Health physics最新文献

A commentary written by Jan Beyea claimed that the HPS interview of Edward Calabrese on the historical evolution of the linear no-threshold model was unreliable because it overlooked key historical text and statistical concepts. Beyea states that the purpose of his commentary was to defend the integrity of historical figures and committees from the accusation of scientific misconduct as presented by Calabrese. Based on his review of the video series and other documents, he provided what he defined as evidence of errors of fact, reasoning, and statistics to support his position. If true, Beyea's work would have the effect of impugning the reputation of Calabrese, myself, and the credibility of the HPS. This response intends to expose the issues with Beyea's commentary, including mischaracterization of Calabrese's work, lack of objectivity, misleading and factually incorrect statements, reliance on secondary sources, ignoring evidence specifically provided in the video series, and failing to address evidence provided in primary-sourced documents that contradict his conclusions. As a result, the reliability of Beyea's commentary is highly compromised, representing a serious lack of scholarship, research, and objectivity such that it should be retracted by Health Physics Journal based on the Committee on Publication Ethics guidelines. The HPS interview-style documentary reflects historical events based on primary-sourced documents as discovered by Calabrese. Scientific debate on this topic is necessary to progress our field, but the debate must be supported by facts with primary-sourced evidence and not driven by outdated public policies, logical fallacies, or ideology.

Fluoroscopic C-arm units are used routinely in surgical procedures, but they pose potential radiation hazards, particularly in terms of scatter and tertiary exposure to healthcare providers, which can lead to long-term health effects. This study investigates the level of scatter radiation emitted by the C-arm during Dynamic Hip Screw (DHS) surgery across four general hospitals. A water phantom was placed in the center of the operating table, simulating an average patient. OSL dosimeters were placed at standardized distances and heights around all sides of the phantom to measure scatter radiation exposure. The OSL dosimeter readings recorded consistent scatter radiation levels for all positions (A, B, C, D, and E) and heights (0.5 m, 1.0 m, and 2.0 m). Exposure levels ranged from 0.06 to 0.09 mSv, with negligible variations based on distance from the phantom. One-way ANOVA results showed differences in scatter radiation exposure between hospitals (F-statistic = 2.68, p = 0.044). Despite inter-hospital variations, exposure levels were below international safety levels. Results indicate that healthcare workers are unlikely to surpass the yearly dose levels of radiation during normal use. Routine exposure highlights the necessity for proper safety precautions, such as lead aprons, shielding barriers, and room layout optimization. Future studies should take C-arm shielding and positioning into account to continue reducing exposure to scatter radiation. Further research is recommended to evaluate long-term cumulative exposure and improve radiation safety protocols.

A wide range of particle species, including neutrons, electrons, and photons, will be generated in a terawatt-level (TW) high-power laser facility, which poses considerable challenges for the development of effective radiation shielding solutions. The safety of both facility personnel and the public requires specified design considerations for these shielding systems. The Monte-Carlo code JMCT was employed to simulate and design the shielding structure for the TW facility. We calculated the radiation dose distribution throughout the entire facility for both single-shot and multi-shot operational modes. Our findings indicate that the strategic use of locally thickened shielding walls and mobile shielding measures can effectively mitigate radiation risks in TW-level laser facilities, ensuring that radiation doses within the personnel working area remain within regulatory limits. The results demonstrate that with these shielding strategies in place, the occupational exposure dose in the control room and the clean room can be confined to below 3 mSv y -1 , while the public dose remains below 0.1 mSv y -1 , considering an experimental frequency of 5 × 10 6 shots per year for overdense plasma experiments and 1 × 10 4 shots per year for underdense plasma experiments. The radiation shielding design method and results presented in this paper can serve as a reference for similar devices.

