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Objective: The aim of this study is to investigate the cellular, molecular, genetic and non-invasive functional biomarkers of occupational irradiation in workers exposed to a combination of external gamma-radiation and incorporation of transuranium elements. Results: A study was performed in 688 radiation workers of Shelter object conversion into a safe system with mean shift dose of external exposure of 26.06 mSv (range: 0.1–113.35) and risk of internal exposure with transuranium elements. Several biological parameters could serve as biomarkers of exposure at radiation doses below 100 mSv and even in 20–50 mSv interval. The parallel changes were shown in decline of brain electric activity, telomere length, differences in CCND1, CDKN1A, CDKN2A, VEGFA, TP53, DDB2 genes expression. An increase in counts of dicentrics, pair fragments and TCR-variant lymphocytes at doses over professional limits shows the need of biological dosimetry. The most sensitive markers include TCR-CD4+, γ-H2AX+ and CyclinD1+ cell counts. Implementation of flow cytometry approach for these markers enables quick obtaining of quantitative data. Confounding factors included respiratory function and smoking. The study of the radiation workers with the history of chronic exposure in radiation area during 3–5 years demonstrates changes of compensatory origin, i.e. absence of telomere shortening, increased number of NK-cells in combination with lower expression of intracellular γ-H2AX. Conclusion: This study confirms the presence of radiation-induced changes in gene regulation of cell proliferation, telomere function and apoptosis in radiation workers exposed to external and internal exposure at doses above professional limits and increase of compensatory changes. [ABSTRACT FROM AUTHOR]

To assess the health statue of chronically exposed Chinese medical radiation workers. A cross-sectional study of 530 medical radiation workers in a city of China was conducted to document the health status and the monitored annually absorbed doses. Long-term and low-dose radiation exposure can affect a number of health indicators in the individuals, which covered the cardiovascular system, hematologic system, ophthalmology, liver and kidney's functions, chromosome aberration and micronucleus. The differences in the health status between male and female individuals were associated with job types and exposed years of service. The monitored doses of individuals were lower than the limit value of the national standard. The health status in chronically exposed individuals demonstrated some gender difference associated with length of exposure and work type. This study provides some evidence to understand the health status of medical radiation workers in China and have the potentially to inform screening and clinical diagnosis. [ABSTRACT FROM AUTHOR]

The effective implementation of a comprehensive quality assurance (QA) programme in any individual monitoring service plays a key role in attaining and sustaining the level of performance at par with international standards. In India, individual monitoring of more than 120 000 radiation workers is provided through 16 laboratories using a CaSO4:Dy based thermoluminescence dosimetry (TLD) badge system. In such a wide-spread programme, the harmonization of procedures and regular QA check on the dosimetry system are utmost important to ensure the uniform standard of accuracy and reliability of the service. This paper discusses some aspects of the QA programme implemented at different stages of the TLD monitoring system and provides the results of the performance test of monitoring laboratories. [ABSTRACT FROM AUTHOR]

Individual monitoring for both external and internal exposures is well regulated in Switzerland. The article gives an overview on the occupational exposure to external radiation of workers based on the data collected in the Swiss national dose registry (NDR) in 2013. The NDR records the monthly doses of radiation workers since the introduction of ICRP 60 recommendations and is manifested in the Swiss ordinance since 1994. Annual dose limits for effective dose are typically exceeded once a year in Switzerland, mostly in medicine. The NDR is a useful optimisation tool to identify and characterise areas with the highest exposures. While exceeded dose limits were often related to accidental acute exposure in the past, they are now more related to continuous exposure during normal work, especially in medicine. [ABSTRACT FROM AUTHOR]

In recent years, a new national Dose Register has been under development in Finland. This article presents this work, the challenges in the project, the features of the new register and experiences in using it. There were several motivations for creating a new register. The technical implementation of the existing Dose Register needed to be reformed, and there was also a need to improve electronic communication and access to the recorded data. The development was challenging and took more time and effort than expected. Despite the challenges, the new system works quite reliably and enables the use of the registered data to more easily improve radiation safety. [ABSTRACT FROM AUTHOR]

