Radiation protection dosimetry最新文献

Volumetric modulated arc therapy for pediatric medulloblastoma improves target precision but increases low-dose exposure to healthy tissues, elevating secondary cancer risks. This study evaluates treatment planning system (TPS) accuracy for out-of-field dose (OOFD) predictions by performing measurements with optically stimulated luminescence dosemeters (OSLDs) in an anthropomorphic phantom. TPS predictions were accurate near the field (<3% at 5.5 cm) but significantly underestimated doses at larger distances, with discrepancies ranging from 16% (thyroid) to 64% (heart). These findings highlight TPS limitations in modeling peripheral leakage and scatter and underscore the critical role of OSLD-based monitoring for pediatric patients. Accurate OOFD verification is essential for risk assessment and long-term safety. Future work should focus on refining TPS algorithms and integrating direct dosimetry into clinical practice for this vulnerable population.

This study provides an evaluation of public health and economic impacts following a hypothetical nuclear accident. Using the Pasquill-Gifford (PG) atmospheric stability classification, simulations were conducted with HotSpot Health Physics to determine the total effective dose equivalent (TEDE) and associated excess relative risk (ERR) for radiation-induced leukemia. Risk estimates were obtained through the biological effects of ionizing radiation V and VII radioepidemiological models, considering age- and sex-specific vulnerability across various exposure zones. The Geographic Information Systems (GISs), combined with demographic data, enabled stratified analysis. The results reveal differences in exposure and risk patterns that are influenced by environmental conditions, demography, and atmospheric stability. Furthermore, this study introduces a cost-assessment approach based on ERR-adjusted radiation dose distributions, offering a conservative perspective on the economic impact of radiological health effects. The work also emphasizes the significance of demographic sensitivity and conservative latency assumptions in fostering resilient medium-term public health strategies.

ICRP 103 guidelines and EURATOM Directive 2013/59 require close monitoring of radioactive emissions, ensuring that public exposure remains below 10 $mu $Sv/year. To meet these limits, reliable and accurate monitoring systems are essential. This study presents a method for calibrating large-area proportional counters used for monitoring the emissions of $^{18}F$ and $^{11}C$ gases during the production of PET radiopharmaceuticals. The proposed method makes it possible to accurately determine the calibration factor for measuring the air activity concentration. In addition, the efficiency of absolute and activated carbon filters in reducing radioactive emissions was evaluated. The results showed a filtration efficiency of 98$%$. This underscores the importance of combining detection system with efficient air filtration to ensure that radionuclide production facilities remain within regulatory limits, protecting both public health and the environment.

The current activities of the Korean Biological Dosimetry Network (K-BioDos) have focused on harmonizing the scoring of chromosomal aberrations. However, other biodosimetry procedures have not been sufficiently considered in preparation for large-scale radiological accidents. This study aimed to investigate the current status of various resources for performing cytogenetic biodosimetry on many samples and explore the limitations and future directions for analyzing large sample sizes. Although the capacity to score cytogenetic aberrations has improved, processing thousands of samples within a limited period remains a significant challenge. To further enhance biodosimetry performance, we recommend the establishment of automated systems for sample handling and increased government support to ensure adequate material resources. Additionally, we highlight the importance of developing strategies to assess occupationally exposed populations. These measures could enable K-BioDos and other national and international networks to establish comprehensive frameworks for dose assessment in large-scale radiological incidents.

This study investigated occupational external exposure levels and trends among industrial radiation workers in Jiangsu Province during 2010-2018. Utilizing thermoluminescence dosimetry for personal dose monitoring and Kruskal-Wallis test for inter-group comparisons, we analyzed radiation exposure across occupational categories. Results revealed an annual effective dose range of 0.16-0.58 mSv (mean: 0.26 mSv), exhibiting an initial increase followed by subsequent decline. While all values remained significantly below the national limit of 20 mSv, significant inter-category differences were observed (H = 35.282, P < 0.05). Industrial flaw detection workers demonstrated particularly elevated exposure levels, with some cases exceeding annual limits. These findings highlight the necessity for reinforced protective measures, enhanced monitoring protocols, and comprehensive training initiatives to mitigate occupational radiation risks in this vulnerable subgroup.

In Korea, coal-fired power plants manage fly ash by landfilling, which can cause radiological impacts on the general public. Therefore, a radiation dose assessment must be performed to verify the radiological safety of the general public around the coal-fired power plant. The objective of this study is to assess the radiation dose to the general public in Korean coal-fired power plants. To achieve this, we investigated the radioactivity concentration of fly ash generated from coal-fired power plants. The exposure scenarios were established based on the purpose of the site utilization and characteristics of the general public. The RESRAD-OFFSITE was used to assess the radiation dose. The radiation dose ranged from 2.36 × 10-5 ~ 5.60 × 10-2 mSv yr-1, which was lower than the annual dose limit regulated by the Nuclear Safety Act. The results of this study can be used as technical data for the radiological safety management of a Korean naturally occurring radioactive material facility.

This study aims to determine effective energy and scattered radiation distributions in an interventional cardiology department. Additionally, the protective effectiveness of ceiling-suspended shielding was investigated. Optically stimulated luminescence dosemeters were attached to mica rods to determine effective energy and scattered radiation at numerous points in the catheterization laboratory. The effective energy of the scattered beam ranged from 40 to 50 keV, with the beam scattered to the eye position reaching an effective energy of 45 keV. Radiation was distributed nonuniformly at different locations and heights. Ceiling-suspended shielding reduced the dose to the head and neck region but did not significantly affect other regions. The combination of a suitable standing position and ceiling-suspended shielding can notably diminish the staff's eye dose by >93%.

In this paper, we have assessed the specific absorption rate (SAR) in fetal brain and lungs during the second trimester of pregnancy conditions of body exposure to radiofrequency electromagnetic field (RF-EMF). SAR calculations were performed for frontal and lateral incidences, with both vertical and horizontal polarization of the incident electromagnetic (EM) waves at frequencies ranging from 2.45 to 5 GHz. A realistic pregnant human model with a belly button piercing was implemented for numerical simulation for nonionizing dosimetry. The simulation results reveal that SAR tends to rise in the presence of belly-button piercing. The highest SAR10g recorded on the fetus's lungs was 16 mW/kg at a frequency of 2.45 GHz. Similarly, the maximum SAR10g value on the fetus's brain was measured 14 mW/kg, occurring at a frequency of 2.45 GHz. Results indicate that metal objects can lead to an increase in SAR values. However, obtained values remain below limits set by international organizations like the Institute of Electrical and Electronics Engineers and the International Commission on Non-Ionizing Radiation Protection.