The linear no-threshold hypothesis (commonly known as LNT) has received increasing criticism in recent years. LNT assumes that the damaging effects of ionizing radiation, that is, stochastic effects such as cancer and genetic or teratogenic effects, increase linearly with dose and without a lower dose threshold. However, statistically verified data on the relationship between radiation and effects are only obtained for the range above 100 mSv y -1 , which is why linear extrapolation downward is carried out for the range of low radiation doses, i.e., below 100 mSv y -1 . Today's radiation protection systems are based on this principle. To place radiation protection on a different basis (that is, no longer on the LNT hypothesis), a traffic light model is proposed. It uses natural radiation exposure as a reference but maintains the existing limits and everything in radiation protection that has proven effective. What does change, however, is the lower end of the optimization range, according to the ALARA recommendation. For the justification of today's levels of exceptions, the precautionary principle is applied.

To improve monitoring capabilities, China CDC organized individual monitoring intercomparisons, which provincial health institutions participated in from 2022 to 2024. The irradiation schemes and evaluation criteria were designed in accordance with GBZ 207-2016, "Testing criteria of personnel dosimetry performance for external exposure." The Type II (photon) test specified in the standard was selected as the intercomparison type, with Hp (10) as the target quantity. Each institution submitted 21 dosimeters for participation in the intercomparison exercises. Irradiation schemes with various radiation quality and incident angles were randomly assigned to each participant. Out of 580 P i values, 82.6% (479) were classified as excellent, and 96.9% (562) met the qualification criteria. Four institutions reported 18 unqualified P i values. These demonstrate the reliable performance of the dosimetry systems. These intercomparisons helped participants identify system deviations and enabled radiation health administrative departments to grasp the capabilities of each institution, thus strengthening the protection of the occupational health of radiological workers.

Commercial businesses have long known that the image of an organization is critical to ultimate success. Significant resources are invested in marketing, logos, colors, signage, appearance, informational brochures, and the like because expenditures on these aspects have repeatedly proven to produce a measurable return on investment. The term "image" can be defined in many ways, but within the context of the effort described here, it is a tangible or visible representation of an entity. A radiation safety program's image can be based on many operational outcome elements, such as personnel doses, findings from regulatory compliance inspections, and measured client satisfaction. Described here are three other program image components that may be considered: the radiation safety program's website, program staff appearance, and program organizational charts. Data regarding the prevalence of current practices being carried out within operational college and university safety programs as they relate to image were measured via a series of simple online polls. Although the assessments described here were focused primarily on university environmental health and safety programs, each included specific consideration of any radiation safety component. The findings stemming from the analysis of these convenience sample polls examining the blind testing of program internet website search capabilities, the norms regarding program staff recognition on campus, and the common errors associated with organizational charts all can serve as a guide to improve radiation safety program image that, in turn, can maintain or enhance program reputation and support.

CT pulmonary angiography (CTPA) is a key diagnostic tool for embolic pulmonary disease during pregnancy, despite its associated high radiation exposure. To minimize the fetal radiation dose, a new technique using internal shielding has been introduced, which reduces internal scattering. This study focuses on evaluating how barium-based internal shielding impacts the reduction of fetal organ radiation dose during CTPA. For instance, a validated GATE/GEANT4 model was used to simulate CTPA acquisition. Fetal organ doses were obtained via a simulated third trimester pregnant model (Katja). In order to simulate internal shielding, Contrast agent (CA) of different sulfate barium concentrations was incorporated in the digestive cavity of the model. Also, fetal organ doses were calculated with and without internal shielding, and levels of fetal organ dose reductions were assessed for all CA concentrations. The mean fetal organ dose for CTPA without CA was 0.71 mGy. According to results, internal shielding induces a reduction in organ dose, since fetal organ dose reductions ranged between 55.89% and 69.41% with 80% CA. Furthermore, it was observed that the more CA concentration increases, the more dose reduction increases. In addition, fetal brain dose was reduced by 55.54%, 59.67%, 61.80%, and 62.94% for CA concentrations of 20%, 40%, 60%, and 80%, respectively. Clearly, this study will help provide a better assessment of fetal dose reduction via barium shielding in CTPA.