Onoe M, Fukuba N, Kodama Y
… +7 more, Kotani S, Oka A, Oshima N, Shibagaki K, Kawashima K, Ishimura N, Ishihara S
Radiat Prot Dosimetry
· 2025 Oct · PMID 40971554
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BACKGROUND AND AIMS: Healthcare professionals involved in fluoroscopy-guided endoscopy are occupationally exposed to ionizing radiation. We evaluated whether a patient-immobilization device, MEDO V-Fix®, reduces this exp...BACKGROUND AND AIMS: Healthcare professionals involved in fluoroscopy-guided endoscopy are occupationally exposed to ionizing radiation. We evaluated whether a patient-immobilization device, MEDO V-Fix®, reduces this exposure. METHODS: Monthly effective and lens equivalent dose were measured for nurses and doctors using personal dosemeters worn inside protective gear. Data from 7 months before and 10 months after device introduction were compared. Additionally a cost-benefit analysis (CBA) of dose reduction was performed. RESULTS: Monthly effective doses fell in both professions, but neither decline reached statistical significance. By contrast, nurses' mean lens-equivalent dose dropped sharply from 35.0 to 6.5 μSv per procedure (P < 0.01), whereas the reduction in doctors was not significant. In the CBA, assuming a 5-y service life, the benefit-to-cost ratio ranged 1.02-2.72, indicating economic merit. CONCLUSIONS: The MEDO V-Fix significantly reduces the occupational radiation exposure of endoscopy nurses and is a worthwhile investment from a CBA perspective.
The dicentric chromosome assay serves as the "gold standard" for biodosimetry, playing a crucial role in rapid clinical decision-making during extensive nuclear radiation incidents. This study aimed to develop a semi-aut...The dicentric chromosome assay serves as the "gold standard" for biodosimetry, playing a crucial role in rapid clinical decision-making during extensive nuclear radiation incidents. This study aimed to develop a semi-automated dose-response curve for the analysis of dicentric chromosomes induced by irradiation of human peripheral blood lymphocytes with 60Co gamma rays. Blood samples were collected from three healthy donors and subjected to irradiation, culture, and harvesting, following International Atomic Energy Agency standard protocols. The Metafer4 system, an automatic scoring system, was utilized to acquire images of the metaphase chromosome segregation phase, and the dose-response curve was constructed through automatic analysis of dicentric chromosomes supplemented by manual verification. The curve was subsequently validated through blind scoring. The results demonstrated that the semi-automated scoring method provides quick and precise dose estimations and offers a viable alternative to manual dicentric chromosome assay. This approach holds significant potential for application in the nuclear emergency management of large-scale radiological events.
The High-Intensity Proton Accelerator Facility at the Paul Scherrer Institute (PSI) accelerates protons to an energy of 590 MeV with currents up to 2.4 mA, i.e. 1.4 MW beam power. The beam feeds four main experiments usi...The High-Intensity Proton Accelerator Facility at the Paul Scherrer Institute (PSI) accelerates protons to an energy of 590 MeV with currents up to 2.4 mA, i.e. 1.4 MW beam power. The beam feeds four main experiments using individual targets. The areas adjacent to these targets are heavily shielded by several meters of iron and concrete. The neutron stray field at different positions outside the shielding close to two of these targets has been investigated using the PSI extended range Bonner sphere spectrometer (ERBSS). It consists of 10 moderator spheres made of polyethylene and 4 spheres modified with metal shells, enhancing the sensitivity for neutrons with energies >20 MeV. The data was normalized to the proton current measured by a resonance chamber upstream of the first target. Two commercially available survey instruments for neutron radiation constantly monitored the stability of the field during the measurements. The spectral neutron distribution was determined by applying Bayesian methods, which were optimized for measurements of neutron stray fields behind shielding at high-energy accelerators. The measurements within restricted access areas resulted in ambient dose equivalent rates of 25-50 μSv (h mA)-1 with significant contributions of high-energy neutrons. The comparison to doses indicated by a commercially available survey instrument suitable for measurements in fields with a high-energy neutron component showed reasonable agreement with the dose values obtained from the ERBSS measurement. However, it is desirable to apply in-field calibration factors derived from spectrum measurements to reduce the uncertainty of dose values obtained with survey instruments.
