of all network components are developed in-house allowing the continuous optimization of all relevant components. A probe characterization and quality assurance and control program are in place. Operational and technical aspects of the network and data harmonization techniques are described. The latter allows for calculating of the terrestrial and net ADER combined with uncertainties mainly from site specific effects. Harmonized data are finally used as input to the German emergency management system and the European radiological data exchange platform.
- Published
- 2018
12. Exposure to Radiofrequency Electromagnetic Fields From Wi-Fi in Australian Schools
- Author
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Ken Karipidis, Rick Tinker, Don Wijayasinghe, Stuart Henderson, and Lydiawati Tjong
- Subjects
Electromagnetic field ,Paper ,Rf exposure ,Radio Waves ,010501 environmental sciences ,01 natural sciences ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Base station ,0302 clinical medicine ,Electromagnetic Fields ,Environmental health ,Humans ,Radiology, Nuclear Medicine and imaging ,Child ,0105 earth and related environmental sciences ,Radiation ,Schools ,Radiological and Ultrasound Technology ,Public Health, Environmental and Occupational Health ,Australia ,Public concern ,General Medicine ,Environmental exposure ,Environmental Exposure ,Environmental science ,Cell Phone ,Radio wave - Abstract
The increasing use of Wi-Fi in schools and other places has given rise to public concern that the radiofrequency (RF) electromagnetic fields from Wi-Fi have the potential to adversely affect children. The current study measured typical and peak RF levels from Wi-Fi and other sources in 23 schools in Australia. All of the RF measurements were much lower than the reference levels recommended by international guidelines for protection against established health effects. The typical and peak RF levels from Wi-Fi in locations occupied by children in the classroom were of the order of 10−4 and 10−2% of the exposure guidelines, respectively. Typical RF levels in the classroom were similar between Wi-Fi and radio but higher than other sources. In the schoolyard typical RF levels were higher for radio, TV and mobile phone base stations compared to Wi-Fi. The results of this study showed that the typical RF exposure of children from Wi-Fi at school is very low and comparable or lower to other sources in the environment.
- Published
- 2017
13. THE POTENTIATION OF THE RADIOPROTECTIVE EFFICACY OF TWO MEDICAL COUNTERMEASURES, GAMMA-TOCOTRIENOL AND AMIFOSTINE, BY A COMBINATION PROPHYLACTIC MODALITY
- Author
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Vijay K. Singh, Stephen Y. Wise, Thomas M. Seed, Patricia L. P. Romaine, Oluseyi O. Fatanmi, and Victoria L. Newman
- Subjects
0301 basic medicine ,Paper ,Male ,Radiation-Protective Agents ,Pharmacology ,Granulocyte ,Radiation Dosage ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Amifostine ,In vivo ,medicine ,Animals ,Vitamin E ,Radiology, Nuclear Medicine and imaging ,Chromans ,gamma-Tocotrienol ,Survival rate ,Radiation ,Radiological and Ultrasound Technology ,Dose-Response Relationship, Drug ,business.industry ,Public Health, Environmental and Occupational Health ,Acute Radiation Syndrome ,Dose-Response Relationship, Radiation ,General Medicine ,Total body irradiation ,Survival Rate ,Dose–response relationship ,Drug Combinations ,Radiation Injuries, Experimental ,030104 developmental biology ,medicine.anatomical_structure ,Treatment Outcome ,chemistry ,030220 oncology & carcinogenesis ,business ,Whole-Body Irradiation ,medicine.drug - Abstract
This study was designed to evaluate the possible potentiation of survival protection afforded by relatively low-dose amifostine prophylaxis against total body irradiation in combination with a protective, less toxic agent, gamma-tocotrienol (GT3). Mice were administered amifostine and/or GT3, then exposed to 9.2 Gy 60Co γ-irradiation and monitored for survival for 30 days. To investigate cytokine stimulation, mice were administered amifostine or GT3; serum samples were collected and analyzed for cytokines. Survival studies show single treatments of GT3 or amifostine significantly improved survival, compared to the vehicle, and combination treatments resulted in significantly higher survival compared to single treatments. In vivo studies with GT3 confirmed prior work indicating GT3 induces granulocyte colony-stimulating factor (G-CSF). This approach, the prophylactic combination of amifostine and GT3, which act through different mechanisms, shows promise and should be investigated further as a potential countermeasure for acute radiation syndrome.
- Published
- 2016
14. Radiofrequency Exposure Amongst Employees of Mobile Network Operators and Broadcasters
- Author
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Martie van Tongeren, Ian Litchfield, and Tom Sorahan
- Subjects
Paper ,Occupational group ,Activities of daily living ,Rf exposure ,Radio Waves ,Broadcasting ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Electromagnetic Fields ,Adverse health effect ,Environmental health ,Journal Article ,Humans ,Industry ,Radiology, Nuclear Medicine and imaging ,Radiation ,Radiological and Ultrasound Technology ,business.industry ,Rf radiation ,Public Health, Environmental and Occupational Health ,General Medicine ,Radiation Exposure ,030210 environmental & occupational health ,Workforce ,Cellular network ,Telecommunications ,Television ,Business - Abstract
Little is known about personal exposure to radiofrequency (RF) fields amongst employees in the telecommunications industry responsible for installing and maintaining transmitters. IARC classified RF exposure as a possible carcinogen, although evidence from occupational studies was judged to be inadequate. Hence, there is a need for improved evidence of any potentially adverse health effects amongst the workforce occupationally exposed to RF radiation. In this study, results are presented from an exposure survey using data from personal monitors used by employees in the broadcasting and telecommunication industries of the UK. These data were supplemented by spot measurements using broadband survey metres and information on daily work activities provided by employee questionnaires. The sets of real-time personal data were categorised by four types of site determined by the highest powered antenna present (high, medium or low power and ground-level sites). For measurements gathered at each type of site, the root mean square and a series of box plots were produced. Results from the daily activities diaries suggested that riggers working for radio and television broadcasters were exposed to much longer periods as compared to colleagues working for mobile operators. Combining the results from the measurements and daily activity diaries clearly demonstrate that exposures were highest for riggers working for broadcasting sites. This study demonstrates that it is feasible to carry out exposure surveys within these populations that will provide reliable estimates of exposure that can be used for epidemiological studies of occupational groups exposed to RF fields.
