| 1. |
- Isaksson, Mats, 1961, et al.
(författare)
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Absorbed dose rate coefficients for 134Cs and 137Cs with steady-state distribution in the human body : S-coefficients revisited
- 2021
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Ingår i: Journal of Radiological Protection. - : Institute of Physics Publishing (IOPP). - 0952-4746 .- 1361-6498. ; 41:4, s. 1213-1227
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Tidskriftsartikel (refereegranskat)abstract
- In the event of an accidental release of radioactive elements from a nuclear power plant, it has been shown that the radionuclides contributing the most to long-term exposure are Cs-134 and Cs-137. In the case of nuclear power plant fallout, with subsequent intake of radionuclides through the food chain, the internal absorbed dose to target tissues from protracted intake of radionuclides needs to be estimated. Internal contamination from food consumption is not caused by a single intake event; hence, the committed equivalent dose, calculated by a dose coefficient or dose per content function, cannot be easily used to calculate the cumulative absorbed dose to relevant target tissues in the body. In this study, we calculated updated absorbed dose rate coefficients for Cs-134 and Cs-137 based on data from the International Commission on Radiological Protection (ICRP) on specific absorbed fractions. The absorbed dose rate coefficients are provided for male and female adult reference phantoms, respectively, assuming a steady-state distribution of Cs that we calculated from the ICRP biokinetic model for Cs. With these coefficients, the absorbed dose to the listed target tissues, separately and to the total body, are related to the number of nuclear transitions (time-integrated activity) in each listed source region. Our new absorbed dose rate coefficients are given for the complete set of target tissues and have not been presented before. They are also provided for aggregated categories of organs to facilitate epidemiological studies.
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| 2. |
- Lagergren Lindberg, Marita, et al.
(författare)
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Mental health and psychosocial consequences linked to radiation emergencies - Increasingly recognised concerns
- 2022
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 42:3
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Forskningsöversikt (refereegranskat)abstract
- A major radiological or nuclear emergency may, apart from causing a substantial loss of life and physical damage, also put a substantial strain on affected societies with social, economic and political consequences. Although such emergencies are relatively uncommon, it is now being increasingly recognised that their subsequent psychosocial impact can be widespread and long lasting. Mental health effects, such as depression, anxiety and post-traumatic stress disorder, are highly represented in a population affected by a radiation disaster. In order to reach the majority of the people affected by radiation accidents, we need to be aware of how to distribute relevant and accurate information related to both short- and long-term medical effects. Effective risk communication is associated with improved compliance with any given recommendations. It is important to protect the public from physical radiation damage, but it is also essential to take into account the social and mental health effects that radiation disasters may induce. This article provides a brief review of recent reporting on the psychological consequences after a major radiation emergency.
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| 3. |
- O'Connor, U, et al.
(författare)
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Feasibility study of computational occupational dosimetry : evaluating a proof-of-concept in an endovascular and interventional cardiology setting
- 2022
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 1361-6498 .- 0952-4746. ; 42:4
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Tidskriftsartikel (refereegranskat)abstract
- Individual monitoring of radiation workers is essential to ensure compliance with legal dose limits and to ensure that doses are As Low As Reasonably Achievable. However, large uncertainties still exist in personal dosimetry and there are issues with compliance and incorrect wearing of dosimeters. The objective of the PODIUM (Personal Online Dosimetry Using Computational Methods) project was to improve personal dosimetry by an innovative approach: the development of an online dosimetry application based on computer simulations without the use of physical dosimeters. Occupational doses were calculated based on the use of camera tracking devices, flexible individualised phantoms and data from the radiation source. When combined with fast Monte Carlo simulation codes, the aim was to perform personal dosimetry in real-time. A key component of the PODIUM project was to assess and validate the methodology in interventional radiology workplaces where improvements in dosimetry are needed. This paper describes the feasibility of implementing the PODIUM approach in a clinical setting. Validation was carried out using dosimeters worn by Vascular Surgeons and Interventional Cardiologists during patient procedures at a hospital in Ireland. Our preliminary results from this feasibility study show acceptable differences of the order of 40% between calculated and measured staff doses, in terms of the personal dose equivalent quantity Hp(10), however there is a greater deviation for more complex cases and improvements are needed. The challenges of using the system in busy interventional rooms have informed the future needs and applicability of PODIUM. The availability of an online personal dosimetry application has the potential to overcome problems that arise from the use of current dosimeters. In addition, it should increase awareness of radiation protection among staff. Some limitations remain and a second phase of development would be required to bring the PODIUM method into operation in a hospital setting. However, an early prototype system has been tested in a clinical setting and the results from this two-year proof-of-concept PODIUM project are very promising for future development.
