Health physics最新文献

Introduction: As a new research technology, pulsed high magnetic fields (PHMF) have been gradually used in many fields such as industry, communication, and medical treatment. However, there is still a lack of studies on the safety of PHMF and their effects on autoimmune inflammation. Our work aims to expand the possibilities of PHMF application in autoimmune disease therapy and provide a foundation for further refined research into the safety of PHMF.

Materials and methods: We used 30 DBA/1J mice to investigate the effects of 7.25 T PHMF exposure for 10 days on normal mice and collagen-induced arthritis (CIA) mice, a kind of autoimmune inflammation model.

Results: White blood cell counts, neutrophil counts, eosinophil counts, basophil counts, neutrophil percentage, the variable coefficient of red blood cell distribution width, and the standard deviation of red blood cell distribution width of normal mice were significantly up-regulated and lymphocyte percentage was significantly down-regulated by twice-daily 7.25 T PHMF. The body weight, other blood routine indexes, and organ pathological manifestations were not significantly affected by the PHMF. Moreover, different doses of PHMF exposure did not have significant effects on body weight, arthritis score, joint pathology, synovitis score, and the expression of inflammatory cytokines in CIA mice.

Conclusion: In general, daily short-term exposure to 7.25 T PHMF does not have severe effects on normal mice and CIA model mice, and more studies are needed to verify its safety and efficacy.

Strontium is a ubiquitous element due to its presence, of both natural and anthropogenic origin, in all environmental compartments. In stable or radioactive form, it has numerous industrial and medical applications and is also used in research projects. For radioactive isotopes of strontium, the risk of exposure through irradiation or internal contamination is therefore very real. In addition, in the current international context, CBRN (chemical, biological, radiological, nuclear) risks have increased and diversified, with a more present terrorist component. Among the possible scenarios, malevolent acts such as the use of a "dirty bomb" containing sources of radionuclides (including strontium) currently used in industry, in the medical field, or for research must be envisaged. As a result, the authorities need to have effective and operational tools of prevention and protection at their disposal to be able to respond to these growing threats, which expose not only the civilian population but also the military and first responders. This review presents the most relevant up-to-date data, notably covering biokinetics, health effects, and pharmacological treatments following internal contamination exposure to radioactive strontium compounds. Following this critical review of existing research work, the need for additional advanced knowledge is emphasized in the fields of toxicity and medical treatments, which are fundamental areas in radiation protection.

FLASH radiation therapy is a promising modality that delivers radiation at ultra-high dose rates, potentially minimizing normal tissue toxicity while maintaining tumor control. However, conventional dosimetry tools often fail at ultra-high dose rates, necessitating alternative solutions. Alanine dosimetry, a passive technique known for its dose-rate independence and tissue equivalence, presents a compelling option. While other studies have used alanine pellets, this study investigates the applicability of alanine powder dosimeters in FLASH radiation therapy. Thirteen dosimeters were irradiated with doses from 10 to 100 Gy using a 137Cs source. Six samples were used to construct dose-response calibration curves, while the remaining seven were used for validation. Peak-to-peak amplitudes of the electron paramagnetic resonance signal were normalized using internal standards and sample density. Dose estimates based on density-normalized calibration were within ±4.2% of expected values, demonstrating strong linearity (R2 > 0.99) and clinical viability. While post-processing time remains a limiting factor, this work affirms the potential of alanine powder as a reliable tool for FLASH dosimetry, especially for high-dose, dose-rate-independent measurements.

A comparison among three models (Birattari Conic Plume, HotSpot, and NCRP 123 Gaussian distribution) has been carried out concerning the release of air-activated radionuclides during bombardment of a H218O target in a medical cyclotron with two different proton energies: 10 MeV and 18 MeV. Under worst-case meteorological conditions, the diffusion of 13N, 40Cl, 37S, and 41Ar has been investigated. The total amount of induced activation (Bq) during different beam times has been calculated for each isotope, and the three models have been used to assess the dose to the residential population located 100 m from the release point, for a fixed beam current of 100 µA. The results demonstrate that a facility for medical isotope production, even under heavy workload (3,000 µA h-1 wk-1), will not lead to a significant increase in the dose to the surrounding population.

