Journal of Radiological Protection最新文献

This study analysed Japan's implementation of a regulatory framework that enables limited, non-residential land use in areas where radiation levels remain too high for repopulation following a nuclear accident, focusing on a wind power project in Katsurao Village, Fukushima Prefecture. Although international initiatives have advanced protective actions for the emergency phase of radiological events, comparatively little guidance exists for the recovery phase, particularly regarding procedures for lifting evacuation orders in persistently high-dose areas. Japan's experience is unique: while evacuation orders have been lifted across multiple municipalities, some zones remain unsuitable for habitation, necessitating new policy approaches. To address this gap, Katsurao Village employed the framework to authorise land use in a 19.9 hectare district designated for wind power generation. A multi-stakeholder committee-comprising residents, experts, government authorities, and industry representatives-was established to evaluate dose-reduction measures, access protocols, environmental maintenance, and operational safeguards. The committee identified several unresolved issues, including the absence of standardised monitoring procedures, challenges in managing worker exposure, the need for clear demarcation and communication to prevent unauthorised entry, and mechanisms for transparent reporting in the event of abnormal findings. This case demonstrates both the feasibility and complexity of enabling controlled land use in high-dose areas, underscoring the importance of governance, technical standardisation, and sustained risk communication.

The Rocky Flats (RFs) Plant operated from 1951-1989 as part of the U.S. Department of Energy (DOE) nuclear complex. Its primary mission was weapons component fabrication, whereby workers were potentially exposed to radioactive and non-radioactive hazards. RF worker mortality was compared to the general population, and dose-response relationships between mortality and radiation organ doses were examined. RF workers first employed between 1951 and 1979 for ⩾30 d were identified (n= 9397). Vital status was determined using national and state death records up to 2017. Organ doses from external photons and neutrons irritation and internalised plutonium (Pu), americium (Am), and uranium (U) were modelled as cumulative lagged total doses per year. Beryllium exposure was evaluated as an effect modifier using data from the DOE Nationwide Beryllium Medical Program. Statistical analyses included standardised mortality ratios (SMRs), Cox proportional hazard models, and excess relative risk (ERR) models. Approximately 53.2% of workers were deceased by the end of the study. Nearly 90% were monitored for radiation exposure, with a mean weighted absorbed dose of 59.0 mGy for the lungs. Nearly 45% of workers had intakes of alpha-particle emitting radionuclides, and 46.7% were monitored for neutrons. Leading causes of death included ischemic heart disease (n= 999) and lung cancer (n= 361). The highest SMRs were observed for berylliosis (SMR: 176.9; 95% CI: 76.2, 348.7;n< 10) and asbestosis (SMR: 4.65; 95% CI: 2.23, 8.55;n= 10). Dose-response analyses showed no statistical increase in risk from low-dose radiation including lung cancer (ERR per 100 mGy: -0.02; 95% CI: -0.11, 0.08;n= 361) and Parkinson's disease (ERR per 100 mGy: 0.13; 95% CI: -0.26, 0.31;n= 57). Approximately 45% of workers were monitored for beryllium, with a weak non-significant indication of effect modification for lung cancer risk. The RF cohort showed no evidence of a statistically significant increase in mortality from occupational radiation exposure. However, this study was limited by low statistical power, which inhibits the ability to detect effects. Future pooling of Million Person Study (MPS) cohorts will provide further insights, particularly regarding Pu as a carcinogen.

Shelter-in-place (SIP) is recognised alongside evacuation as a primary protective action during nuclear emergencies in Japan. Following the Fukushima Daiichi Nuclear Power Plant accident, increasing recognition of evacuation-related health risks-particularly among hospitalised and institutionalised populations-has strengthened policy emphasis on SIP within the urgent protective action planning zone (UPZ). However, little attention has been paid to the practical implementation of SIP in medical institutions. Hospitals face distinctive operational challenges during SIP, including business continuity planning (BCP), radiation protection, staff mobilisation, internal zoning, and the operation of positive-pressure systems. Despite widespread installation of such systems, their operational feasibility during nuclear emergencies remains largely unexplored. This study reports Japan's first implementation-oriented effort to operationalize SIP within a hospital setting. Since fiscal year 2024, a nuclear disaster preparedness working group has been established at Japanese Red Cross Matsue Hospital, a designated disaster base hospital located within the UPZ of the Shimane Nuclear Power Plant. Through staged departmental reviews and multidisciplinary discussions involving hospital staff and external stakeholders, operational challenges were systematically identified and incorporated into the hospital's BCP. By addressing the gap between SIP policy and operational feasibility, this study provides practical evidence to support nuclear emergency preparedness in medical institutions within UPZs.