In radiological imaging, much research has been conducted on tube voltage and additional filters to reduce radiation exposure. In this study, the usefulness of heavy metal filters in lumbar spine imaging to maintain imag...In radiological imaging, much research has been conducted on tube voltage and additional filters to reduce radiation exposure. In this study, the usefulness of heavy metal filters in lumbar spine imaging to maintain image quality and reduce radiation dose was investigated. A human-body phantom was irradiated with various combinations of tube voltages (70, 75, 80, 85, and 90 kV) and filters (Cu, Gd, Ho, Yb, W). For all beam qualities, the mAs value was adjusted so that the amount of CsI fluorescence at each dose after passing through the phantom was the same, and the contrast-to-noise ratio (CNR) and entrance-surface air dose (ESD) were measured. At 80 kV-Gd, the ESD was reduced by 34% while maintaining the CNR. The results showed that 80 kV-Gd gave the optimal beam quality for anterior-posterior lumbar spine imaging of patients with a standard body type.
In recent years, academia has sought the therapeutic applicability of periodic low-intensity electromagnetic field exposure (< 1 h/d) for biomedical applications. We have designed and developed a monoaxial Helmholtz coil...In recent years, academia has sought the therapeutic applicability of periodic low-intensity electromagnetic field exposure (< 1 h/d) for biomedical applications. We have designed and developed a monoaxial Helmholtz coil chamber for non-invasive magnetic field exposure for therapeutic application, i.e. cancer therapy. In the current study, we observed 50 Hz extremely low-frequency pulsed electromagnetic field ELF-PEMF (1-3 mT) exposure effects on cell proliferation and morphology of cancer cell lines under in vitro conditions. We witnessed significant changes in cell proliferation and morphology of A549 cells for exposure durations of < 1 h/d. We also noticed a notable change in the actin cytoskeleton and shrinking of cell nuclei in A549 cells compared to the control groups. However, HepG2 and MCF-7 cells were notably unaffected by the current experimental conditions. The experimental evidence indicated that 50 Hz ELF-PEMF exposure of less than 1 h/d can significantly alter cell proliferation and induce morphological changes in A549 cells. This innovative, targeted, non-invasive method can be a popular therapeutic choice for patients with advanced stages of cancer. Moreover, exposure protocols will be much more helpful for clinicians depending on the patient's conditions, type of cancer cells, and exposure conditions, i.e. field intensities and duration.
Herzner V, Katzlberger C, Pfeifer C
… +2 more, Maringer FJ, Weigl-Kuska M
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875280
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This study assessed the radiological risk of wood fuels and their ashes in Austria, including wood chips, logs, pellets, and briquettes. Commercially purchased wood fuels are often of unknown origin and may have been imp...This study assessed the radiological risk of wood fuels and their ashes in Austria, including wood chips, logs, pellets, and briquettes. Commercially purchased wood fuels are often of unknown origin and may have been imported. 137Cs activity concentrations were measured in wood fuels (69 samples) and their ashes (27 samples) using gamma-ray spectrometers with high-purity germanium detectors. 90Sr analyses were performed on 12 ash samples after chemical separation using PerkinElmer 1220 Quantulus™ liquid scintillation counters. Results showed 137Cs activity concentrations ranging from 0.327 to 8.36 Bq kg-1 in wood fuels (average 2.1 Bq kg-1) and from 11.80 to 867 Bq kg-1 in ashes (average 310 Bq kg-1). The 90Sr activity concentrations in ashes ranged from 363 to 1200 Bq kg-1 (average 655 Bq kg-1). Summarizing, this study suggests that wood fuels currently available in Austria do not pose a significant radiological risk from their ashes, negating the need for import regulations.