Investigations are sometimes required to verify dose assessments or, where the reliability of the original results is known to be in question, to replace them with an estimate of the dose. In Finland, such investigations are conducted by three different parties: the Radiation and Nuclear Safety Authority (STUK), the individual monitoring service (IMS) and the parties operating a radiation practice (the undertakings). The reasons for such investigations as well as the findings from them vary widely between different parties. To determine their usefulness, all investigations carried out on Finnish radiation workers by the STUK, the IMS and the undertakings during 2004-13 have been reviewed. This paper presents the number, reasons for and findings of these investigations. The effect of the investigations on the recorded individual doses as well as on the working methods and other aspects of radiation protection in the work environment are described. [ABSTRACT FROM AUTHOR]

United States Air Force (USAF) aircrew fly at altitudes and for durations where doses from cosmic radiation are significant enough to warrant monitoring. This study evaluated a candidate radiological monitoring system for USAF aircrew, the Thermo Scientific electronic personnel dosemeter (EPD-N2). The evaluation consisted of characterising the device in a well-characterised radiation field at a European Organization for Nuclear Research (CERN) accelerator, and aboard an USAF aircraft. The performance of the EPDs was evaluated by comparison with accepted values for dose at the CERN facility, comparison with the value calculated by flight dose software and comparison with the value estimated by a tissue-equivalent proportional counter aboard the aircraft. This study recommends that a correction factor of 1/CF = 1/3.9 be applied to EPD-N2 measurements aboard aircraft flights. The uncertainty in this correction factor is 11.8 %. [ABSTRACT FROM PUBLISHER]

The European Radiation Dosimetry Group (EURADOS) IC2012n intercomparison for neutron dosemeters intended to measure personal dose equivalent, Hp(10), was performed in 2012. A total of 31 participants (27 individual monitoring services from Europe, 2 from Japan, 1 from Israel and 1 from USA) registered with 34 dosimetry systems. Participation was restricted to passive or active neutron dosemeters routinely used in individual monitoring of radiation workers. The dosimetry systems were based on thermoluminescence, polyallyldiglycol carbonate, optically stimulated luminescence, fission track detection and silicon diodes (electronic devices). The irradiation tests were chosen to provide the participants with useful information on their dosimetry systems, i.e. linearity, reproducibility, responses for different energies and angles and to simulated workplace fields. The paper will report and discuss the first analysis of the results of the EURADOS IC2012n intercomparison. [ABSTRACT FROM AUTHOR]

The occupational radiation exposure of medical radiation workers at the Institute of Oncology, Vilnius University (IOVU) was analysed. Quartile dose measurements were collected and routinely analysed for a period of 8 y from 1 January 2004 to 31 December 2011. A total of 193 medical radiation workers were monitored, comprising 34 % physicians (radiologists and radiotherapists), 8 % physicists, 42 % radiological technologists and 16 % ancillary staff. A statistically significant decrease by 18 % has been detected when comparing the annual average effective doses (AAEDs) received by medical radiation workers at the IOVU during periods 2004–2007 and 2008–2011 (p < 0.0001). The main occupation categories responsible for this reduction were of Nuclear Medicine (p < 0.028) and Radiology (p < 0.0001) departments. The values of AAED in Radiology, Radiotherapy and Nuclear Medicine departments are quite low and well below the annual limit of 20 mSv, averaged over a period of 5 consecutive years. [ABSTRACT FROM AUTHOR]

A personal dosimetry service that evaluates the occupational doses for external and internal radiation of the radiation workers is one of the main components of radiation protection programme. The education and training (E&T) activities in this field are basic aspects of the optimisation of all exposures to radiation. The E&T activities in the field of occupational radiation protection at the national and international level are of main interest and implemented by the Ankara Nuclear Research and Training Center. This study describes the Turkish experience in E&T of the staff of dosimetry services, postgraduate students and medical physics experts. In Turkey, the first individual monitoring training course was conducted in 2012. The aim of this study is to provide a structured description of postgraduate courses that are addressed to qualified experts and medical physics experts, and the modules are mainly dedicated to individual monitoring. [ABSTRACT FROM AUTHOR]