Personal exposure to magnetic fields emitted by electronic article surveillance (EAS) systems was systematically assessed based on measurements of a representative sample of 19 different EAS devices. This sample included the two major EAS technologies currently on the market: acoustomagnetic (AM) and radio frequency (RF) systems. In addition to these measurements, numerical computations of the current densities and electric field strengths induced in body tissues were carried out for one representative AM-EAS device and several body models (adult male, adult female, child female, and a hand model) and reasonably foreseeable worst-case exposure scenarios using a real-valued magneto quasi-static solver, based on the Scalar Potential Finite Element (SPFE) method. The obtained measurement and computational results were compared to the different sets of exposure limits defined by the International Commission for Non-Ionizing Radiation Protection (ICNIRP) in 1998 and 2010. Our results demonstrated that current RF-EAS technology, which typically operates in the 8.2 MHz frequency range, does not conflict with the exposure limits, even under adverse exposure conditions. However, AM-EAS systems, which typically operate at 58 kHz, may lead to induced current densities in the central nervous system and induced electric field strengths in the peripheral nervous systems of adults and children that exceed the basic restrictions for the general public (up to a factor of 22.5 for the adult female bending in front of the antenna) and even for occupational exposure (up to a factor of 4.5 for the same scenario) according to the ICNIRP 1998 and 2010 guidelines under reasonably foreseeable exposure conditions, which are not covered by the assessment procedures defined in the present version of the applicable standard IEC EN 62369-1. Therefore, radiation protection and market regulatory authorities should have a close look and check presently installed and future AM-EAS technology with respect to their compliance to exposure limits.

From 29th September to 2nd October 2025, European Radiation Protection Week was hosted in London by the UK Health Security Agency with Imperial College London's Department of Epidemiology and Biostatistics. The meeting brought together the platforms under the MEENAS umbrella (MELODI, EURADOS, EURAMED, NERIS, ALLIANCE, and SHARE) to deliver a diverse programme of presentations and posters spanning the breadth of radiation protection research. This paper provides a summary of the meeting.

The context of armed conflict situations presents unique challenges that can compromise the safety and well-being of both affected populations and responders in radiological and nuclear emergencies. The focus of the EU project RRADEW "Resilience to RADiological Events in Wartime" is to enhance nuclear Emergency Preparedness, Response and Recovery (EPR&R) systems by strengthening resilience to potential incidents in the context of war or armed conflict. The project is structured in five workpackages focusing on the development of war scenarios (WP1), identification of resilience dimensions and indicators (WP2 and 3), development of decision-support, training materials and recommendations targeting key stakeholders (WP4), and key ethical questions for radiological protection in the context of armed conflicts (WP5). Together, these efforts aim to provide actionable frameworks and recommendations to ensure the safety and well-being of both affected populations and responders in wartime radiological incidents.

Introduction: Occupational radiation exposure among medical staff remains a critical concern, underscoring the importance of effective radiation-protection education. This study aimed to develop and evaluate educational materials incorporating an augmented reality (AR) application to visualize scattered-radiation distributions during radiological procedures.

Methods: The educational program comprised a 20-item true/false quiz, a questionnaire based on the Attention, Relevance, Confidence, and Satisfaction (ARCS) motivational model, and open-ended questions assessing perceived strengths and weaknesses.

