Radiation protection dosimetry最新文献

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.

Diagnostic reference levels (DRLs) help optimize panoramic radiography by balancing patient dose and image quality. Cyprus lacks national DRLs, highlighting the need to establish local DRLs (LDRLs) within State Health Services Organization (SHSO) hospitals as a part of quality assurance program. This study assessed imaging conditions for paediatric and adult patients undergoing panoramic radiography at SHSO hospitals to determine LDRLs. Patient data (age, sex), hospital location, exposure parameters, and dose area product (DAP) were extracted from the central PACS using the DOSE (Qaelum NV, Belgium) management system. Radiographs were acquired with four panoramic units at Nicosia General Hospital (NGH), Limassol General Hospital (LiGH), Larnaca General Hospital (LaGH), and Famagusta General Hospital (FGH). Third quartile DAP values were defined as LDRLs for paediatric (< 18 years) and adult (≥ 18 years) groups. DAP and exposure conditions were analysed based on hospital and sex groups. LDRLs were also compared with published reference values. The LDRLs were 116 mGycm2 for paediatric and 119 mGycm2 for adult patients. Mean DAP was significantly lower in paediatric patients (p < .001), although the decrease is relatively small (4%). Tube voltage was significantly higher in adults (p < .001). Significant inter-hospital differences in DAP and exposure parameters were observed (p < .001), with the highest doses recorded at LaGH due to elevated tube voltage and current. Adult males showed higher DAP than females (p < .05); in paediatric patients, significant sex-based differences were observed at NGH and in total dataset. SHSO DAP values were generally higher, except at LiGH and NGH that were comparable to or lower than those in the international literature. This study established LDRLs for panoramic radiography in Cyprus' public hospitals, filling a critical gap in national radiation protection data and supporting legal compliance. The LDRLs may serve as baseline for optimizing dental radiographic practices within the SHSO. Higher DAP compared to international data suggest a need for enhanced dose optimization, particularly in paediatric imaging. Significant inter-hospital differences in DAP and exposure parameters, despite standardized equipment and protocols, highlighting the need for further standardization and quality improvement.

Activity concentrations of radionuclides from the thorium and uranium series, which contribute most to radiation exposure through ingestion in the existing radiation situation, were measured. Activity concentrations were determined in common foods in the Czech Republic. The determination of the activity concentrations was carried out by a combination of radiochemical separation followed by emanometry, gamma spectrometry, or alpha spectrometry. Between 2020 and 2023, 51 "mixed diet" samples were analyzed for 226Ra and 38 for 228Ra. The average daily intake for adults was 30.8 mBq for 226Ra and 32.9 mBq for 228Ra. The annual committed effective dose for adults from food was 3.15 μSv/y for 226Ra and 8.3 μSv/y for 228Ra, both of which are lower than the doses calculated using the reference activity concentrations from the UNSCEAR (2000) report. Similarly, activity concentrations of 226Ra, 228Ra, 238U, and 234U determined in seven common foodstuffs were lower than UNSCEAR (2000). Additionally, analyses of 210Po in leafy vegetables showed the highest median values in lettuce (62-67 mBq/kg of fresh weight) and the lowest in cabbage (7-14 mBq/kg), both comparable with UNSCEAR reference values.