Effective radiation monitoring is crucial for ensuring public security and safety, particularly in the event of nuclear (e.g., nuclear accident, fallout, etc.) or radiological (e.g., radiation source spill, dirty bombs, etc.) emergencies. Traditional monitoring methods often lack real-time capabilities and comprehensive data visualization and analysis, which can delay response time and increase further risks. To address this gap, this research proposes an Advanced Radiation Detector for real-time radiation monitoring. The novelty is in its use of an internet of things (IoT)-based framework to collect and transmit all the data (e.g., radiation level, temperature, pressure, humidity, and air quality) via a GSM module to web cloud all from one device with enhanced visualization in the self-made website. The study setup will obtain data across the area of the Military Institute of Science and Technology (MIST), Mirpur Cantonment, Dhaka, Bangladesh, using this Advanced Radiation Detector. This data is visualized by creating a scatter circle map of spatial distribution of radiation measurements. By visualizing radiation data taken from the self-developed detector and visualizing it using the self-made website, we found the Advanced Radiation Detector meets its objectives perfectly. This research aims to enable real-time radiation monitoring and provides timely insights for emergency responses. By integrating IoT in the system, it has directly overcome the limitation of traditional methods. The Advanced Radiation Detector has immense potential to improve security and safety measures. The current Rooppur Nuclear Power Plant (RNPP) development in Bangladesh emphasizes the necessity of customized solutions for efficient radiological risk management. In order to improve Bangladesh's nuclear safety framework, this study presents a revolutionary IoT-based radiation monitoring system that uses machine learning for real-time assessment and predictive analytics.

We analyzed the US Nuclear Regulatory Commission event notifications related to unplanned exposure to fetus or embryo for events that occurred between 1 January 2005 and 31 December 2024. A total of 39 events were identified, 28 related to therapeutic and 11 to diagnostic nuclear medicine; no events related to brachytherapy or gamma teletherapy were found. The number of events fell during the study period (2005-2009: 15; 2020-2024: 6). The radioisotope in most (71.8 %) of the events was 131I. A pregnancy test was performed in 21/28 therapy events and in 0/11 diagnostic events. The estimated age of the fetus ranged from 1 to 26 wk (mean 5.7 wk); in two therapy events, conception occurred after the administration of the radiopharmaceutical. The mean reported estimated dose to the fetus was 260 mSv (SD: 190; range 20-860) for the therapy events and 17 mSv (SD: 6; range 10-26) for the diagnostic events. Unplanned fetal exposures are occurring; for therapy events, the estimated dose to the fetus is often high enough that adverse effects are possible. We suggest institutions review their policies on patient consent and pregnancy testing.

Accurate neutron dose assessment in humans is critical for radiation protection and nuclear emergency medical rescue. This study aims to establish a reliable method for evaluating neutron doses using a newly developed voxel physical phantom and to determine the lower detection limit of neutron absorbed dose via 24Na activity measurement. A voxel physical phantom, based on the ICRP 110 male adult reference computational phantom, was constructed using tissue-equivalent materials and sodium carbonate solutions to simulate sodium content in various organs. The phantom was irradiated with 252Cf neutrons, and the induced 24Na activity was measured using a 3-inch NaI(Tl) detector. Monte Carlo simulations were employed to validate the neutron fluence and dose distribution within the phantom. The results showed that the whole-body neutron absorbed dose in the voxel physical phantom differed by less than 3.1% compared with the ICRP 110 male adult reference computational phantom, with induced 24Na activity deviations of less than 3.0% for the whole body and 20.0% for major tissues and organs. When using a 3-inch NaI(Tl) detector to evaluate the neutron absorbed dose of the ICRP 110 male adult reference computational phantom irradiated with 252Cf neutrons instantaneously by measuring the induced 24Na activity, the lower limit of neutron absorbed dose detection was ≤ 31 mGy. This demonstrates the accuracy of neutron dose assessment using computational phantoms, providing a practical and cost-effective alternative to conventional approaches.