Results: Pre-and post-training quiz scores demonstrated an improvement of approximately 10% in the overall correct-response rate, indicating measurable gains in factual knowledge related to scattered radiation and radiation protection. ARCS scores reflected high levels of learner motivation, with mean ratings of 3.98 for Attention, 3.99 for Relevance, 4.06 for Confidence, and 4.08 for Satisfaction on a fivepoint scale. Free-text responses suggested that visualizing scattered radiation with AR facilitated a more concrete understanding of its spatial distribution and the effectiveness of protective measures. However, both ARCS feedback and open-ended comments indicated that the training content was dense and that the exercise workload was perceived as burdensome. Participants also reported usability challenges related to the application interface.

Conclusion: Overall, the findings suggest that the AR-based educational materials can enhance both learner motivation and conceptual understanding of radiation protection, although further refinement of scenario design and interface usability is required to optimize learning efficiency and user experience.

This study presents the first comprehensive spatial analysis of activity concentrations of naturally occurring radioactive material (NORM) and absorbed dose rates across Bangladesh. Utilising a database compiled from 56 published studies and 40 unpublished theses (1990-present), environmental sample data were mapped onto a systematic grid system comprising 2094 cells (8.05 km × 8.05 km) from which measured and unmeasured locations were revealed across the country. Ordinary Kriging interpolation was applied to visualize nationwide distributions. The analysis revealed significant spatial heterogeneity primarily driven by differences in geology, rock structures, and soil types. Activity concentrations of Ra-226, Th-232, and K-40 ranged from 0.01 to 647.5 Bq kg^-1, 0.2-1230.0 Bq kg^-1, and 0.04-2352.0 Bq kg^-1, respectively. Consequently, the absorbed dose rates varied widely from 0.02 to 745.86 nGy h^-1, yielding a national average of 64.16 nGy h^-1. Furthermore, the gridded mapping exposed severe sampling imbalances: while some localized regions were measured up to 13 times, vast areas remain entirely unsampled. By establishing this pre-operational national baseline, this study successfully distinguishes natural background levels from potential technologically enhanced NORM. The findings provide a critical reference for ongoing environmental monitoring particularly to assess radiation levels around the soon-to-be-operational Rooppur nuclear power plant and offer a strategic framework to guide future targeted sampling in unmeasured regions.

Ionizing radiation elicits complex cellular responses that are influenced not only by total dose but also by the rate at which the dose is delivered. Understanding how dose rate modulates molecular outcomes is important for accurate risk assessment. In this study, we apply an integrative multi-omics approach combining transcriptomic and proteomic profiling while adjusting for covariates to investigate how differential dose rates of ionizing radiation alter gene and protein expression in human lymphocytes. Particular emphasis is placed on identifying dose-rate-specific alterations in key molecular pathways. Peripheral blood from 14 healthy donors (8 males, 6 females) was irradiatedex vivowith x-rays at 0.05 Gy min^-1(DR1) and 1.0 Gy min^-1(DR2) across a dose range from 0 to 6 Gy. Gene expression was assessed using TempO-Seq™, and relative protein abundance was determined by mass spectrometry. Differential expression analysis was conducted using edgeR and limma, adjusting for sex, age, and leukocyte counts (false discovery rate < 0.05). Multi-omics integration was performed using regularised canonical correlation analysis (rCCA) implemented in mixOmics, followed by Reactome pathway enrichment analysis. We identified 2477 and 2612 differentially expressed genes at DR1 and DR2, respectively, and 368 and 386 differentially expressed proteins. To assess dose discrimination, we examined sample separation in the space defined by the average canonical variates from transcriptomic and proteomic datasets using rCCA. Covariate adjustment improved dose discrimination, particularly above 0.5 Gy. Using a correlation cut-off threshold of 0.5 in rCCA, 212 (DR1) and 276 (DR2) highly correlated gene-protein pairs were identified. DR2 exposure was associated with stronger enrichment of stress-related pathways, including unfolded protein response, senescence and oncogenic kinase signalling. In contrast, DR1 induced enrichment of pathways associated with immune engagement, including antigen presentation. At both dose rates, transcriptomic changes highlighted upstream regulatory processes (chromatin modelling) and proteomic changes captured downstream functional pathways such as immune activity and apoptosis. The multi-omics approach with covariate adjustment revealed key radiation-responsive pathways and dose-rate-dependent molecular differences, highlighting the value of integrating transcriptomic and proteomic data to better understand radiation effects.