- Published
- 2016
15. A new large-volume metal reference standard for radioactive waste management
- Author
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P. Kovář, H. Stroh, O. Burda, Z. Tyminski, Mikael Hult, J. Suran, A. Listkowska, F. Tzika, Dirk Arnold, and Gerd Marissens
- Subjects
Materials science ,Silver ,engineering.material ,Metal ,Waste Management ,Centrifugal casting (industrial) ,Radiation Monitoring ,Calibration ,Humans ,Radiology, Nuclear Medicine and imaging ,Neutron ,Cobalt Radioisotopes ,Reference standards ,Radiation ,Radiological and Ultrasound Technology ,Metallurgy ,Public Health, Environmental and Occupational Health ,Radioactive waste ,General Medicine ,Reference Standards ,Volume (thermodynamics) ,visual_art ,Radioactive Waste ,Papers ,visual_art.visual_art_medium ,engineering ,Cast iron - Abstract
A new large-volume metal reference standard has been developed. The intended use is for calibration of free-release radioactivity measurement systems and is made up of cast iron tubes placed inside a box of the size of a Euro-pallet (80 × 120 cm). The tubes contain certified activity concentrations of (60)Co (0.290 ± 0.006 Bq g(-1)) and (110m)Ag (3.05 ± 0.09 Bq g(-1)) (reference date: 30 September 2013). They were produced using centrifugal casting from a smelt into which (60)Co was first added and then one piece of neutron irradiated silver wire was progressively diluted. The iron castings were machined to the desirable dimensions. The final material consists of 12 iron tubes of 20 cm outer diameter, 17.6 cm inner diameter, 40 cm length/height and 245.9 kg total mass. This paper describes the reference standard and the process of determining the reference activity values.
- Published
- 2015
16. VISIBILITY OF STRUCTURES OF RELEVANCE FOR PATIENTS WITH CYSTIC FIBROSIS IN CHEST TOMOSYNTHESIS: INFLUENCE OF ANATOMICAL LOCATION AND OBSERVER EXPERIENCE
- Author
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Åse Allansdotter Johnsson, Susanne Kheddache, Carin Meltzer, Helga Asgeirsdottir, M. Gilljam, and Magnus Båth
- Subjects
Thorax ,Paper ,Adult ,Male ,medicine.medical_specialty ,Observer (quantum physics) ,Adolescent ,Cystic Fibrosis ,Anatomical structures ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,Prospective Studies ,Observer Variation ,Radiation ,Anatomical location ,Radiological and Ultrasound Technology ,business.industry ,Visibility (geometry) ,Public Health, Environmental and Occupational Health ,Reproducibility of Results ,General Medicine ,Middle Aged ,Tomosynthesis ,Diaphragm (structural system) ,Radiographic Image Enhancement ,030220 oncology & carcinogenesis ,Radiographic Image Interpretation, Computer-Assisted ,Female ,Radiography, Thoracic ,Radiology ,business ,Tomography, X-Ray Computed - Abstract
The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in 14 % of the ratings. Central and peripheral lateral structures received higher visibility ratings compared with peripheral structures anteriorly, posteriorly and surrounding the diaphragm (p ≤ 0.001). Reported visibility was significantly higher for the most experienced observer (p ≤ 0.01). The results indicate that minor pathology can be difficult to visualise with DTS depending on location and observer experience. Central and peripheral lateral structures are generally well depicted.
- Published
- 2016
17. EXPOSURE OF THE SWISS POPULATION BY RADIODIAGNOSTICS: 2013 REVIEW
- Author
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Régis Le Coultre, David Wittwer, Philipp R. Trueb, Mélanie Champendal, Abbas Aroua, Julie Bize, Francis R. Verdun, and Nick Ryckx
- Subjects
Paper ,medicine.medical_specialty ,Databases, Factual ,Population ,Computed tomography ,Pilot Projects ,Radiation Dosage ,Radiography, Interventional ,Effective dose (radiation) ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Radiation Monitoring ,Environmental health ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Medical physics ,education ,education.field_of_study ,Radiation ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,X-Rays ,Public Health, Environmental and Occupational Health ,General Medicine ,Environmental exposure ,Environmental Exposure ,Hybrid approach ,Radiography ,Tomography x ray computed ,030220 oncology & carcinogenesis ,Western europe ,Total dose ,business ,Tomography, X-Ray Computed ,Switzerland - Abstract
In 2013, a nationwide investigation was conducted in Switzerland to establish the population's exposure from medical X rays. A hybrid approach was used combining the Raddose database accessible on-line by the participating practices and the Swiss medical tariffication system for hospitals. This study revealed that the average annual number of examinations is 1.2 per inhabitant, and the associated annual effective dose is 1.4 mSv. It also showed that computed tomography is the most irradiating modality and that it delivers 70 % of the total dose. The annual effective dose per inhabitant registered a 17 % increase in 5 y and is comparable with what was recently reported in neighbouring countries.
- Published
- 2016
18. EFFECT OF RADIATION DOSE LEVEL ON ACCURACY AND PRECISION OF MANUAL SIZE MEASUREMENTS IN CHEST TOMOSYNTHESIS EVALUATED USING SIMULATED PULMONARY NODULES
- Author
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Söderman, Christina, Johnsson, Åse Allansdotter, Vikgren, Jenny, Norrlund, Rauni Rossi, Molnar, David, Svalkvist, Angelica, Månsson, Lars Gunnar, and Båth, Magnus
- Subjects
Paper ,Observer Variation ,Humans ,Radiographic Image Interpretation, Computer-Assisted ,Reproducibility of Results ,Solitary Pulmonary Nodule ,Computer Simulation ,Radiography, Thoracic ,Thorax ,Radiation Dosage ,Radiology ,Tomography, X-Ray Computed ,Lung - Abstract
The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis.
- Published
- 2016
19. AN ANALYSIS OF THE POTENTIAL ROLE OF CHEST TOMOSYNTHESIS IN OPTIMISING IMAGING RESOURCES IN THORACIC RADIOLOGY
- Author
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Magnus Båth, Åse Allansdotter Johnsson, Cecilia Petersson, and Jenny Vikgren
- Subjects
Thorax ,Paper ,Adult ,Male ,medicine.medical_specialty ,Adolescent ,Radiography ,Tertiary referral centre ,Chest ct ,Computed tomography ,030218 nuclear medicine & medical imaging ,Tertiary Care Centers ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Child ,Referral and Consultation ,Aged ,Aged, 80 and over ,Radiation ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Public Health, Environmental and Occupational Health ,Follow up studies ,Reproducibility of Results ,General Medicine ,Middle Aged ,Tomosynthesis ,Tomography x ray computed ,030220 oncology & carcinogenesis ,Female ,Radiography, Thoracic ,Radiology ,business ,Nuclear medicine ,Tomography, X-Ray Computed ,Follow-Up Studies - Abstract
The aim of the study was to investigate the potential role of chest tomosynthesis (CTS) at a tertiary referral centre by exploring to what extent CTS could substitute chest radiography (CXR) and computed tomography (CT). The study comprised 1433 CXR, 523 CT and 216 CTS examinations performed 5 years after the introduction of CTS. For each examination, it was decided if CTS would have been appropriate instead of CXR (CXR cases), if CTS could have replaced the performed CT (CT cases) or if CT would have been performed had CTS not been available (CTS cases). It was judged that (a) CTS had been appropriate in 15 % of the CXR examinations, (b) CTS could have replaced additionally 7 % of the CT examinations and (c) CT would have been carried out in 63 % of the performed CTS examinations, had CTS not been available. In conclusion, the potential role for CTS to substitute other modalities during office hours at a tertiary referral centre may be in the order of 20 and 25 % of performed CXR and chest CT, respectively.