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875279
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Carbon-14 often dominates the effective dose to the public from authorized discharges from Swedish nuclear power plants (NPPs). In contrast to air-borne releases, water-borne discharges of 14C are currently not routinely...Carbon-14 often dominates the effective dose to the public from authorized discharges from Swedish nuclear power plants (NPPs). In contrast to air-borne releases, water-borne discharges of 14C are currently not routinely monitored at Swedish NPPs. We have measured 14C in Fucus spp. (brown algae, used as bioindicators of 14C) in shallow waters at the Swedish west coast from 2020 to 2024. At Ringhals NPP, 14C in Fucus spp. was up to ~50 per cent higher than at nearby marine reference sites and was also higher than observed in the nearby terrestrial environment. The local marine environment of Ringhals NPP showed high spatial and temporal variability in 14C. Carbon-14 in Fucus spp. was generally higher in Skagerrak than in the more southernly Kattegat, likely mainly due to influence from discharges from the spent nuclear fuel reprocessing plant in La Hague in France and from its counterpart in Sellafield in the UK.
Wålinder R, Isaksson M, Rääf C
… +1 more, Tondel M
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875278
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Thyroid dose estimations after nuclear power plant (NPP) accidents are traditionally based on internal uptake of radioiodine, mainly 131I, either by instrumental measurements of thyroid uptake or by ecological estimation...Thyroid dose estimations after nuclear power plant (NPP) accidents are traditionally based on internal uptake of radioiodine, mainly 131I, either by instrumental measurements of thyroid uptake or by ecological estimations based on geographical dispersion of the radioiodine cloud, demographics, and food habits. However, it has been shown that 134Cs and 137Cs in some cases can be the dominant contributors to the thyroid dose over long time following NPP accidents. Based on an ecological model using Swedish-specific parameters of the radioactive fallout from the Chernobyl accident in 1986, estimations of the protracted (30 years) thyroid absorbed dose were made for the population in northern Sweden (2.2 million inhabitants in 1986). The internal dose contribution was estimated from both the short-lived nuclides-mainly 131I (T½,phys = 8.1 d) in dairy milk and from inhalation-and nuclides with longer half-lives-134Cs (T½,phys = 2.06 y) and 137Cs from aggregate ecological transfer of radiocesium in foodstuff (T½,phys = 30.2 y). The external radiation dose to the thyroid was based on air-borne measurements of the ground deposition of 137Cs, combined with absorbed dose contribution of short-lived radionuclides and with correction for shielding from residential buildings and snow cover. The total thyroid absorbed dose from 1986 to 2015 ranged from 0.06 to 15.5 mGy (mean 2.0 mGy) among subjects in the study population. The calculated mean thyroid absorbed dose the first year was 0.7 mGy, where radioiodine accounted for ~0.3 mGy. The protracted thyroid absorbed dose after 30 years was 0.3 mGy (15%) from 131I, and 1.7 mGy (85%) from internal and external 134Cs and 137Cs taken together. Hence, the estimated mean absorbed dose contribution from radiocesium was higher than for radioiodine (131I) both in the first year and in the consecutive 30 years. Furthermore, the 30-year external absorbed dose (1.2 mGy) dominates over the internal absorbed dose (0.8 mGy) to the thyroid. This finding is of relevance for low-dose exposure epidemiological studies of thyroid cancer which previously have focused solely on radioiodine.
Rääf C, Frost R, Bernhardsson C
… +1 more, Pédehontaa-Hiaa G
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875277
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The Swedish Radiation Safety Authority has presented a report on severe accident scenarios at the European Spallation Source (ESS) for dimensioning the emergency preparedness zones around the facility. The source-term in...The Swedish Radiation Safety Authority has presented a report on severe accident scenarios at the European Spallation Source (ESS) for dimensioning the emergency preparedness zones around the facility. The source-term in the scenario consisted of more than 80 tungsten-target spallation products with physical half-life (T½) exceeding 1 hour. The purpose of this study is to establish which of these radionuclides will become of highest importance in terms of the radiological consequences to residents in areas affected by an accident release. In analogy with accidents at nuclear power plants, where the fission product 137Cs is a key nuclide for estimating projected external doses to affected residents, a corresponding key nuclide for ESS is required for the emergency preparedness. Using existing accident source terms in combination with reported values on ecological half-times of the gamma emitter 137Cs, the external dose rates and cumulative doses per unit initial ground deposition of the suggested key-nuclide (182Ta) could be estimated. In terms of 50 y dose from a dry deposition of the released source-term, 172Lu (T½ = 6.7 d, supported by 172Hf with T½ = 1.87 y) contributes up to 50% of the 50 y dose, depending on the ecological half-times for the element. The isomer 178nHf (T½ = 31 y) is the second largest contributor to gamma-ray dose, followed by 182Ta (T½ = 115 d), that contribute with about 15% and 10% of the 50 y dose, respectively. The results thus suggest that 172Hf/172Lu may be more suitable for long-term follow-up of projected doses from accidental ESS releases than 182Ta.
