Objective: To establish testing and evaluation methods for radiation shielding performance of a self-shielded radiotherapy system by measuring the radiation levels around the self-shielded head and neck radiotherapy system. Methods: A total of 14 monitoring points were selected outside the restricted zone of the system. Under radiation conditions from five different fixed directions, an ion chamber survey meter was used to measure and identify the maximum ambient dose equivalent rate at the 14 points. The time-averaged dose rate was then calculated based on the workload. In accordance with relevant radiation protection standards, an instantaneous dose rate of 10 μSv/h and a time-averaged dose rate of 2.0 μSv/h were proposed as the criteria for shielding protection evaluation. Results: Based on the ambient dose equivalent rates at the 14 monitoring points outside the restricted zone, the maximum instantaneous dose rate outside the restricted zone was 7.4 μSv/h. With a workload of 15 patients per day, the maximum time-averaged dose rate was 1.0 μSv/h, which can be used as the criteria for shielding protection evaluation. Conclusion: By considering both instantaneous dose rate and time-averaged dose rate, a comprehensive safety assessment of the radiation shielding performance of a self-shielded radiotherapy system can be conducted.
Objective: Ionization chamber detector is commonly used for direct and continuous measurement of tritium concentration in the air. However, the measurement sensitivity is low due to the limitations of weak current measurement technology. It is necessary to develop a proportional counter for measuring tritium in the air. Methods: This study involved the design of a proportional counter, considering various factors such as materials and structure. The stability, plateau curve, detection efficiency, and energy spectrum of the counter were tested. Results: The coefficient of variation of the proportional counter was 3.14%, which met the standard requirement of being less than 15%. The plateau length was 260 V and the plateau slope was 0.80%/100V, which met the requirement of being less than 1%/100V. The tritium detection efficiency reached 68.02%. The energy spectrum measurement indicated a significant difference between tritium signal generated by the proportional counter and background signal, and the distribution of tritium in the energy spectrum was more concentrated. The background counting rate during tritium gas activity measurement could be reduced through energy spectrum measurement. Conclusion: The proportional counter can provide a reference for the direct and continuous measurement of tritium in the air.
Objective: To assess the retention and excretion fractions for uranium intake via wounds in the organs of adult reference computational phantom, and to improve the evaluation of health risks associated with radioactive isotopes intake via wounds. Methods: A software for evaluation of the internal radiation dose was developed by combining the wound model in International Commission on Radiological Protection Report 156 and the systemic models in the International Commission on Radiological Protection Report 130 and the subsequent Occupational Intakes of Radionuclides series reports. This study was conducted to calculate the uranium retention fractions in adult reference individuals following ingestion through wounds of seven categories of uranium: weakly retained, moderately retained, strongly retained, very strongly retained, colloids, particles, and fragments. We assessed the retention fractions in the wound sites, bones, and liver, as well as the excretion fractions in urine and feces, and compared these results with authoritative results. Results: The retention and excretion fractions of 238U and 235U in different forms of intake via wounds showed consistent variations. The retention fractions of weak and moderate uranium in wounds could be ignored after 1 000 d. The retention fractions of strong, avid, and colloid uranium were 10−4 to 10−5 after 10 000 d. A significant portion of the uranium present in the forms of particles and fragments exhibited long-term retention in wounds. The bone retention fractions were 1 to 2 orders of magnitude higher than the liver retention fractions. Following the intake of soluble and insoluble uranium, the retention fractions in these two organs decreased and increased, respectively, compared with those observed on the first day. The urinary excretion fractions were approximately 2 orders of magnitude higher than the fecal excretion fractions. Following the intake of soluble and particulate uranium, the excretion fractions decreased. At 1 000 d after the intake of uranium in the form of fragments, the urinary and fecal excretion fractions were 10−6 and 10−8, respectively. Conclusion: The calculation results validated the accuracy of the established models, providing data support for the assessment of internal exposure doses in individuals following uranium wound contamination incidents.
Objective: To compare the results of accumulation and continuation methods in indoor radon measurement. Methods: The radon concentrations in 30 households in 7 provincial capital cities of China were simultaneously measured using both accumulation and continuation methods. Results: The radon concentration measured by accumulation method in 30 households ranged from 21 to 323 Bq/m3, with a median M(P25, P75) of 70.5 (43.8, 111). The radon concentration measured by the continuation method ranged from 16.1 to 258 Bq/m³, with a median M(P25, P75) of 100 (51.3, 141). The average relative percent deviation between the two measurement methods was 41.8%. There were significant differences among the measurement results at 8, 16, and 24 h by the continuation method. Pairwise comparisons showed there were statistical diffferences between 8 h and 16 h, as well as between 8 h and 24h; however, no statistical significance was found (P < 0.05), between 16 h and 24 h. Conclusion: The overall continuous measurement results of the 30 households were higher than those of cumulation method. The comparison between accumulation and continuation measurement results did not show a high level of correlation (r=0.49). The continuation method is significantly affected by environmental factors, and the length of the measurement period can affect the measurement results. The selection of indoor radon measurement methods should consider the purpose, sample size, and environmental conditions.