- Published
- 2016
20. External dose-rate conversion factors of radionuclides for air submersion, ground surface contamination and water immersion based on the new ICRP dosimetric setting
- Author
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Gyuseong Cho, Siwan Noh, Jai-Ki Lee, Han-Ki Jang, and Song Jae Yoo
- Subjects
Male ,Water Pollutants, Radioactive ,Nuclear engineering ,Monte Carlo method ,Radiation Dosage ,Soil ,Nuclear Reactors ,Radiation Monitoring ,Reference Values ,Beta particle ,Humans ,Radiology, Nuclear Medicine and imaging ,Computer Simulation ,Tissue Distribution ,Skyshine ,Radiometry ,Radioisotopes ,Radionuclide ,Photons ,Radiation ,Radiological and Ultrasound Technology ,business.industry ,Equivalent dose ,Phantoms, Imaging ,Air ,Public Health, Environmental and Occupational Health ,Water ,General Medicine ,Contamination ,Water immersion ,Air Pollutants, Radioactive ,Papers ,Environmental science ,Female ,Nuclear medicine ,business ,Dose rate ,Radioactive Hazard Release ,Monte Carlo Method - Abstract
For the assessment of external doses due to contaminated environment, the dose-rate conversion factors (DCFs) prescribed in Federal Guidance Report 12 (FGR 12) and FGR 13 have been widely used. Recently, there were significant changes in dosimetric models and parameters, which include the use of the Reference Male and Female Phantoms and the revised tissue weighting factors, as well as the updated decay data of radionuclides. In this study, the DCFs for effective and equivalent doses were calculated for three exposure settings: skyshine, groundshine and water immersion. Doses to the Reference Phantoms were calculated by Monte Carlo simulations with the MCNPX 2.7.0 radiation transport code for 26 mono-energy photons between 0.01 and 10 MeV. The transport calculations were performed for the source volume within the cut-off distances practically contributing to the dose rates, which were determined by a simplified calculation model. For small tissues for which the reduction of variances are difficult, the equivalent dose ratios to a larger tissue (with lower statistical errors) nearby were employed to make the calculation efficient. Empirical response functions relating photon energies, and the organ equivalent doses or the effective doses were then derived by the use of cubic-spline fitting of the resulting doses for 26 energy points. The DCFs for all radionuclides considered important were evaluated by combining the photon emission data of the radionuclide and the empirical response functions. Finally, contributions of accompanied beta particles to the skin equivalent doses and the effective doses were calculated separately and added to the DCFs. For radionuclides considered in this study, the new DCFs for the three exposure settings were within ±10 % when compared with DCFs in FGR 13.
- Published
- 2013
21. 210Po in the dietat Seville (Spain) and its contribution to the dose by ingestion
- Author
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Rafael García-Tenorio, Juan Mantero, J. Díaz-Ruiz, Guillermo Manjón, Inmaculada Díaz-Francés, and Consejo de Seguridad Nuclear (España)
- Subjects
Polonium ,Radioisotopes ,Radionuclide ,education.field_of_study ,Radiation ,Radiological and Ultrasound Technology ,Population ,Public Health, Environmental and Occupational Health ,General Medicine ,Biology ,Radiation Dosage ,Diet ,Eating ,Diet habits ,Animal science ,Radiation Monitoring ,Spain ,Papers ,Body Burden ,Humans ,Ingestion ,Radiology, Nuclear Medicine and imaging ,Composition (visual arts) ,education ,Food Contamination, Radioactive - Abstract
The activity concentrations of 210Po have been determined in a total of 24 representative diet samples from Seville (south of Spain), inferring from the obtained values the annual intakes of 210Po by ingestion of the affected population and the corresponding committed effective doses. The annual intakes of Po and, consequently, the corresponding doses of this radionuclide show a high variability in correspondence with the variability in the composition of the analysed samples over time, and their magnitude is comparable with the estimated ones in other regions/countries of the world with similar diet habits (countries where the marine products have a considerable weight in the diets). Committed effective doses by ingestion higher than 0.1 mSv y have been estimated exclusively for 210Po, reflecting the importance of this radionuclide and this route of incorporation in the magnitude of the total doses received by the affected population from natural sources., This work is an extra deliverable on the frame of an Environmental Radioactivity Surveillance programme carried out since the 1990s by the authors’ research group under the umbrella and financial support of the Spanish Nuclear Security Council.
- Published
- 2016
22. Imaging uranium distribution on rat kidney sections through detection of alpha tracks using CR-39 plastic nuclear track detector
- Author
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Konishi, Teruaki, Kodaira, Satoshi, Itakura, Yuichi, Ohsawa, Daisuke, Shino, Homma-Takeda, Teruaki, Konishi, Satoshi, Kodaira, Yuichi, Itakura, Daisuke, Ohsawa, and Shino, Takeda
- Subjects
technology, industry, and agriculture - Abstract
Uranium is renowned as a global contaminant, and attracts major concern with regards to the health risks involved because its nephrotoxicity. This paper discusses the development of a simple method to identify accumulated regions or localized sites of uranium within kidneys using the CR-39 plastic nuclear track detector. To demonstrate the proposed method, renal cryo-sections (5 μm-t) from Wistar male rats, subcutaneously administered with uranyl acetate (2 mg/kg), were prepared on day one after administration. Concerned sections were subsequently placed on CR-39, stored for 1.25 years, and then etched in a 7 M NaOH solution at 70 ℃ for 3 h. α-tracks were then detected in the form of etch pits, corresponding to uranium, and also the tissue shape and structure were transferred as a roughness on the surface of CR-39. As observed, the proposed method served to facilitate simultaneous detection and identification of localized regions of uranium accumulation within kidneys.
- Published
- 2018
23. Assessment of safety culture in radiotherapy facilities using safety performance indicators.
- Author
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Sharma S, Sivaramakrishnan M, Tripathi A, Dixit PK, Krishnakumar N, Sahani G, Dash Sharma PK, and Sharma SD
- Abstract
This paper describes the development of the Safety Performance Indicators (SPIs), the methodology for assessment of the safety culture of radiotherapy institutions using SPIs and common strengths and common areas for improvement. SPIs were categorized into eight sections which all together contain 23 attributes and each attribute has scoring criteria from 0 to 2 (in steps of 0.5). The maximum absolute cumulative score of SPIs was 46. A relative cumulative SPIs score of >80% indicates an institution strong commitment towards safety while score <50% indicates need for additional guidance to enhance safety culture. The assessment using SPIs was conducted for 17 radiotherapy institutions. The methodology of assessment includes interactive discussion, direct observations and document analysis. The relative cumulative SPIs score of seven institutions was found to be >80% while it was found in the range of 67.0% to 80% for the remaining ten institutions. Institutions were communicated about the cumulative SPIs score, areas of strengths, and areas for improvement. SPIs were found to be a good tool for safety culture assessment and can be utilized by the radiotherapy institutes for self-assessment to identify the areas of improvement. Based on SPIs score, regulatory body can grade the institutions from a radiation safety compliance point of view., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