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| 4. |
- Rääf, C., et al.
(författare)
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Averting cumulative lifetime attributable risk (LAR) of cancer by decontamination of residential areas affected by a large-scale nuclear power plant fallout: Time aspects of radiological benefits for newborns and adults
- 2020
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 40:3, s. 790-814
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Tidskriftsartikel (refereegranskat)abstract
- The averted cumulative lifetime attributable risk (LAR), the residual dose and highest ground deposition of 137Cs complying with a reference dose level of 20 mSv y-1 to an individual returning after one year to an area contaminated by nuclear power plant (NPP) fallout were evaluated by applying an existing exposure model designed to compute age- and gender-dependent time integrated LAR. The model was applied to four types of nuclear fallout scenarios, partly based on data from the Chernobyl and Fukushima releases and from theoretical source terms from Swedish NPPs. For rapid decontamination measures that achieve a 50% relative reduction in external dose rate within 1 y, compliance with the reference level 20 mSv y-1 can be attained for an initial 137Cs ground deposition of up to 2 MBq m-2 with relaxed food restrictions. This compliance can be attained at even higher ground deposition (up to 3.5 MBq m-2) if using the strict food restrictions employed in Japan after 2011. Considering longer than 1 year return times it was also found that the benefit of implementing decontamination decreases rapidly with time (2-3 y half-time), especially if the fallout has a high initial 134Cs to 137Cs activity ratio and if the ecological half-time of the external dose rate is short (<5 y). Depending on fallout scenario the averted cumulative LAR for newborn girls by decontamination that is achieved after 5 y is only between 6% and 11% of that obtained by evacuation alone during the same time, indicating a rather limited radiological benefit of decontamination if delayed more than a few years. We conclude that decision makers and emergency response planners need to consider that protracted decontamination measures may have limited radiological benefit compared with evacuation in terms of averted future cancer cases, albeit it may have other societal benefits.
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| 5. |
- Waldner, Lovisa, et al.
(författare)
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Experimentally determined and Monte Carlo-calculated energy dependence of NaCl pellets read by optically stimulated luminescence for photon beams in the energy range 30 keV to 1.25 MeV
- 2020
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 40:4, s. 1321-1335
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Tidskriftsartikel (refereegranskat)abstract
- Ordinary salt, NaCl, has many properties suitable for dosimetry and has been suggested for both retrospective and prospective optically stimulated luminescence (OSL) dosimetry. Lately, the focus has been on NaCl that is compressed into solid pellets, as this improves both its handling and dosimetric properties. In this project, the energy dependence of NaCl pellets produced in-house was investigated for photon energies between 30 and 1.25 MeV. The NaCl pellets were first exposed to free-in-air conditions, and the estimated absorbed dose to the NaCl pellets was compared to the air kerma, K air, at the point of exposure. Second, a backscatter medium of polymethyl methacrylate (PMMA) was added, and NaCl pellets were exposed when positioned on a ISO slab phantom to relate the response in the NaCl to the personal dose equivalent, H p(10). The results show a significant energy dependence for exposure to low-energy photons with a peak over-response compared to K air and H p(10) of up to 18. Comparisons with Monte Carlo simulations show good agreement, even though the simulations cannot account for properties related to the intrinsic luminescence effects of the NaCl pellets or the readout and calibration process. The finite thickness of the NaCl pellet makes it an imperfect Bragg-Grey cavity, which complicates the behaviour of the energy dependence. The results presented here may serve as an important basis for further experimental and theoretical modelling of a build-up layer and filters in efforts to develop a passive personal dosemeter based on NaCl.