Deyhle RT, Bernhardsson C, Olsson LE
… +1 more, Sydoff M
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875276
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In vivo preclinical X-ray micro-computed tomography (μCT) imaging is widely used to obtain three-dimensional anatomical information of small animals. However, the potential for radiation exposure to influence experimenta...In vivo preclinical X-ray micro-computed tomography (μCT) imaging is widely used to obtain three-dimensional anatomical information of small animals. However, the potential for radiation exposure to influence experimental outcomes necessitates accurate dose estimation. The aim of this study was to develop a robust and reproducible method for estimating and evaluating absorbed doses in small animals undergoing preclinical in vivo μCT imaging. Absorbed doses were measured at four separate positions within a dedicated polymethyl methacrylate phantom using MCP-N (LiF, Cu, P) thermoluminescence dosemeters (TLDs) and a novel type of optically stimulated luminescence dosemeter (OSLD) made from household salt (NaCl). The findings were benchmarked against the vendor's absorbed dose estimates, revealing a discrepancy between the measured and provided values. The results for the OSLDs followed a similar trend to the TLDs, though significant statistical differences were found between the luminescent dosemeters and the vendor values. In this study, a method for measuring the absorbed doses from μCT systems was presented. The results indicate a need for thorough dose measurements prior to performing longitudinal imaging studies.
Rassol N, Ytterbrink C, Pettersson D
… +5 more, Al-Awar A, Bakr H, Gram M, Spetz J, Forssell-Aronsson E
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875274
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Late radiation-induced kidney toxicity limits molecular radionuclide therapy using radiopharmaceuticals such as 177Lu-octreotate and 177Lu-octreotide. Better kidney protection would allow higher amounts of radiopharmaceu...Late radiation-induced kidney toxicity limits molecular radionuclide therapy using radiopharmaceuticals such as 177Lu-octreotate and 177Lu-octreotide. Better kidney protection would allow higher amounts of radiopharmaceutical to be administered. Coadministration of recombinant human alpha-1-microglobulin (rA1M) has been suggested to protect kidneys from exposure from 177Lu-octreotate. Furthermore, early responding biomarkers are needed that identify patients that should or should not receive higher radiopharmaceutical activity. The aim of this study was to evaluate effects of different administration schedules of rA1M in combination with 177Lu-octreotide on urinary levels of retinol-binding protein 4 (RBP4) and creatinine (Cr). Mice received 60 MBq 177Lu-octreotide intravenously, plus none, one, or several rA1M injections. Urinary RBP4 and Cr concentrations were measured after 6-10 weeks. Urinary RBP4 was similar in all groups, but with large individual variations in some groups. RBP4/Cr may be a useful early-responding biomarker. Further investigations are needed to determine effects of long-term kidney protection by rA1M schedules.
Andersson M, Leggett R, Eckerman K
… +1 more, Mattsson S
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875273
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Internal dosimetry of diagnostic nuclear medicine requires biokinetic and anatomical models to estimate the radiation exposure from a radiopharmaceutical. Biokinetic models predict the uptake, turnover, and retention of...Internal dosimetry of diagnostic nuclear medicine requires biokinetic and anatomical models to estimate the radiation exposure from a radiopharmaceutical. Biokinetic models predict the uptake, turnover, and retention of the radionuclide in organs and tissues, while anatomical models estimate energy absorption from decay using computational phantoms. To make more accurate predictions of biokinetic transfer, the International Commission on Radiological Protection (ICRP) has introduced a new compartmental framework, based on a systemic blood model, which can be used to estimate the transfer of the administered radionuclides between organs and tissues. The ICRP Task Group 36 (TG-36) is developing the biokinetic models and dosimetric calculations for radiopharmaceuticals for the ICRP. IDAC-BioDose integrates compartmental modeling and IDAC-Dose2.2. For the biokinetic predictions, transfer rates are generated through empirical data by curve fitting. IDAC-BioDose is benchmarked with SAAMII and DCAL and is used by ICRP TG-36 to revise the biokinetics and dosimetry for ICRP Publ. 128. This comprehensive software expedites absorbed dose and effective dose assessments in the field of diagnostic nuclear medicine.