24. Methodology for shielding design and evaluation for container scanners.
- Author
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Singh TD, Sha RL, Singh RK, Sahani G, Tandon P, and Sharma PKD
- Subjects
- Humans, Radiation Dosage, Photons, X-Rays, Radiation Protection instrumentation, Radiation Protection standards, Equipment Design
- Abstract
There has been an increase in the use of high energy photon beam for container scanners in many countries for multi purposes such as detecting high atomic number materials which might be nuclear materials, drugs, high explosive materials and other contrabands etc. High energy photon beams generally 6 and 9 MV can be used for scanning such materials. However, it is important to ensure that radiation level beyond the container scanner installation is within the permissible dose limit specified by the national competent authority for the protection of public and radiation workers. In this paper, challenges in the biological shielding during the installation of high energy X-ray system for scanning vehicles containing suspected materials are discussed. The purpose of the present study is to develop a methodology for shielding design and evaluation for container scanner installations. The basic concept pertaining to shielding evaluation of radiotherapy installations provided in National Council on Radiation Protection and Measurements (NCRP)/International Atomic Energy Agency (IAEA) reports are referred, and appropriately used to calculate optimized shielding thicknesses requirements for container scanner installation. Workload is estimated based on number of containers scanned, machine ON time and dose rate at 1 m. The shielding evaluation includes use of beam stopper in the primary beam, scattering by heterogeneous metallic scrap materials or any other suspected materials contained in the vehicle and their impact on the thickness of shielding walls. A model lay out plan to be used for installation of container scanner is developed. A methodology for shielding evaluation for various protective walls and ceiling of this model is also discussed. The study provides basic requirement for designing a structural room for installing 9MV container scanner from radiological safety view point., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
25. Radiation dose due to uranium in groundwater to the population of Chamarajanagar district, Karnataka, India.
- Author
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Lavanya BSK, Namitha SN, Manilal S, Ghosh M, and Chandrashekara MS
- Subjects
- India, Humans, Uranium analysis, Groundwater analysis, Water Pollutants, Radioactive analysis, Radiation Monitoring methods, Radiation Dosage
- Abstract
This paper presents the concentration of uranium in 67 groundwater samples of Chamarajanagar district, Karnataka, India, estimated using an LED fluorimeter. The age-dependent ingestion dose to the population of the district is also studied. The concentration of uranium in groundwater varied from 0.20 to 57.50 μg L-1 with an average of 4.40 μg L-1. The annual ingestion dose due to uranium varies from 0.18 to 142.68 μSv y-1, with an average of 7.11 μSv y-1. The ingestion dose received by the population in the study area is less than the recommended level of 100 μSv y-1 by the World Health Organization (2011)., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
26. Role of independent research at AERB for ensuring safety of nuclear facilities in India.
- Author
-
Mohapatra D
- Subjects
- India, Humans, Nuclear Energy, Nuclear Power Plants, Radiation Monitoring methods, Safety Management, Research, Occupational Exposure prevention & control, Occupational Exposure analysis, Radiation, Ionizing, Nuclear Reactors, Radiation Protection standards
- Abstract
The mission of Atomic Energy Regulatory Board (AERB) of India is to ensure that the use of ionising radiation and nuclear energy in India does not cause unacceptable impact on the workers, members of the public and to the environment. AERB has the mandate to carry out detailed safety review for the siting, construction, commissioning, operation and decommissioning of nuclear and radiation facilities established within the country. To deliver and maintain a strong, credible and technically sound regulation, AERB has established the Safety Research Institute (SRI) at Kalpakkam with a robust technical infrastructure and wide knowledge base. This paper highlights the independent safety research activities carried out at SRI and its role to support and facilitate the decision-making process by AERB at various stages of regulatory review for ensuring safety of the nuclear facilities in India., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
27. Technologies for retrospective radiation dosimetry.
- Author
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Narayan P
- Subjects
- Humans, Retrospective Studies, Radiometry methods, Gamma Rays, Electron Spin Resonance Spectroscopy methods, Radiation, Ionizing, Radiation Dosage, Radiation Monitoring methods, Thermoluminescent Dosimetry methods, Thermoluminescent Dosimetry instrumentation
- Abstract
Radiation dosimetry is an important task for assessing the biological damages created in human being due to ionising radiation exposure. Ionising radiation being invisible and beyond the perception of human natural sensors, the dosimetry equipments/systems are the utmost requirement for its measurement. Retrospective measurement of radiation doses is a challenging task as conventional radiation dosemeters are not available at the exposure site. The material/s in close proximity of exposed individual or individuals' biological samples may be used as retrospective radiation sensor for dosimetry purpose. Environment materials such as sand, bricks, ceramics, sand stones, quartz, feldspar, glasses and electronic chips have been utilised using TL (Thermoluminescence) techniques for retrospective gamma dose (min 10 cGy) measurement. Electron Spin Resonance techniques have been employed to human biological samples such as tooth enamel, bones, nails, hair, etc. and reported for dosimetry for ~20 cGy min dose measurement. Some commercial glasses have been found sensitive enough to measure the minimum gamma doses of the order of 100 cGy using TL techniques. For internal retrospective dosimetry, the radioactivity contamination assessment in food items, water, other edible product and ambient air are the prerequisites. The radioactivity concentration vis-à-vis their consumption rate may help in controlling the internal contamination and estimation of dose absorption in human body. Defence Laboratory, Jodhpur has been working extensively on the dosimetry techniques for external dose measurement using environmental material and developed portable contamination monitoring systems for food and water radioactivity measurement in the range of 50 Bq kg-1 to 1000 kBq kg-1 in 60 s measurement time. The recent research and development in the methodologies, equipments and systems undertaken towards capacity building and self-reliance in retrospective radiation dosimetry is reported in this paper., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
28. Long-term monitoring of outdoor natural gamma absorbed dose rate in air in Bengaluru, Karnataka, India.
- Author
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Mitra P, Srivastava S, Reddy GP, Garg S, and Kumar AV
- Subjects
- India, Humans, Radiation Monitoring methods, Gamma Rays, Air Pollutants, Radioactive analysis, Radiation Dosage, Background Radiation
- Abstract
This research forms a part of the comprehensive Indian Environmental Radiation Monitoring Network program, focusing on the continuous measurement of absorbed dose rate in outdoor air due to natural gamma radiation (cosmic and terrestrial) in Bengaluru, Karnataka, India. Over the course of a decade (2013-2023), data were collected from 41 monitoring locations in the city using permanently field-installed Geiger-Mueller detector-based environmental radiation monitors. This paper presents an analysis of the extensive long-term monitoring results. The mean absorbed gamma dose rate in outdoor air across the monitoring locations ranged from 84 ± 9 to 156 ± 4 nGy.h-1, with a calculated mean value of 124 ± 15 nGy.h-1. The estimated mean annual effective dose due to outdoor natural gamma radiation varied from 0.10 ± 0.01 to 0.19 ± 0.01 mSv.y-1, with an overall mean of 0.15 ± 0.02 mSv.y-1., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