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| 6. |
- Bazzi, May, 1979, et al.
(författare)
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Factors affecting radiographers' use of dose-reduction measures
- 2024
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Ingår i: JOURNAL OF RADIOLOGICAL PROTECTION. - : Institute of Physics (IOP). - 0952-4746 .- 1361-6498. ; 44:1
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates radiographers' views on implementing dose-reduction measures, with a focus on verifying patient identity and pregnancy status, practising gonad shielding in men and using compression. An electronic questionnaire was distributed to radiographers working in general radiography and/or computed tomography. The questionnaire was based on factors from a framework for analysing risk and safety in clinical medicine. Ordered logistic regressions were used to analyse associations among factors and use of dose-reduction measures. In total, 466 questionnaires were distributed and 170 radiographers (36%) completed them. Clear instructions and routines, support from colleagues, knowledge and experience, a strong safety culture, managerial support and access to proper equipment influence the likelihood of using dose-reduction measures. The strongest associations were found between support from colleagues and verifying pregnancy status (OR = 5.65, P = 0.026), safety culture and use of gonad shielding (OR = 2.36, P = 0.042), and having enough time and use of compression (OR = 2.11, P = 0.003). A strong safety culture and a supportive work environment appears to be essential for the use of dose-reduction measures, and education, training and stress management can improve utilisation of dose-reduction measures.
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| 7. |
- Hjellström, Martin, 1993, et al.
(författare)
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Medical gamma cameras in radiological emergency preparedness: determination of calibration factors and MDA for the GE Discovery NM/CT 670 Pro.
- 2023
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Ingår i: Journal of radiological protection : official journal of the Society for Radiological Protection. - : IOP Publishing. - 1361-6498. ; 43:1
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Tidskriftsartikel (refereegranskat)abstract
- A survey was performed of the available gamma camera models and whole-body counters (WBCs) in Sweden, revealing that there are about 75 gamma cameras and 15 WBCs currently in operation in Sweden. One of the most common gamma camera models (GE Discovery NM/CT 670 Pro), with the collimators removed, was calibrated for Eu-152, Cs-137, Co-60 and K-40 in three different measurement geometries (supine, close-up sitting and distant sitting) for six different phantom sizes (12-110 kg). Minimum detectable activities (MDAs) were calculated for the gamma camera and a typical WBC, both at the Sahlgrenska University Hospital in Gothenburg, Sweden. An energy window of 30-510 keV was used to calibrate the gamma camera. The calibration factors for this gamma camera for supine and close-up sitting geometry, including all phantom sizes, were 138-208 cps/kBq for Eu-152, 63-83 cps/kBq for Cs-137 and 99-126 cps/kBq for Co-60; the MDAs were 50-73 Bq for Eu-152, 125-198 Bq for Cs-137 and 83-105 Bq for Co-60. The International Commission on Radiological Protection dose coefficients for members of the public were used to calculate the committed effective doses (CEDs) corresponding to the MDAs, showing that CEDs down to a fewμSv can be estimated with this gamma camera for the inhalation of aerosols of absorption type M. The distant sitting geometry was used to enable the estimation of higher contamination levels, and a hypothetical maximum CED was calculated. This was shown to be 256-2000 mSv, depending on the radionuclide and phantom size. However, further investigations are needed into the dead time losses for higher activity levels for the radionuclides studied. The results show that the use of gamma cameras for radiological triage and, in some cases, to estimate the internal activity of relevant radionuclides in radiological and nuclear events, is feasible.
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| 8. |
- Lundvall, Liselotte, et al.