Objective: Developing a new type of full-face respiratory protective mask for nuclear facility sites to enhance the sound transmission function and improve the facial adaptability. Methods: Combined with feedback from on-site practical needs, this study utilized finite element simulation and ergonomic design methods to investigate the voice transmission units of full-face masks and the facial features of workers at key nuclear facilities. Based on the research results, a new full-face respiratory protection mask structure was designed. Results: The optimized structure of passive thin film voice transmission unit significantly enhanced voice transmission efficiency, reducing average voice transmission loss by approximately 70% compared to the control group using thin plate units of equivalent thickness. The existing facial feature test panels insufficiently cover and unevenly classify the facial features of workers at key nuclear facilities. In this study, a specialized test panel based on measurement data achieved a total coverage of 98.5% with high distribution uniformity within each class, providing effective guidance for redesigning full-face mask structural parameters. In comparison to foreign products currently utilized in nuclear facilities, the newly designed full-face mask structure exhibited excellent tightness and structural safety and reliability, and can be cleaned, decontaminated, and reused. Conclusion: The results of this study provide significant guidance for improving and optimizing full-face respiratory protection mask used at nuclear facilities, as well as promoting domestic production of high-quality full-face respiratory protection masks.
Objective: With the increase in pet-owning households in China, veterinary clinics have increased at an annual rate of 19.86%. However, the management blind area that may exist in multi-department supervision has led to a significantly worse working environment of radiation workers in veterinary clinics than that of medical institutions. The purpose of this study was to understand the levels of occupational external exposure of radiation workers in veterinary clinics in China, analyze the occupational risks faced by radiation workers in veterinary clinics, contribute to the protection of the occupational health of radiation workers, and provide data and scientific basis for the formulation of national relevant regulations and standards. Methods: The individual dose monitoring data of radiation workers in selected veterinary clinics in 2022 were obtained from the National Individual Dose Registration System. Results: This study involved 1868 radiation workers from
Objective: To investigate the gross α and gross β radioactivity in Dongjiang River during high and low flow periods in Dongguan City, China, and evaluate the radiation safety status of Dongjiang River as a source of drinking water. Methods: The gross α and gross β radioactivity levels were measured in the source water, treated water, and tap water from eight water treatment plants along the Dongjiang River, which relied on Dongjiang River water as their source, during both high and low flow periods. The annual internal effective dose from consuming Dongjiang River water was estimated. Results: In high flow period, the gross α and gross β radioactivity levels were 0.016-0.041 and 0.063-0.140 Bq/L for source water, 0.011-0.039 and 0.064-0.131 Bq/L for treated water, and 0.013-0.024 and 0.078-0.127 Bq/L for tap water. In low flow period, the gross α and gross β radioactivity levels were 0.012-0.029 and 0.055-0.141 Bq/L for source water, 0.012-0.019 and 0.054-0.124 Bq/L for treated water, and 0.012-0.024 and 0.083-0.134 Bq/L for tap water. The estimated total effective doses of gross α and gross β radioactivity caused by consumption of water from Dongjiang River were 3.6 and 0.48 μSv/a, respectively. Conclusion: The gross α and gross β radioactivity levels of water from Dongjiang River in Dongguan City are below the radioactive indicator values specified in the Standards for Drinking Water Quality (GB 5749-2022), remaining within the range of natural environmental background. The annual internal effective dose caused by consumption of water from Dongjiang River is below the individual dose limit set in the Guidelines for Drinking Water Quality.