The 1956 recommendation by the US National Academy of Sciences (NAS) Biological Effects of Atomic Radiation (BEAR) I Genetics Panel to transition from a threshold to a linear dose response model for hereditary effects had a profound impact on environmental/occupational risk assessment, affecting policies/practices of US regulatory agencies, having much influence on regulations worldwide to the present. The recommendation gained influence due to the authority of the NAS, the prestige of the Panel, and the claim of a striking degree of uniformity among six independent estimates of radiation-induced hereditary risk. This claim was orchestrated by panelist James Crow who removed conflicting findings from the nine panelists who submitted estimates, acting with the approval of the entire Panel. These misrepresentations were ensured by the US NAS President who refused to share the Panel's technical reports and related documents with the scientific community. Ironically, the mouse mutation rate data used by the panelists who calculated risk estimates for either mouse or Drosophila were incorrect due to falsification by panelist William Russell without their knowledge. This action led to greatly exaggerated mutation risks and enhanced their overall false impression of agreement/scientific convergence. The actions of Crow were such that the already grossly inflated and falsified risk estimates of the panelists were made to appear in reasonably good agreement. These massive and compounded errors and deceptions have significantly affected regulatory practices for cancer risk assessment in the US and globally to the present. The present paper provides for the first time in the scientific literature an assessment of the unpublished technical reports of each of the nine participating geneticists of the BEAR I Genetics Panel and provides the basis for the above critical conclusions.

Radiation-based medical techniques and devices provide significant benefits to patients through the diagnosis, treatment, and management of illness and disease. Documenting trends and frequency of use offer important insights into radiation protection and help address gaps in the documentation of medical exposures. Here, we present the retrospective Canadian data collected for the recent United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) global survey on medical exposure. The global survey included three modality categories: diagnostic and interventional radiology, nuclear medicine, and radiotherapy and reports the total number of devices, physicians, examinations, and procedures. Due to the inability to collect high-quality dose data from Canadian sources, the average doses for specific examinations and treatments were estimated using internationally pooled data. The total annual per capita dose from medical exposures was determined to be 1.56 mSv, excluding radiotherapy, resulting in approximately 47% of all radiation doses received by Canadians, compared to natural, industrial, and consumer product sources. This assessment of Canadian medical radiation exposures contributes to global improvement of patient protection, helps establish trends, and identifies where Canadian data collection is lacking, particularly dose data.

The accidental ingestion of radioactive iodine is known to increase the risk of thyroid cancer and thyroid dysfunction; hence, strict radiation safety measures are required when handling it. In a previous study, we demonstrated that absorbing radioactive-iodine-containing wastewater using a water-absorbent polymer with cyclic oligosaccharides that selectively capture iodine, followed by natural drying, effectively separates at least 80% of the iodine from the wastewater. However, because natural drying requires approximately 2 wk, faster processing is essential to improve the efficiency of this wastewater treatment. Hence, we propose a method for quickly separating iodine from wastewater via heat drying. This study aimed to compare radioactive iodine volatilization levels between samples subjected to heat-drying- and natural-drying-based iodine and water separation. Na 125 I was added to purified water and artificial urine to prepare simulated waste liquids containing iodine at concentrations equivalent to those in the urine of patients undergoing radioactive iodine treatment. The prepared simulated waste liquids were poured into containers containing a superabsorbent polymer, dried in a thermostatic dryer set at 100 °C for 9 h, and subsequently stored for 90 d. The iodine residual rate in the simulated waste liquids was determined by measuring 125 I radioactivity. At the end of the heat-drying process, the iodine residual rates in the simulated waste liquids prepared with purified water and artificial urine were 0.452 and 0.783, respectively. When absorbed in 1 g of superabsorbent polymer, the residual rates increased to 0.956 and 0.952, respectively. Over the following 82 d, the residual rates decreased by approximately 10%. Thus, by absorbing radioactive-iodine-containing wastewater into a highly water-absorbent polymer and then applying heat drying, iodine can be effectively separated from the wastewater while limiting its volatilization to less than 15%.