During a maintenance period at a Korean nuclear power plant, internal exposure of radiation workers occurred by the inhalation of 131I that was released into the reactor building from a primary system opening due to defective fuels. The internal activity in radiation workers contaminated by 131I was immediately measured using a whole body counter (WBC). A whole body counting was performed again a few days later, considering the factors of equilibrium in the body. The intake and the committed effective dose were estimated based on the WBC results. The intake was also calculated by hand, based on both the entrance records to the reactor building, and the counted results of the air concentration for 131I were compared with the whole body counting results. [ABSTRACT FROM AUTHOR]

The monetary value of the man-mSv for operators of Korean nuclear power plants (NPPs) was calculated using a radiation aversion factor based on a survey of NPP workers. Initially, the life expectancy in the population is 79.4 y, the average age of cancer occurrence is 60 y, the average annual wage for an electric worker is 56 000 $ y−1 and the nominal risk coefficient induced by radiation is 4.2E−5 mSv were used to evaluate the basic monetary value (αbase) resulting in 45.6 $ mSv−1. To investigate the degree of radiation aversion, the subject of the investigation was selected as the working radiation workers in 10 NPPs in Korea (Kori 1–2, Yeonggwang 1–3, Ulchin 1–3 and Wolseong 1–2). In August 2010, with the cooperation of KHNP and partner companies, a total of 2500 survey questionnaires to 10 NPPs (or 250 surveys to each NPP) were distributed to currently employed radiation workers. From these, 2157 responses were obtained between August and October 2010. The assessed radiation aversion factor and the monetary value of the man-mSv from the calculated radiation aversion factor were 1.26 and ∼50 $ in the 0–1 mSv range, 1.38 and ∼200 $ in the 1–5 mSv range, 1.52 and ∼1000 $ in the 5–10 mSv range, 1.65 and ∼4000 $ in the 10–20 mSv range and 1.74 and ∼8500 $ >20 mSv. [ABSTRACT FROM AUTHOR]

Personnel monitoring of radiation workers in India is carried out using a thermoluminescence dosemeter (TLD) system based on CaSO4:Dy Teflon TLD disc. The dose due to occupational exposure for a majority of radiation workers is very small and hence is reported as zero. In view of this the detection of low levels of occupational dose over and above a variable background assumes great importance. The present values of reporting levels are based on the standard deviations of annealed dosemeters and therefore are fixed irrespective of period of use and background radiation levels. The validity of these levels is investigated under laboratory conditions. The laboratory values of standard deviations cannot be used as an indication of the imprecision that occurs during service. Therefore, the validity of the reporting levels is also investigated for control dosemeters used in routine service. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the use of common external image processing to compensate for differences in appearance between digital X-ray images from different vendors. Twenty posteroanterior chest radiographs were collected from each of three different modalities from different vendors (GE, Siemens and Canon) with vendor-specific image processing applied. The images were also extracted with neutral process parameters and processed with external image-processing software. Six experienced radiologists rated the quality and the similarity of the images with the original Siemens images. The externally processed GE images were rated of higher quality than the original GE images and more similar to the original Siemens images (p < 0.001). The opposite was obtained for the Canon images. The externally processed Siemens images were rated of similar quality as the original images. The present study indicates the possibility of using common external image processing to harmonise the appearance of images from different vendors, although the exposure parameters may need to be adjusted for individual vendors. [ABSTRACT FROM PUBLISHER]

The purpose of the present study was to compare the diagnostic accuracy of dual-view digital mammography (DM), single-view breast tomosynthesis (BT) and BT combined with the opposite DM view. Patients with subtle lesions were selected to undergo BT examinations. Two radiologists who are non-participants in the study and have experience in using DM and BT determined the locations and extents of lesions in the images. Five expert mammographers interpreted the cases using the free-response paradigm. The task was to mark and rate clinically reportable findings suspicious for malignancy and clinically relevant benign findings. The marks were scored with reference to the outlined regions into lesion localization or non-lesion localization, and analysed by the jackknife alternative free-response receiver operating characteristic method. The analysis yielded statistically significant differences between the combined modality and dual-view DM (p < 0.05). No differences were found between single-view BT and dual-view DM or between single-view BT and the combined modality. [ABSTRACT FROM PUBLISHER]