Objective: To investigate the external radiation doses and occupational health examination data of radiation workers in medical institutions in Zhangjiagang City, China, explore the effects of long-term exposure to low-dose ionizing radiation on their health, and provide a reference for occupational health monitoring. Methods: The radiation workers of medical institutions in Zhangjiagang City were selected as the research subjects. Their personal radiation doses and occupational health examination data were collected. A scale was used for mental health survey. The data were analyzed according to different clinical characteristic groups. Results: During the 5-year period from 2019 to 2023, the average annual radiation dose received by radiation workers in medical institutions in Zhangjiagang City was 0.21 mSv/year. There were significant differences in the average annual radiation dose across these years and radiation workers with different occupations. The results of occupational health examinations showed significant difference in the total abnormal detection rate among these years (P < 0.01). There were significant differences in the abnormal rates of blood pressure, blood routine, and electrocardiogram across these years (P < 0.05). There were significant differences in the abnormal rate of routine blood test in radiation workers with different sexes, years of service, and radiation occupations (P < 0.01). There were significant differences in the abnormal rate of blood pressure in radiation workers with different sexes, ages, and years of service (P < 0.01). The mental health survey showed significant differences between the radiation and the non-radiation groups in terms of occupational stress, anxiety score, and depression score (P < 0.05). Conclusion: Long-term low-dose ionizing radiation may have adverse effects on the physical and mental health of radiation workers, and it is necessary to strengthen the occupational health examination and radiation protection of radiation workers.
After the Three Mile Island, Chernobyl, and Fukushima nuclear accidents, numerous issues were exposed during the emergency evacuation process, such as insufficiently detailed emergency plans, lack of specific evacuation route schemes, inadequate preparation of emergency protective materials, and delays in emergency response decision-making. Additionally, these accidents revealed serious issues with the emergency evacuation of vulnerable populations. In particular, during the Fukushima nuclear accident, the lack of resource support led to deteriorating health and fatalities among hospital patients and elderly residents in nursing homes near the nuclear power plant during emergency evacuation. To learn from the experiences and lessons of public protection actions in emergency evacuations during major nuclear accidents, the government should enhance the guidance of nuclear emergency evacuation plans, increase the quality of emergency training and exercises, and improve their specificity and continuity, as well as establish an efficient nuclear emergency rescue response and decision-making mechanism. For vulnerable populations in nuclear emergency evacuations, the government should consider updating the nuclear emergency plans and disaster preparedness material reserves of medical facilities (such as designated treatment hospitals) and elderly facilities (such as nursing homes) within the emergency protection action areas of nuclear power plants in a timely manner. This will ensure that these institutions have the capacity to provide initial evacuation and necessary support for vulnerable populations in disaster situations.
Objective: To investigate and analyze the current situation of radiation protection in non-medical radiation institutions in Nantong, China, 2023, and to provide data support for local health supervision departments to formulate more scientific and reasonable occupational health management measures. Methods: Based on the radiation health information management platform of Jiangsu Province, the data reported in 2023 were collected through online questionnaire survey. Seven institutions were selected for on-site test. The survey and test data were analyzed. Results: There were
Objective: To analyze the status of youth funds and fund management in radiation health research institutes, and to explore the contribution of institutional funds to the cultivation of young scientific and technological talents in the field of radiation health . Methods: The scientific archives of youth funds from 2003 to 2023 were collected for analyses from the aspects of organization and management, application and review, cycle, funding amount, research field, the person in charge of the program, acceptance, and achievements. Statistical analyses were carried out in Excel 2019. Results: The institution-supported Youth Director Funds had a two-year implementation period. A total of 68 funds were granted with a cumulative funding amount of
Objective: To study the impact of high radon exposure in non-uranium mines on the occupational health of miners in Jiayuguan, China. Methods: Miners with high radon exposure in non-uranium mines who underwent occupational health examinations at the designated occupational disease specialist hospitals in 2020-2022 were selected as the exposure group (167), and people with no history of radon exposure during the same period were selected as the control group (134). The health examination data of the two groups were collected for statistical analysis. Results: In the exposed group, the rates of ophthalmologic examination abnormality, electrocardiogram abnormality, micronucleus test abnormality, chromosomal aberration, pulmonary nodule detection, liver function abnormality, and leukocyte abnormality were 1.20%, 4.79%, 0%, 0.60%, 37.13%, 43.71%, and 16.77%, respectively. The detection rates of pulmonary nodules and leukocyte abnormalities in the exposed group were significantly higher than those in the control group (P < 0.05). The detection rate of pulmonary nodules increased with working age in the exposed group (P < 0.05). Among different types of work, the detection rates of pulmonary nodules were relatively high in internal combustion overhaul workers, filling workers, and ore carriers (P < 0.05). The rate of liver function abnormalities increased with age (P < 0.05). The rate of leukocyte abnormalities increased with the increase in working age (P < 0.05). Conclusion: Radon exposure has a detrimental effect on the health of non-uranium mine workers, which is mainly manifested by increased detection rates of pulmonary nodules and leukocyte abnormalities. Targeted preventive measures need to be taken to protect the health of miners.