29. Evaluation of uncertainty in personal dose measured using CaSO4:Dy-based TLD badge at different workplaces.
- Author
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Pradhan SM, Pathan MS, Chakrabarty S, Selvam TP, and Sapra BK
- Subjects
- Humans, Uncertainty, Radiation Monitoring methods, Algorithms, Dysprosium chemistry, Photons, Radiation Protection methods, Radiation Protection standards, Radiation Dosimeters, Thermoluminescent Dosimetry instrumentation, Thermoluminescent Dosimetry methods, Occupational Exposure analysis, Radiation Dosage, Workplace
- Abstract
The metrological quality of a measurement is characterised by evaluating the uncertainty in the measurement. In this paper, uncertainty in personal dose measured using individual monitoring CaSO4:Dy-based thermoluminescence dosimeter badge is evaluated by application of the guide to the expression of uncertainty in measurement method. The present dose reporting quantity, whole body dose (WBD) and the proposed quantity, personal dose equivalent, Hp(10) has been used as measurands. The influence of various input quantities on the measurement were analyzed through tests that conform to the requirements of the International Electrotechnical Commission IEC 62387. The study found that the expanded uncertainties for WBD and Hp(10) measurements were 63.4% and 41.4%, respectively, corresponding to a 95% coverage probability for workplace fields covering a wide photon energy range (33-1250 keV). However, the uncertainty estimates were quite lower for the type of workplaces that are identified using the dose evaluation algorithm. The input quantities, namely, the response to a mixture of photon beam qualities and photon energy and angular dependence contribute the most to the total uncertainty., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
30. The exposure analysis of the long-term broadband EMF monitoring in the campus area of the University of Novi Sad.
- Author
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Kljajic D, Djuric N, Skoric T, and Djuric S
- Subjects
- Humans, Universities, Serbia, Pandemics, Environmental Exposure analysis, Electromagnetic Fields, COVID-19 epidemiology, COVID-19 transmission, Radiation Monitoring methods, SARS-CoV-2
- Abstract
Due to wide prevalence of electromagnetic field (EMF) sources in human surrounding, EMF-level measurements and corresponding exposure assessment have imposed as an important topic. With an intention to present an approach to the long-term exposure assessment in EMF RATEL network, this paper conveys a high-level statistical analysis of the high-frequency exposure data, acquired during the 5-y time period, for the case study of monitoring sensor installed in the area of the Novi Sad University campus. Time series of exposure values were averaged on a daily, weekly, and monthly basis, and their yearly comparison was performed. Results showed clear differences between the day and night hours, as well between working and weekend days. Regarding exposure values, averaged on the monthly basis, the impact of COVID-19 pandemic in 2020 and 2021 can be noticed. Finally, the highest obtained exposure values (electric field squared) were 22 times below the maximal allowable level, according to the Serbian legislation., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
31. Estimation of 241Am and 239Pu activity embedded in the tissue using portable planar HPGe detector.
- Author
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Murugan M, Ponraj S, Ramasamy M, Durairaj P, and Balasubramanian V
- Subjects
- Humans, Radiation Monitoring methods, Radiation Monitoring instrumentation, Radiation Dosage, Radiometry methods, Radiometry instrumentation, Plutonium analysis, Americium analysis, Germanium analysis
- Abstract
This paper describes a procedure for the estimation of 241Am and 239Pu activity present in the human tissue by measuring the depth of contaminant using a portable Planar High Purity Germanium detector (HPGe). The ratios of photopeak counts of X-rays or gammas obtained with the detector coupled to collimator are calculated for the estimation of depth of the contaminant and the optimum one is determined. Since Minimum Detectable Activities (MDA) for the detector coupled to a collimator are higher than that of bare detector, activity must be estimated using bare detector, after locating the contaminant. Two methods are described for the estimation of plutonium coexisting with 241Am: (i) Abundance and isotopic correction for 239Pu (ii) and 239Pu:241Am ratio. The procedure to estimate 239Pu when plutonium isotopes alone are present is also established. An optimum monitoring period to detect the minimum value of intake for both radionuclides corresponding to chelation therapy and excision is also derived., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
32. Medical staff monitoring in interventional cardiology: over apron dosemeter placement based on measurements and simulations.
- Author
-
Ferrari P, Venturi G, Campani L, Mariotti F, Becker F, Jansen J, Jovanović Z, Krstić D, and Teles P
- Subjects
- Humans, Cardiology methods, Medical Staff, Thorax radiation effects, Occupational Exposure analysis, Occupational Exposure prevention & control, Radiation Protection methods, Monte Carlo Method, Phantoms, Imaging, Radiation Dosage, Computer Simulation, Radiation Monitoring methods, Protective Clothing
- Abstract
Interventional cardiology is characterized by high radiation exposure for both the patient and the operator. Adequate shielding and monitoring of the operator are fundamental to comply with radiation protection principles. In a previous work, the effect on the dose of the dosemeter position on the chest was studied. In this paper, the investigation has been completed, employing an anthropomorphic thorax phantom, equipped with arms. Although there are differences between the Monte Carlo simulations and the measurements, similar trends are observed, showing that the reduction in dose, due to the arms, is between 20 and 60%, compared with the situation without arms. For that reason, considering a dosemeter placed on the chest, the upper position, which is the least affected by the arms, should be preferred while the extreme lateral position, near the armpit, should be avoided., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
33. Size specific dose estimation in pediatric CT: preliminary study and conversion factors.
- Author
-
Zhang J and Zhang X
- Subjects
- Humans, Child, Child, Preschool, Adolescent, Infant, Female, Male, Retrospective Studies, Infant, Newborn, Head diagnostic imaging, Head radiation effects, Radiography, Thoracic methods, Tomography, X-Ray Computed methods, Radiation Dosage
- Abstract
The objective of this paper is to compare the differences between volumetric CT dose index (CTDIVOL) and size-specific dose estimate (SSDEWED) based on water equivalent diameter (WED) in radiation dose measurement, and explore a new method for fast calculation of SSDEWED. The imaging data of 1238 cases of head, 1152 cases of chest and 976 cases of abdominopelvic were analyzed retrospectively, and they were divided into five age groups: ≤ 0.5, 0.5 ~ ≤ 1, 1 ~ ≤ 5, 5 ~ ≤ 10 and 10 ~ ≤ 15 years according to age. The area of interest (AR), CT value (CTR), lateral diameter (LAT) and anteroposterior diameter (AP) of the median cross-sectional image of the standard scanning range and the SSDEWED were manually calculated, and a t-test was used to compare the differences between CTDIVOL and SSDEWED in different age groups. Pearson analyzed the correlations between DE and age, DE and WED, f and age, and counted the means of conversion factors in each age group, and analyze the error ratios between SSDE calculated based on the mean age group conversion factors and actual measured SSDE. The CTDIVOL in head was (9.41 ± 1.42) mGy and the SSDEWED was (8.25 ± 0.70) mGy: the difference was statistically significant (t = 55.04, P < 0.001); the CTDIVOL of chest was (2.68 ± 0.91) mGy and the SSDEWED was (5.16 ± 1.16) mGy, with a statistically significant difference (t = -218.78, P < 0.001); the CTDIVOL of abdominopelvic was (3.09 ± 1.58) mGy and the SSDEWED was (5.89 ± 2.19) mGy: the difference was also statistically significant (t = -112.28, P < 0.001). The CTDIVOL was larger than the SSDEWED in the head except for the ≤ 0.5 year subgroup, and CTDIVOL was smaller than SSDEWED within each subgroup in chest and abdominopelvic. There were strong negative correlations between f and age (head: r = -0.81; chest: r = -0.89; abdominopelvic: r = -0.86; P < 0.001). The mean values of f at each examination region were 0.81 ~ 1.01 for head, 1.65 ~ 2.34 for chest and 1.71 ~ 2.35 for abdominopelvic region. The SSDEWED could be accurately estimated using the mean f of each age subgroup. SSDEWED can more accurately measure the radiation dose of children. For children of different ages and examination regions, the SSDEWED conversion factors based on age subgroup can be quickly adjusted and improve the accuracy of radiation dose estimation., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