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875272
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High energy prices recently have moved nuclear power back into the limelight. The biggest risk of nuclear industry has been large-scale accidents that give rise to ground deposition of long-lived fission products such as...High energy prices recently have moved nuclear power back into the limelight. The biggest risk of nuclear industry has been large-scale accidents that give rise to ground deposition of long-lived fission products such as 137Cs, notably Chernobyl in 1986 (Ukraine) and Fukushima in 2011 (Japan). In Japan, extensive land remediation of residential areas was carried out at an estimated direct cost between 16 and 41 billion Euros. We have studied a hypothetical radioactive fallout scenario in Sweden and then applied a cost-benefit analysis on remediation of urban land and resettlement of evacuees. Direct costs for remediation of amounts to ⁓100 million Euro/km2 (2020 price levels). For an average city in Sweden the costs related to evacuation and decontamination greatly exceed the potential monetary benefits from averting radiation induced cancers. Thus, based solely on financial factors, it is concluded that an exhaustive evacuation and resettlement is not monetary cost-effective.
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875271
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The Nordic Society for Radiation Protection (NSFS) was founded in 1964 at the initiative of Rolf Sievert. Its task is to activate the exchange of knowledge and experience in the Nordic countries regarding protection agai...The Nordic Society for Radiation Protection (NSFS) was founded in 1964 at the initiative of Rolf Sievert. Its task is to activate the exchange of knowledge and experience in the Nordic countries regarding protection against ionizing and non-ionizing radiation, for all kinds of occupational, medical, or public exposures. NSFS has always included members from all five Nordic countries and was a founding member of IRPA, the International Radiation Protection Association. Since 1966, NSFS has had regular meetings at 3- or 4-year intervals, in turn in each of the Nordic countries. In addition, NSFS has arranged various themed meetings. The meetings of the Society have been informal and collaborative and important for transfer of skills between generations. The activities have stimulated Nordic co-operation regarding nuclear safety research, nuclear waste, radioecology, medical radiology, and clinical physics, as well as Nordic postgraduate courses. NSFS lives up to the IRPA motto of being the international voice of the RP profession.
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875270
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A field survey was conducted in Sweden with the purpose to revisit the ground deposition of Chornobyl 137Cs and the associated ambient dose equivalent rate, H* (10), at various measuring locations in the Gävle and Älvkar...A field survey was conducted in Sweden with the purpose to revisit the ground deposition of Chornobyl 137Cs and the associated ambient dose equivalent rate, H* (10), at various measuring locations in the Gävle and Älvkarleby municipalities. The specific purpose was to compare the 137Cs deposition values as measured in situ using a field portable gamma spectrometer [3″(Ø) × 3″ NaI(Tl)-crystal] with the ex situ estimates obtained from gamma spectrometry of soil cores taken at the measuring locations. An additional purpose was to re-assess the effective ecological half-times of the Cs-contribution to the H* (10) and compare with a previous assessment done for data until 2013. The results show that ex-situ soil sample data exceed the 137Cs deposition values from the field portable NaI(Tl) gamma spectrometer by, on average, 50%. The discrepancy could mainly attributed to the difference between the actual field-of-view seen by the portable device at 1 m above ground compared with the calibration geometry of an infinite planar surface with a Cs ground penetration at 3 g cm-2. The H* (10) measurements collected in 2022 could indicate that the effective ecological half-time of 137Cs attributed ambient dose equivalent rate in the area ranges between 10 and 20 y instead of the 6.8 y obtained from the previous assessment of data between 1987 and 2013. The findings demonstrate, however, the usability of the portable field gamma spectrometer when used to characterize the long-term time dynamics of external doses from 137Cs in cases where the 137Cs dose contribution is well below normal background levels.