There are many ways in which imaging systems can be evaluated. The aim of the present paper is to provide an overview of a number of selected approaches to evaluating imaging systems, often encountered by the medical physicist, and discuss their validity and reliability. Specifically, it will cover (i) characterisation of an imaging system in terms of its detective quantum efficiency using linear-systems analysis; (ii) attempts to calculate relevant measures directly in images using the Rose model and the pixel signal-to-noise ratio; (iii) task-based methods incorporating human observers such as receiver-operating characteristics and (iv) visual grading-based methods using experienced radiologists as observers. [ABSTRACT FROM PUBLISHER]

The purpose of the present work was to optimise the filtration and dose setting for double-contrast barium enema examinations using a Philips MultiDiagnost Eleva FD system. A phantom study was performed prior to a patient study. A CDRAD phantom was used in a study where copper and aluminium filtration, different detector doses and tube potentials were examined. The image quality was evaluated using the software CDRAD Analyser and the phantom dose was determined using the Monte Carlo-based software PCXMC. The original setting [100 % detector dose (660 nGy air kerma) and a total filtration of 3.5 mm Al, at 81 kVp] and two other settings identified by the phantom study (100 % detector dose and additional filtration of 1 mm Al and 0.2 mm Cu as well as 80 % detector dose and added filtration of 1 mm Al and 0.2 mm Cu) were included in the patient study. The patient study included 60 patients and up to 8 images from each patient. Six radiologists performed a visual grading characteristics study to evaluate the image quality. A four-step scale was used to judge the fulfilment of three image quality criteria. No overall statistical significant difference in image quality was found between the three settings (P > 0.05). The decrease in the effective dose for the settings in the patient study was 15 % when filtration was added and 34 % when both filtrartions was added and detector dose was reduced. The study indicates that additional filtration of 1 mm Al and 0.2 mm Cu and a decrease in detector dose by 20 % from the original setting can be used in colon examinations with Philips MultiDiagnost Eleva FD to reduce the patient dose by 30 % without significantly affecting the image quality. For 20 exposures, this corresponds to a decrease in the effective dose from 1.6 to 1.1 mSv. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate the possibility of reducing the radiation dose to paediatric patients undergoing computed tomography (CT) brain examination by using image-enhancing software. Artificial noise was added to the raw data collected from 20 patients aged between 1 and 10 y to simulate tube current reductions of 20, 40 and 60 mA. All images were created in duplicate; one set of images remained unprocessed whereas the other was processed with image-enhancing software. Three paediatric radiologists assessed the image quality based on their ability to visualise the high- and low-contrast structures and their overall impression of the diagnostic value of the image. For patients aged 6–10 y, it was found that dose reductions from 27 mGy (CTDIvol) to 23 mGy (15 %) in the upper brain and from 32 to 28 mGy (13 %) in the lower brain were possible for standard diagnostic CT examinations when using the image-enhancing filter. For patients 1–5 y, the results for standard diagnostics in the upper brain were inconclusive, for the lower brain no dose reductions were found possible. [ABSTRACT FROM PUBLISHER]