34. A fast correction method of the scattering contributions in the area gamma dosemeter calibration field.
- Author
-
Qian YK, Zhang S, Mao BJ, and Liu YX
- Subjects
- Calibration, Computer Simulation, Gamma Rays, Monte Carlo Method, Radiation Dosage, Radiation Dosimeters
- Abstract
In the calibration procedure of area gamma dosemeters, how to accurately evaluate and correct the scattering contribution from the complex environmental factors to the point of test is the key problem to ensure the calibration accuracy. This paper proposed a fast correction method of the scattering contributions in the area gamma dosemeter calibration field. First, Monte Carlo method is employed to simulate the influence of scattering caused by different environmental factors in the calibration field, which is named as semi-panoramic reference radiation field. Then, a prediction model of the relationship between environmental factors and environmental scattering contribution is constructed based on the simulation data through the least squares support vector machine. With the model, the scattering contribution from the environmental factors can be fast estimated to correct the calibration results of the area gamma dosemeters, which will improve the accuracy of the calibration., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
35. A preliminary study on determination of radioactivity levels and estimation of the annual effective dose in dried fruits consumed in Albania.
- Author
-
Spahiu E, Shyti M, and Bërdufi I
- Subjects
- Humans, Fruit chemistry, Cesium Radioisotopes analysis, Potassium Radioisotopes analysis, Thorium analysis, Albania, Radioactivity, Radium analysis, Soil Pollutants, Radioactive analysis, Radiation Monitoring
- Abstract
This work aimed to support Albania's food safety monitoring regime. In this context, the natural and artificial radioactivity was measured in 20 samples of dried fruits collected randomly in different markets of Tirana. The activity concentration of 40K, 226Ra, 232Th and 137Cs was determined by using the high-purity germanium detector. The maximum values of activity concentration in dried fruits were calculated as 517 ± 22 Bq kg-1 for 40K, 11.10 ± 0.93 Bq kg-1 for 226Ra, 4.38 ± 0.26 Bq kg-1 for 232Th and 0.83 ± 0.14 Bq kg-1 for 137Cs. The average values of activity concentration of 40K and 226Ra were 269and 6.05 Bq kg-1 and the average effective dose to individuals from the intake of the dried fruits was 44 μSv y-1. All average values in this study were lower than recommended values by reports United Nations Scientific Committee on the Effect of Atomic Radiation, World Health Organization and International Commission on Radiological Protection for all age groups. Therefore, all dried fruit samples in this study are safe for consumption with acceptable radiological risk and none of them pose any significant radiological impact. The obtained data in this paper and information for levels of radioactivity and ingestion absorbed dose from dried fruits can be used to be the basic data for future comparative analysis of the other studies., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
36. Metrology supporting the European regulation for radiation protection.
- Author
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Alves JG, Caldeira MC, Röttger A, Khanbabaee B, Adam-Guillermin C, Siiskonen T, Živanović M, Šabeta A, and Glavič-Cindro D
- Subjects
- European Union, Industry, Radiation, Ionizing, Radiation Protection
- Abstract
The European Association of National Metrology Institutes (EURAMET) within its research programme European Metrology Programme for Innovation and Research (EMPIR) funded project EMPIR 19NET03 supportBSS that contributes to the establishment of a European Metrology Network (EMN) for Radiation Protection (RP). The EMN-RP was established in September 2021 with the intent to work as a meeting point for the metrology community and all stakeholders in the field of ionising radiation regulation, thus providing quality assurance for measurements in each of the exposure situations contemplated in the European Legislation. Within project EMPIR 19NET03, work package 3 aims at the preparation of a Strategic Research Agenda (SRA) by identifying the metrology needs to support the European legislation and regulation in Radiation Protection and of two Roadmaps for metrology services, one under the European Council Directive 2013/59/EURATOM and the other under the EURATOM Treaty. Following a Gaps Workshop held in September 2020 and a second internal workshop that took place in April 2022, a questionnaire was prepared for distribution to the stakeholders, e.g. RP platforms and authorities, academia, industry, among other, together with an accompanying paper. In this paper, the authors present the state of the art of European legislation in RP, address the importance of metrology, the practices and activities that need metrology to meet the requirements set in the regulations, emphasise the need for quality assured measurements in all fields, highlight the stakeholders contributions in their specific area and show their vision of the EMN-RP., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
37. A new proposed procedure for calibrating personal dosemeters for X and gamma radiations, based on Hp(30)water.
- Author
-
Bouzegzi K, Amroun-Frahi A, Medjadj T, and Herrati A
- Subjects
- Radiation Dosage, Gamma Rays, Photons, Cesium Radioisotopes, Radiation Protection methods
- Abstract
Recently, a new operational quantity Hp(30)water has been proposed to replace Hp(10). This paper describes a new proposed procedure for calibrating personal dosemeters, for X and gamma radiations, in terms of this new quantity Hp(30)water. Compared to the current procedure based on Hp(10), the proposed procedure requires fewer steps and it is easier to implement. Indeed, this new procedure is based on the direct measurement of the quantity of interest, unlike the current one that necessitates the measurement of an intermediate quantity, the air kerma and then the use of conversion coefficients. Some of the advantages of the proposed procedure, such as no need of conversion coefficients to determine the value of the quantity of interest, and no need of additional material to ensure the conditions of electronic equilibrium of the secondary electrons, are highlighted. The feasibility of the proposed procedure is verified. The fluence-to-Hp(30)water conversion coefficients are measured for Cs-137 and Co-60 radiation qualities, and are found in good agreement with those available in the literature., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2024
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- View/download PDF
38. Study on the safety assessment and protection design of human exposure to low-frequency magnetic fields in electric vehicles.