Mattsson S, Stenström KE, Pédehontaa-Hiaa G
… +5 more, Bernhardsson C, Jönsson M, López-Gutiérrez JM, Lérida-Toro V, Calvo EC
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875269
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Samples of Fucus serratus and Fucus vesiculosus have been regularly collected at Särdal (56.76 N, 12.63E) on the Swedish west coast since 1967, for most of the time, every two months. In 2020, sampling of Fucus spp. was...Samples of Fucus serratus and Fucus vesiculosus have been regularly collected at Särdal (56.76 N, 12.63E) on the Swedish west coast since 1967, for most of the time, every two months. In 2020, sampling of Fucus spp. was extended to 44 other locations along the Swedish west, south, and east coast for comparison with Särdal data. At seven of these locations, water samples and extra samples of Fucus spp. were also taken for 3H analysis. Measurements have been performed by gamma spectrometry, or by radiochemical separation followed by low background beta measurements, alpha spectrometry or accelerator mass spectrometry. Time variations of the measured concentrations of various radionuclides (3H, 14C, 60Co, 99Tc, 129I, 131I, 134Cs, 137Cs, 236U, 238U, 239Pu, and 240Pu) are reported. The concentrations have been correlated with emissions from the nuclear fuel reprocessing facilities at Sellafield (UK) and La Hague (France). Contributions from the nuclear power plants in Ringhals and Barsebäck have also been identified, as has fallout from Chernobyl still stored mainly in the sediments and water of the Baltic Sea. In recent decades, studies have shown increasing levels of 129I and 236U and decreases in 137Cs, 99Tc, and 239 + 240Pu concentrations over time. The 14C analyses show an impact of anthropogenic 14C from activities other than atmospheric nuclear weapons tests in the 1950s and 1960s. The considerable variation in the concentration of different radionuclides over time and along the coasts warrants further studies to determine the possible origin of these radionuclides and to map background data in the event of future releases.
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875268
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A mobile gamma spectrometer's series of pulse height distributions (gamma spectra) acquired when passing a point source contains enough information to derive the distance to the source, its shielding and activity. Two Ex...A mobile gamma spectrometer's series of pulse height distributions (gamma spectra) acquired when passing a point source contains enough information to derive the distance to the source, its shielding and activity. Two Excel routines, SODAC and SSC, have been developed to determine these source parameters. SODAC determines the source-road distance by finding the best fit of the measured series of the primary photon peak count rates to a count rate function characteristic of the distance to the source. A possible source shield reduces the primary count rate and raises the count rate from Compton scattered photons in the shield. SSC calculates the shield mass thickness for common building material using ratio functions of scattered to primary count rates obtained from measurements on known shielding geometries. SODAC then calculates the source activity. The technique was practically tested for 137Cs point sources but can also be applied to other gamma-emitting radionuclides.
Björk KI, Langen B, Schroff A
… +4 more, Shubbar E, Helou K, Spetz J, Forssell-Aronsson E
Radiat Prot Dosimetry
· 2025 Aug · PMID 40875266
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131I is recognised, both for its significance in nuclear medicine, and for its association with a rise in paediatric but not adult thyroid cancer cases following the Chornobyl accident. However, the detailed radiobiologi...131I is recognised, both for its significance in nuclear medicine, and for its association with a rise in paediatric but not adult thyroid cancer cases following the Chornobyl accident. However, the detailed radiobiological mechanisms underlying 131I effects on the thyroid remain unknown to date. In the present study, 1 kBq or 100 kBq 131I was administered to mice that were euthanised after 48 h, 3 weeks or 6 months. Thyroid glands were surgically removed, and proteins were extracted and analysed by tandem mass spectrometry. On a group-level, the results showed few alterations in protein abundance, mainly linked to RNA metabolism and DNA damage response. However, individual analysis of protein abundance changes in each animal showed distinct findings suggesting inhibited proliferation in a few individuals across various exposure levels and time points. Future studies should involve larger animal groups to better assess the frequency and variability of proteomic radiation responses.