With the increasing use of computed tomography (CT) for urography examinations, the indications for ‘conventional’ projection urography have changed and are more focused on high-contrast details. The purpose of the present study was to optimise the beam quality for urography examinations performed with a Gd2O2S:Tb flat-panel detector for the new conditions. Images of an anthropomorphic phantom were collected at different tube voltages with a CXDI-40G detector (Canon Inc., Tokyo, Japan). The images were analysed by radiologists and residents in a visual grading characteristics (VGCs) study. The tube voltage resulting in the best image quality was 55 kV, which therefore was selected for a clinical study. Images from 62 patients exposed with either 55 or 73 kV (original tube voltage) at constant effective doses were included. The 55-kV images underwent simulated dose reduction to represent images collected at 80, 64, 50, 40 and 32 % of the original dose level. All images were included in a VGC study where the observers rated the visibility of important anatomical landmarks. For images collected at 55 kV, an effective dose of ∼85 % resulted in the same image quality as for images collected at 73 kV at 100 % dose. In conclusion, a low tube voltage should be used for conventional urography focused on high-contrast details. The study indicates that using a tube voltage of 55 kV instead of 73 kV for a Gd2O2S:Tb flat-panel detector, the effective dose can be reduced by ∼10–20 % for normal-sized patients while maintaining image quality. [ABSTRACT FROM PUBLISHER]

The purpose of the present study was to investigate if the exposure could be reduced from the clinical setting (resulting in an effective dose of 8 µSv for a neonate of weight 0.7 kg and height 25 cm at a tube voltage of 90 kV) without negatively influencing the image quality for a dual-side readout technique computed radiography (CR) system in chest radiography of premature neonates. Chest radiographs of premature neonates were acquired with the double-side readout technique CR system. The images underwent simulated dose reduction in steps of 20 % to represent five different radiation dose levels. Four image quality criteria, related to the visibility of important anatomical structures, were used in a visual grading study where five experienced radiologists rated how well the criteria were fulfilled for all images. When reducing the radiation dose, a decrease in image quality could be observed already at the 80 % dose level for all the structures. The results indicate that a decrease in exposure from the clinically used setting affects the image quality negatively for the CR system. [ABSTRACT FROM PUBLISHER]

Direct measurements of seven highly exposed workers at the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station accident have been performed continuously since June 2011. Caesium clearance in the monitored workers is in agreement with the biokinetic models proposed by the International Commission on Radiological Protection. After 500 d from the initial measurement, however, the caesium clearance slowed. It was thought to be unlikely that additional Cs intake had occurred after the initial intake, as activity in foods was kept low. And, the contribution from the detector over the chest was enhanced with time. This indicates that insoluble Cs particles were inhaled and a long metabolic rate showed. [ABSTRACT FROM AUTHOR]

This paper presents a pilot study in which specific activities of 14C in hair and urine from 11 radiation workers handling 14C-containing substances have been measured using accelerator mass spectrometry. Varying degrees of contamination were revealed: up to 63% excess in hair and 400% excess in urine. Although the 14C excess reported in this study would result in low effective doses, it would be of interest to monitor the situation at other workplaces with potentially higher risks of contamination. Simultaneous measurements of 14C in hair and urine with additional random measurements of 14C in faeces and exhaled air could provide a means of improving dose estimates for workers handling different types of 14C-containing substances. [ABSTRACT FROM AUTHOR]

This study presents the summary of historical exposures, measurement practice and evolution of the recording of the individual doses of medical radiation workers during 1950-2003 in Lithuania. The aim of this study is to present occupational exposure of medical radiation workers in Lithuania since the earliest appearance period. Data from publications have been used for the earliest two periods prior to 1969; data from the archives of the largest hospitals, for the period 1970-1990 and data from Lithuanian Subdivision of Individual Dosimetry of Radiation Protection Center, for the period 1991-2003. The analysis of the data obtained from personal records allows to conclude that the average annual effective dose of Lithuanian medical radiation workers was greatly reduced in radiology, radiotherapy and nuclear medicine in all occupational categories from 1950 to 2003. During the last period 1991-2003 extremity doses clearly decreased and after 1994 were no longer present in Lithuania. [ABSTRACT FROM AUTHOR]