(författare)
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Occupational doses in interventional angiography after radiological protection training and use of a real-time direct display dosimeter
- 2022
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Ingår i: Journal of Radiological Protection. - : IOP Publishing Ltd. - 0952-4746 .- 1361-6498. ; 42:3
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Tidskriftsartikel (refereegranskat)abstract
- Vascular x-ray guided interventions are complex and may result in high occupational doses to ionising radiation if staff do not take appropriate actions to minimise their exposure. In this prospective intervention study, ten staff members wore an extra personal dosimeter on the upper body above their regular protective clothing during four consecutive periods. Between each period either additional practical radiological protection training was given or a real-time direct display dosimeter were provided to the staff. Each staffs personal dose equivalent, Hp(10) normalised to the total air kerma-area product for the procedures where each staff were involved, KAPt, was used as the dependent variable. A focus-group interview with the staff were performed about the usefulness of the training and real-time dose rate display system. Our aim was to investigate if the interventions (practical training or real-time dose rate display) did affect the staff doses in the short and long term (five months later). Significant (p < 0.05) reductions of staff doses Hp(10)/KAPt were found after practical radiological protection training, but not after using real-time dose rate displays. Significant reductions were maintained after five months without additional interventions. The results from the focus-group interview indicated that making radiation visible, during practical training and usage of real-time direct display dosimeter, made it easier to understand how to act to lower occupational doses.
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| 9. |
- Nocum, D. J., et al.
(författare)
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Predictors of radiation dose for uterine artery embolisation are angiography system-dependent
- 2022
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 42:1
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Tidskriftsartikel (refereegranskat)abstract
- This study sought to achieve radiation dose reductions for patients receiving uterine artery embolisation (UAE) by evaluating radiation dose measurements for the preceding generation (Allura) and upgraded (Azurion) angiography system. Previous UAE regression models in the literature could not be applied to this centre's practice due to being based on different angiography systems and radiation dose predictor variables. The aims of this study were to establish whether radiation dose is reduced with the upgraded angiography system and to develop a regression model to determine predictors of radiation dose specific to the upgraded angiography system. A comparison between Group I (Allura, n = 95) and Group II (Azurion, n = 95) demonstrated a significant reduction in kerma-area product (KAP) and Ka, r (reference air kerma) by 63% (143.2 Gy cm(2) vs 52.9 Gy cm(2); P < 0.001, d = 0.8) and 67% (0.6 Gy vs 0.2 Gy; P < 0.001, d = 0.8), respectively. The multivariable linear regression (MLR) model identified the UAE radiation dose predictors for KAP on the upgraded angiography system as total fluoroscopy dose, Ka, r, and total uterus volume. The predictive accuracy of the MLR model was assessed using a Bland-Altman plot. The mean difference was 0.39 Gy cm(2) and the limits of agreement were +28.49 and -27.71 Gy cm(2), and thus illustrated no proportional bias. The resultant MLR model was considered system-dependent and validated the upgraded angiography system and its advance capabilities to significantly reduce radiation dose. Interventional radiologist and interventional radiographer familiarisation of the system's features and the implementation of the newly established MLR model would further facilitate dose optimisation for all centres performing UAE procedures using the upgraded angiography system.
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| 10. |
- Rühm, W., et al.
(författare)
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Summary of the 2021 ICRP workshop on the future of radiological protection
- 2022
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Ingår i: Journal of Radiological Protection. - : IOP Publishing. - 0952-4746 .- 1361-6498. ; 42:2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The International Commission on Radiological Protection (ICRP) has embarked on a process to review and revise the current System of Radiological Protection ('the System'). To stimulate discussion, the ICRP published two open-access articles: one on aspects of the System that might require review, and another on research that might improve the scientific foundation of the System. Building on these articles, the ICRP organized a Workshop on the Future of Radiological Protection as an opportunity to engage in the review and revision of the System. This digital workshop took place from 14 October–3 November 2021 and included 20 live-streamed and 43 on-demand presentations. Approximately 1500 individuals from 100 countries participated. Based on the subjects covered by the presentations, this summary is organized into four broad areas: the scientific basis, concepts and application of the System; and the role of the ICRP. Some of the key topics that emerged included the following: classification of radiation-induced effects; adverse outcome pathway methodologies; better understanding of the dose–response relationship; holistic and reasonable approaches to optimization of protection; radiological protection of the environment; ethical basis of the System; clarity, consistency and communication of the System; application of the System in medicine and application of the principles of justification and optimization of protection.
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