- Author
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Tan L, Li G, Xie Q, Xiang Y, and Luo B
- Subjects
- Humans, Magnetic Fields, Electromagnetic Fields adverse effects
- Abstract
As the power performance of electric vehicles continues to improve, the human body may be exposed to electromagnetic threats in the cabin. This study tested an electric vehicle to analyze the low-frequency magnetic field distribution in the cabin and to assess the safety of human low-frequency magnetic field exposure. A simulation analysis of human electromagnetic exposure was carried out to obtain the magnetic flux density, induced electric field strength and induced current density, and the test results were much lower than the limits specified in GB8702-2014 and the International Commission on Non-Ionizing Radiation Protection, and the relative error between the simulation results and the test results was <15%. This paper investigates the frequency, driving current, vehicle body material and cable layout to explore the law of human body induced electromagnetic field changing with power cable current, and provides theoretical reference for the design of human body low-frequency magnetic field protection., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
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39. Monitoring of outdoor natural gamma absorbed dose rate in air in Hyderabad, Telangana, India.
- Author
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Mitra P, Reddy GP, Srivastava S, Salunkhe SS, Kumari A, Gavas SG, Ninawe PR, Thekkinkattil M, Garg S, and Kumar AV
- Subjects
- Gamma Rays, Radioisotopes, India, Background Radiation, Radiation Dosage, Soil Pollutants, Radioactive analysis, Radiation Monitoring
- Abstract
The Indian Environmental Radiation Monitoring Network continuously monitors the outdoor natural gamma absorbed dose rate in air at different locations throughout India by employing Geiger-Mueller (GM) detector-based field-installed environmental radiation monitors (ERMs). Hyderabad, Telangana, India is known to have high natural background radiation levels due to the presence of high concentrations of primordial radionuclides in its granitic rocks. There are a total of 59 ERMs installed at various locations across Hyderabad. Long-term monitoring data of these locations are presented in this paper. The mean values of outdoor natural gamma absorbed dose rate in air at the monitoring locations were found to vary in the range of 104-258 nGy.h-1 with a mean of 193 ± 40 nGy.h-1. The mean annual effective dose due to outdoor natural gamma radiation was estimated to be 0.24 ± 0.05 mSv.y-1. Analysis of the long-term seasonal variation of outdoor natural gamma absorbed dose rate in air showed that the same was lowest during monsoons., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
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40. A silicon photomultiplier based compact gamma spectrometer for environmental gamma radiation monitoring networks.
- Author
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Srivastava S, Mitra P, Kumar A, Tyagi M, Kumar AV, and Topkar A
- Subjects
- Gamma Rays, Computer Simulation, Cesium Radioisotopes, Radiation Monitoring
- Abstract
In this paper, the details of the development and performance characterisation of a compact, low-power gamma spectrometer for environmental gamma radiation monitoring networks are presented. To reduce the power consumption and the size of the spectrometer, a gamma detector comprising a silicon photomultiplier coupled to a Gd3Ga3Al2O12:Ce,B (GGAG:Ce,B) scintillator has been used for gamma spectrometry. Initially, a Monte Carlo simulation study was carried out to verify the suitability of the 5 mm × 5 mm × 5 mm GGAG:Ce,B crystal for spectrometry of gamma sources in the energy range 60-1332 keV. For minimising the power consumption, the signal processing electronics has been custom designed. This electronics was realised using standard off-the-shelf components to reduce the cost. The developed spectrometer is of size 16 cm × 10 cm × 6 cm, weighs 600 g and consumes 600 mW power. The spectrometer is developed such that it could be directly interfaced with GSM/Xbee for wireless communication with the radiation monitoring networks. The lower-level discriminator threshold of the system is 40 keV and the total electronic noise is <20 keV. The experimentally measured sensitivity of the spectrometer for 137Cs (662 keV) is 2.4 cps/μGy/h at 3.5 V overvoltage. The spectrometer offers excellent linearity over the measured energy range of 60-1332 keV and an energy resolution of ~10% for 662 keV gamma-ray at room temperature., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
41. Practical overview of the ICRP Publication 145 phantoms for use with MCNP.
- Author
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Hetrick L, Douglas J, and Poudel D
- Subjects
- Monte Carlo Method, Neutrons, Phantoms, Imaging, Radiation Dosage, Photons, Radiometry
- Abstract
This paper provides a practical overview of the mesh-type reference phantoms (MRCPs) published by the ICRP by providing supplementary guidance on the proper implementation of using the MRCPs in computational codes, such as Monte Carlo N-Particle. Various validation scenarios for photon and neutron exposures were also examined where published values were reproduced using the MRCPs for both external and internal exposures. Generally, the MRCPs performed well in the validation scenarios with the values reproduced being within 10% of the published values., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
42. Assessment of radioactivity levels and radiological hazard indices in phosphate and phosphate mine waste samples from Algeria.
- Author
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Djabou RE and Belafrites A
- Subjects
- Thorium analysis, Phosphates analysis, Algeria, Potassium Radioisotopes analysis, Radium analysis, Uranium analysis, Radioactivity, Radiation Monitoring methods
- Abstract
Phosphate ore is the starting raw material for production of all phosphate products including fertilisers phosphate waste. It can be of sedimentary, volcanic or biological origin. Like any other geological material found in nature, it contains various amounts of naturally occurring primordial radionuclides, such as 238U series, 232Th series and 40K. Gamma-ray spectrometry was used to assess natural radioactivity levels and radiological hazard indices in phosphate samples. In this paper, the specific activity concentrations of 226Ra, 232Th and 40K of phosphate ores, merchant and mine waste samples were determined. Based on the activity concentrations, the radiation hazard indices (Raeq, Hex, Hin and I𝛾𝑟), and the radiation doses (D, AED and ELCR) were calculated. The results were discussed and compared with those from other studies as well as recommended safety limit values., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
43. Radiation exposure in interventional cardiology: extremities doses.
- Author
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El Hassane C, Ali AB, Bendaoud N, and Boushaki GMI
- Subjects
- Humans, Radiation Dosage, Radiology, Interventional methods, Extremities, Cardiology methods, Lens, Crystalline, Radiation Exposure analysis, Occupational Exposure analysis
- Abstract
X-rays are widely used in interventional cardiology (IC). Medical staff is exposed to ionising radiations with difficulties to accurately estimate the absorbed dose, on the other hand, it is well known that eye lens and extremities are the most exposed. In most IC units, radiological monitoring is performed by measuring the personal dose equivalent with a dosemeter worn under the operator's apron. The ambient dose equivalent is, usually, also measured. Furthermore, doses to the lens and extremities are often not measured because of the absence or difficulty of wearing the appropriate dosemeters. The main aim of our study is to estimate the extremities doses, of the interventional cardiologists, from the personal dose equivalent, the patient's received doses or to the ambient dose equivalent. For this purpose, we use a radiological monitoring, of four (04) interventional cardiologists, carried out at Algiers hospital. A Monte Carlo calculation is performed for comparison. This paper reports the preliminary results of this study., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
44. Estimation of radiation dose due to thoron and progeny inhalation in high background natural radiation area of Odisha, India.