Beta emitters are widely used in nuclear medicine for diagnostic and therapeutic purposes. The critical groups exposed to a radioactive patient include the staff, other patients and members of the public accompanying the patient. The aim of this work is to characterise thermoluminescent (TL) materials for the staff monitoring of nuclear medicine services that manipulate beta radiation solutions of 153Sm. This study was performed using CaSO4:Dy + Teflon pellets, produced at IPEN, with different dimensions. For the dosimetric characterisation, these TL dosemeters were exposed to gamma source (60Co) and to beta sealed sources (90Sr + 90Y, 204TI and 147Pm) and to a non-sealed source (153Sm). Results were obtained related to reproducibility, lower detection limits, calibration curves, angle and energy dependence of response. All tested materials show usefulness for monitoring of workers exposed to beta radiation. [ABSTRACT FROM AUTHOR]

Among the activities of EURADOS Working Group 2 formed by experts from several European countries is the harmonisation of individual monitoring as part of radiation protection of occupationally exposed persons. Here, we provide information about thermoluminescent detectors (TLDs) applied by the European dosimetric services and the dosimetric characteristics of dosemeters in which these detectors are applied. Among 91 services from 29 countries which responded to the EURADOS questionnaire, 61 apply dosemeters with TLDs for the determination of personal dose equivalent Hp(10) for photons and beta radiation, and 16 services use TLDs for neutron albedo dosemeters. Those most frequently used are standard lithium fluoride TLDs (mainly TLD-100, TLD-700, Polish MTS-N and MTS-7, Russian DTG-4), high-sensitive lithium fluoride (GR-200, MCP-N) and lithium borate TLDs. Some services use calcium sulphate and calcium fluoride detectors. For neutron dosimetry, most services apply pairs of LiF:Mg,Ti TLDs with 6Li and 7Li. The characteristics (energy response) of individual dosemeters are mainly related to the energy response of the detectors and filters applied. The construction of filters in dosemeters applied for measurements of Hp(10) and their energy response are also reviewed. [ABSTRACT FROM AUTHOR]

In India, ∼58,000 radiation workers are monitored using locally made CaSO4:Dy teflon embedded thermoluminescence dosemeter (TLD) badge system. The automatic hot gas readers developed locally are also used in TL measurements. The hot gas reader system has many advantages over the manual readers used previously and has completely replaced the manual reader system in all TLD personnel monitoring units in India. In the present study, the new reader system is studied and a theoretical attempt has been made to interpret the experimentally obtained results. The glow curves are generated theoretically and are also plotted experimentally. It has been found that the heat capacity of the heating gas, which is responsible for the transfer of heat, has a role in deciding the position of peak and is verified experimentally using different gas flow rates of nitrogen and argon as heating gases in the reader. The theoretical study may also be helpful in fitting the experimentally obtained glow curves and, therefore, the elimination of unwanted non-radiation-induced contributions, such as dark current, electronic spikes, light leakage and triboluminescence that generally distort the glow curve shape, can be achieved. [ABSTRACT FROM AUTHOR]

Monitoring of occupationally exposed persons in Bosnia and Herzegovina started in 1960s and it was interrupted in 1992. Dosimetry service resumed in 1999 when the International Atomic Energy Agency provided Harshaw 4500 TLD-reader and the first set of TLDs for the Radiation Protection Centre (RPC) of the Institute of Public Health of the Federation of Bosnia and Herzegovina. In January 2009, the RPC covered 1279 professionals with personal dosimetry, which is more than 70 % of all radiation workers in the country. Most of the TLD users work in medical institutions. In period 1999–2003 RPC provided 984 workers with dosemeters. In the next 5 y period (2004–2008), the number of persons covered by dosimetry increased by an average of 51 %. The mean and collective effective dose in the period 1999–2003 were 1.55 mSv and 1.54 personSv, respectively. In the period 2004–2008, the mean doses changed by 1 % on average, but the collective effective dose increased by 53 % for all practices. Mean and collective effective dose were 1.57 mSv and 2.34 personSv, respectively. The highest personal doses are associated with industrial radiography, than exposures in nuclear medicine. Radiology plays a significant role in collective dose only, whereas other exposures are low. Results correspond to results found in the literature. New practices in industry and medicine emphasise the need for more personal dosemeters, as well as specialised dosemeters for extremities monitoring, etc. [ABSTRACT FROM PUBLISHER]