Health physics最新文献

Abstract: Affordable, accurate, and robust temporal measurement devices are desirable for screening and assessment of radon levels in private homes and workplaces. This research expands upon prior research, using the RadonFTlab RadonEye device through a comparison of multiple samples of this instrument with a laboratory-grade instrument, the Saphymo AlphaGUARD, over a more extensive period than reported previously. Data were collected over 291 d in a poorly ventilated basement space in an occupied building. Environmental conditions varied naturally, changing both the radon source term and radon entry into the space approximating typically deployed conditions. The R-squared linear regression correlation coefficient and relative sensitivities of each RadonEye with the AlphaGUARD were computed. Overall temporal and diurnal variations were also studied. The sensitivities of all RadonEyes and the AlphaGUARD agreed to within 22% throughout the entire deployment period.

Abstract: A comprehensive radiological study was conducted in the surrounding public zones of the Nevada National Security Site to identify traces of resuspended radioactivity and heavy elemental contamination that might have resulted from various activities. The study used passive and active nuclear methods, specifically gamma spectrometry and instrumental neutron activation analysis, respectively. Passive gamma spectra analysis of air filter papers from various Community Environmental Monitoring Program stations conclusively verified the presence of radionuclides exclusively originating from the natural decay series of 238 U and 232 Th. Furthermore, gamma spectrometry and instrumental neutron activation analysis of plant samples from surrounding areas of the Nevada National Security Site revealed the absence of any unusual elemental contamination in the environment. These results demonstrated that there was no measurable radiological impact on the public zones surrounding the site resulting from the spread of radioactive materials or toxic heavy metals associated with previous or ongoing activities at Nevada National Security Site. Therefore, the safety of public zones concerning retained radioactivity and harmful elemental contamination arising from Nevada National Security Site operations is negligible. The significance of this study is further pronounced in the current geopolitical context, as it establishes the baseline elemental composition for various desert plants for future reference.

Abstract: Nuclear safety and security are essential elements of radiation protection. Integration of nuclear safety and security provides a means to identify conflict and synergy points. Research has not been performed to enable integrated practices at the facility level. A tool was developed through research to help staff and regulators assess the level of integration practiced within a research reactor. This tool aims to improve the identification of synergistic and conflict points. Eight criteria of nuclear safety and security integration were used to create the integration assessment tool: access control, transportation, emergency response, proper disposal of materials, testing and maintenance, defense in depth, training and education, and culture. The tool's final score can range from 0.0375 to 1, with a score of 1 indicating complete integration. The tool was used by research reactor staff to assess practiced integrative techniques. The testing and maintenance criterion scored the highest level of integration (0.84). Training and education and culture scored the lowest levels of integration (0.50). The areas with the highest scores identified points of actively practiced integration. In contrast, those areas with lower scores indicated a lack of integrative practices. The total integration score was 0.69. This tool determined that the facility practiced an adequate level of integration. By analyzing integration levels with this tool, a measurable standard of integrative practices can be employed to achieve improved radiation protection.

Abstract: At the University of Alabama at Birmingham (UAB), many diagnostic and therapeutic procedures involving radioactive materials or radiation-producing machines are performed daily. A growing number of minor but preventable incidents related to radiation safety have brought up concerns related to the effectiveness of the training program. A comprehensive literature review was performed to summarize post-COVID insights into andragogic online training practices, statistical analyses, and overall retention competencies in radiation safety. Andragogic research shows that the best method of training adult learners is controlled simulation that tests critical thinking and problem-solving capabilities, drawing upon previous knowledge or experiences. A new training curriculum based on these andragogic principles was designed and administered to a subgroup of UAB radiation workers. Scores from pre-testing and post-testing were collected and analyzed. An ANCOVA was used to account for differences in the pre-test scores between the control and experimental groups, which was found to be statistically significant (p = 0.018), suggesting that small changes in a radiation safety training program can have significant impacts in retention of key information.

Abstract: Radiation protection contains the key elements of nuclear safety and security. Despite the overlap between nuclear safety and security, their objectives differ fundamentally, focusing on unintentional accidents and intentional malicious events, respectively. As such, the Potential Facility Risk Index (PFRI), originally created for security purposes, has evolved into an approach that combines conventional probabilistic risk assessment (PRA), which is a widely employed method to evaluate the safety risks of nuclear facilities. This research has developed a risk assessment model within the PFRI framework to calculate the probability of nuclear terrorism. Three essential components of the model are integrated: an analysis of historical nuclear terrorism data to determine an initial threat frequency; the target-specific factor using analytical hierarchy process (AHP) target attractiveness analysis; and the adversary motivation factor based on site-specific social influences from the Profiles of Individual Radicalization in the United States (PIRUS) dataset. Applied to a hypothetical nuclear facility, the model produces a nuclear terrorism probability of 8.97 × 10 -3 y - 1 . The systematic methodology proposed in the study enables the derivation of nuclear terrorism probability with results in the same risk unit as safety risk assessment. This method allows decision makers to seamlessly incorporate nuclear safety and security risk assessments, offering a comprehensive perspective. Consequently, it enriches comprehension of nuclear facility risks and establishes the groundwork for future advancements.