- Author
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Ramola RC, Prasad M, Sahoo SK, and Tokonami S
- Subjects
- Background Radiation, Radon Daughters analysis, Housing, India, Radiation Dosage, Air Pollutants, Radioactive analysis, Air Pollution, Indoor analysis, Radiation Monitoring methods, Radon analysis
- Abstract
Results of the preliminary measurements of indoor radon, thoron and progeny concentrations showed very high values of thoron concentrations in the eastern coastal region of Odisha, India. Therefore, measurements of thoron and its progeny concentrations were extended to a larger number of houses in this area for the assessment of the radiation dose received by the public. The measured values of thoron concentrations were used for the calculation of annual effective doses. The estimated values of the annual effective dose due to thoron exposure were observed in the range of 0.2-14.7 mSv. The estimated radiation doses responsible for thoron exposure were observed considerably high in the region. The results obtained are compared with those obtained in other studies performed so far in the study area and a review of different studies involving different measurement techniques is presented in the paper. The results of this study support the preliminary studies showing high values of thoron levels in the study area., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
45. Experiences in transitioning a testing laboratoryto the new ISO/IEC 17025:2017 standard.
- Author
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Hajek M, Bavio MA, Benesch TN, Suárez RC, Hamel N, Pinak M, Tucker DM, and Wilding A
- Subjects
- Reference Standards, Laboratories, Accreditation
- Abstract
Since its inception, the international quality standard ISO/IEC 17025 has been revised twice. The most recent edition adopted a new structure to align with other conformity assessment and quality management standards, harmonized the terminology with the International Vocabulary of Metrology and introduced the concept of risk-based thinking. This paper disseminates the experience of the IAEA Radiation Safety Technical Services Laboratory in successful transition and re-accreditation to ISO/IEC 17025:2017. It covers all stages of the transition cycle: from conducting a gap analysis between the existing quality system and the requirements in the revised standard, updating the corresponding quality documents, developing training and communication plans for laboratory personnel, to monitoring the changes and improving the system through auditing, management review and participation in proficiency testing schemes. Lessons learned about building operational resilience and maintaining a business continuity management system to prepare for, respond to, and recover from disruptions are considered., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
46. Numerical model of human head phantom to ensure dosimetry of dose components for boron neutron capture therapy.
- Author
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Michaś E, Tyminska K, Gryzinski MA, Kocik J, and Barczynski RJ
- Subjects
- Humans, Radiometry methods, Neutrons, Radiotherapy Dosage, Phantoms, Imaging, Boron Neutron Capture Therapy methods
- Abstract
Extremely important aspects of the boron neutron capture therapy are, first of all, administering to the patient a boron compound that selectively reaches the neoplastic cells, and in the second step, the verification of the irradiation process. This paper focuses on the latter aspect, which is the detailed dosimetry of the processes occurring after the reaction of thermal neutrons with the boron-10 isotope. The results of computer simulations with the use of a new type of human head phantom filled with a polymer dosimetric gel will be presented in this article., (© The Author(s) 2023. Published by Oxford University Press.)
- Published
- 2023
- Full Text
- View/download PDF
47. Optimization of calibration interval based on equipment metrological history.
- Author
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Moreno B
- Subjects
- Calibration, Uncertainty, Technology, Radiometry methods, Radiation Dosimeters
- Abstract
The purpose of this paper is to describe a method for optimizing the calibration period of a dosimetry measurement system with a focus on the personal dose equivalents Hp(d) and individual monitoring services. The systematic and analytical method developed provides a justification to the calibration interval based on experimental data and measurement uncertainties. Its main input is the metrological history of the equipment that is then used to predict the drift of the measurement system. The method is used to make the calibration operation more efficient over time in terms of cost and metrology. After a description of the method itself, the example of the OSL dosemeter reading process will be discussed and results will be shown. The method developed may be applied to other measurement processes no matter the technology used., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
48. EURADOS intercomparisons on whole-body dosemeters for photons from 2008 to 2020: analysis and comparison of general results.
- Author
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Stadtmann H, Figel M, Grimbergen T, McWhan A, and Romero AM
- Subjects
- Humans, Radiation Dosage, Reproducibility of Results, Radiometry methods, Photons, Radiation Monitoring methods, Radiation Protection methods
- Abstract
Starting in 2008 the European Dosimetry Group (EURADOS) has been performing international intercomparisons (ICs) on photon whole-body dosemeters for individual monitoring services. These ICs have been organized (on a biennial basis) starting 2008 up to 2020 now, each time with a similar set-up but with small alterations in the subsequent irradiation plans. The response for Hp(10) and Hp(0.07) was tested for different radiation qualities, angles of incidences (0°-60°) within a wide range of dose values (0.5-500 mSv), to check energy and angular response, linearity, reproducibility and mixed-field response. Within the last 12 years almost 15 000 whole body dosemeters have been irradiated and the corresponding response values evaluated. With an increasing number of participants and participating systems (from 62 to 132), this IC program has become an important tool for individual monitoring services to test their whole-body dosimetry systems, compare their results with other services or systems and to improve the quality of their dosimetry. The paper presents and compares the general results of these seven ICs and analyses the dosimetric results for the participating system types., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
49. Assessment of the impact on a PADC neutron dosimetry system of the new operational dose quantities proposed in ICRU report 95.
- Author
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Moreno B, Million M, Thomas D, and Taylor G
- Subjects
- Humans, Neutrons, Radiation Dosage, Radiation Monitoring, Radiometry, Occupational Exposure analysis
- Abstract
The International Commission on Radiation Units and Measurements, ICRU, have recommended, in ICRU Report 95, the adoption of new operational quantities for use in radiation protection monitoring. Their implementation will pose problems for instrument manufacturers supplying area dosemeters and for individual monitoring services providing personal dosemeters for radiation workers. The problems arise for photon, neutron and beta dosimetry, but this paper deals solely with neutron personal dosemeters based on poly-allyl diglycol carbonate (PADC) plastic. It presents information on the problems to be expected based on data from calibrations of actual personal neutron dosemeters in terms of the existing dose quantities., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
50. Results and analysis of an intercomparisons study for individual monitoring services of Latin American and Caribbean regions.
- Author
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Khoury H, Menchaca I, Andres P, de Barros V, Silva E, Alonso T, Molina D, Noguera G, Videla R, Rubio J, Bastidas B, Quintero C, Castillo R, Castillo A, Kawas N, Grant C, Garcia AL, Martinez E, Mora J, and Suarez RC
- Subjects
- Humans, Caribbean Region, Latin America, Radiation Dosage, Occupational Exposure analysis, Radiation Monitoring methods, Radiation Protection methods
- Abstract
The aim of this paper is to present the results obtained by the Latin-American and Caribbean personal dosimetry services that participated, with the support of IAEA, in the 2020-Eurados whole-body dosemeter intercomparison for photon radiation. All participant services in this study use thermoluminescent dosimetry (TLD) systems except one that uses optically stimulated luminescence (OSL) dosemeters. Data analysis shows that 93.4% of the results are within the acceptance range, according to International ISO Standard ISO 14146: 2018. The evaluation of the trumpet curves shows that only three laboratories presented a few dosemeters results outside the limits of acceptability. Participation in this Eurados intercomparison exercise gave the Latin American and Caribbean laboratories the opportunity to show compliance with their own quality management system, to compare results with other participants and to develop plans for improving their dosimetry systems. It also gave the assurance that occupational doses are being measured properly and following the international standards in the regions., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
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