Abstract: Three topics related to ANSI/HPS Standard N13.56, Sampling and Monitoring Releases of Airborne Radioactivity in the Workplace, are discussed. First, due to the omission of consideration of the activity's half-life in the standard's continuous particulate air monitor (CPAM) quantitative method, it is possible for concentration estimates produced by that calculation to be underestimated. Second, the concentration estimate found in air grab sampling, as discussed in the standard, is not, as claimed, an average unless the activity is "long-lived" (negligible decay during sampling). It is nonetheless possible for this calculation to produce a concentration estimate that is not significantly different from the average, depending on both the half-life of the activity and the sampling time. Third, the issue of when to change the filter for the CPAM method is addressed.

Abstract: The roles and responsibilities of radiation safety officers (RSO), medical health physicists (MHP) and diagnostic medical physicists (DMP) have evolved significantly over the past 20 years. With the availability of enterprise software systems and aggregated data platforms for various radiologic healthcare systems, the roles of these professions are expanding beyond their original scopes in managing the Radioactive Materials License (RSO, MHP) and Machine Specific Physics Testing (DMP). Workers in medical radiation safety are transitioning from siloed workers working within their specific disciplines as new emerging technology and clinical care require these roles to evolve. This paper aims to demonstrate the value in embracing the change in these roles to better serve the patients and occupational workers RSOs, MHPs, and DMPs serve. As medical physics enterprise solutions evolve, so will the relationships between these valuable stakeholders.

Abstract: In this study, the occupational radiation dose, radon gas, and non-ionizing radiation doses originating from electromagnetic fields (EMF) to which radiation workers are exposed were monitored and evaluated for 1 y. Using electronic personnel dosimeters (EPD), average daily radiation doses based on the number of patients and annual average effective dose results of radiation workers were obtained over a period of 1 y. Also, the annual effective dose and risk values were calculated for 8 h and 24 h by taking radon gas measurements at 2-mo intervals in the nuclear medicine department. Finally, electric field measurements were made one day a week in the selected areas. All the results obtained were compared with national and international dose limits. The results obtained as a result of EPD, radon gas, and EMF measurements made in the nuclear medicine department were found to be far below the international and national legal dose limits.

Abstract: In reviewing a video series that they created for the website of the Health Physics Society (HPS), past leaders of the Health Physics Society have treated as authoritative and trustworthy the scientific misconduct theories of University of Massachusetts Professor Edward Calabrese. No mention is made of detailed critiques of Calabrese's work. I show that Calabrese's historical work as presented by HPS's authors is unreliable because it overlooks key historical text and key statistical concepts about the limits of an early atomic bomb genetics study. When these errors are corrected, claims of scientific misconduct on the part of historical figures evaporate. Claims of threshold behavior in early radiation genetic experiments are wrong for atomic bomb data. Calabrese's unique claims about thresholds in early animal genetic data are not credible for human cancer, given the doses at which they were carried out (>30 R). Recent epidemiological studies of both acute and protracted exposure in humans fail to show dose-rate effects or a dose threshold above 30 R. Such results from human data should be more relevant for most regulators and review committees than Calabrese's claims about old data on animals. Disclaimers, errata, and links to critiques should be added to the HPS webpage hosting the 22-part video series. Failure to do so can cause damage to reputations and historical accuracy because it erroneously validates Calabrese's inflammatory claims of scientific misconduct against past scientists, including three Nobel Prize winners, members of the NAS, and presidents of the AAAS.

Abstract: Objectives: To analyze the effects of normal x-ray inspection, machine washing, and machine drying on thermoluminescent dosimeter (TLD) measurements during external individual monitoring and to provide suggestions for determining individual monitoring measurements under the mentioned abnormal situations. In this study, we focused on three abnormal situations: x-ray inspection, machine washing, and machine drying, which are common in external individual dose monitoring. We measured and compared the doses from TLD with and without 11, 23, 35, and 50 security checks. We used different radiation sources to expose the TLDs before or after machine washing with or without hot drying. The three radiation sources are natural background radiation, 137 Cs γ rays, and 320 kVp x-rays. We measured 20 TLDs for each situation. The average doses for the TLDs with 11, 23, 35, 50 security checks are 27.7 μGy, 59.7 μGy, 84.1 μGy, and 121.0 μGy, respectively. We measured an average dose of 2.5 μGy per exposure. The doses showed no significant difference between different times of washing with different radiation sources, natural background radiation, 137 Cs, or x-ray exposures. There was also no significant difference between the dose coming from the controlled group, drying at 60 °C and 90 °C for 1 h after exposure to 137 Cs γ rays and 320 kVp x-rays. The common machine drying under the temperature of 90 °C did not affect TLD measured doses.