Objective: To examine the impact of medical ionizing radiation on human blood cell and biochemical parameters, so as to provide insights into formulation of radiation protective interventions. Methods: The health examination data of healthcare workers on radiative diagnosis (X-rays and CT scans), interventional therapy and radiation therapy in Wuxi Municipal People’s Hospital from October 2007 to March 2024 were retrospectively collected, and 300 healthcare workers in the same hospital during the study period without exposure to ionizing radiation served as controls. The blood cell and biochemical parameters were measured and compared between healthcare workers with and without radiation exposure. Results: There were no significant differences between healthcare workers with and without radiation exposure in terms of gender distribution (χ2 = 0.317, P > 0.05) and mean age (t = 0.519, P > 0.05). There were significant differences between healthcare workers with and without radiation exposure in terms of white blood cell counts (t = 11.273, P < 0.01), lymphocyte counts (t = 6.102, P < 0.01), hemoglobin level (t = 67.237, P < 0.01), alanine transaminase (t = 6.234, P < 0.01), aspartate transaminase (t = 4.231, P < 0.01), gamma-glutamyl transferase (t = 8.010, P < 0.01), total bilirubin (t = 5.212, P < 0.01), and proportions of abnormal alanine transaminase (χ2 = 4.481, P < 0.01), gamma-glutamyl transferase (χ2 = 10.552, P < 0.01) and total bilirubin levels (χ2 = 35.661, P < 0.01). Conclusion: Long-term low-dose ionizing radiation may affect human blood cell and biochemical parameters.
Objective: To assess the value of cone-beam computed tomography (CBCT) in evaluating the response of unresectable liver cancer to transarterial chemoembolization (TACE). Methods: A total of 55 unresectable liver cancer patients with 90 lesions who received TACE at the First People’s Hospital of Liangshan Yi Autonomous Prefecture between July 2021 and July 2023 were enrolled in the study. The response to TACE was evaluated using the modified Response Evaluation Criteria in Solid Tumors one month post-treatment. The value of lesion diameter, volume, and density on CBCT images in predicting the response to TACE was assessed using the area under the receiver operating characteristic curve. Results: Of the 55 patients treated with TACE, 26 achieved complete response, 17 achieved partial response, 9 showed stable disease, and 3 had progressive disease. Of the 90 lesions, 48 achieved complete response, 20 achieved partial response, 17 showed stable disease, and 5 had progressive disease. On CBCT images, the mean diameter, volume, and density of lesions with complete and non-complete responses were (20.9 ± 9.9) mm, (
At present, the incidence and mortality of tumors are increasing, and the treatment of tumors has attracted much attention. Radiotherapy is a key method for tumor treatment; however, its effectiveness is often constrained by radioresistance. During tumor radiotherapy, DNA damage response (DDR) is a key factor in the radioresistance of tumor cells. Research has shown that the radiosensitivity of tumor cells can be effectively improved by regulating the expression of key proteins in the DDR pathway. Targeting the DDR signaling pathway has become an effective strategy to reduce tumor radioresistance. This article focuses on the mechanisms, clinical research status, limitations, and current challenges associated with the key DDR proteins DNA-PKcs, ATM, ATR, and PARP as therapeutic targets for tumor radiotherapy sensitization, in order to provide a reference for the development of radiotherapy sensitization agents.
The number of interventional procedures has increased significantly due to the advantages of minor trauma, rapid recovery, and low incidence of complications. In 2018, there were approximately 24 million interventional procedures worldwide, representing a six-fold increase compared with 3.6 million procedures in 2008. From 2020 to 2021, the percentage of medical institutions with independent interventional departments in China increased from 50.49% to 63.18%. Interventional procedures inherently involve exposure to ionizing radiation, which poses a greater risk of radiation-related harm to the pediatric population due to their increased sensitivity, Consequently, the radiation dose levels experienced by children undergoing these procedures have become a growing concern, emerging as a focus of research both nationally and internationally. This article summarizes the reports published by the International Commission on Radiological Protection (ICRP), the National Council on Radiation Protection and Measurements (NCRP), and the International Atomic Energy Agency (IAEA) as well as academic articles, and reviews the dose optimization measures in the interventional procedures for pediatric patients. Regular radiation safety training for interventional radiation workers, enhancing radiation safety awareness, optimizing intraoperative techniques, and timely updating imaging equipment can effectively reduce the radiation dose received by pediatric patients. This approach helps reduce the doses to an acceptable range while still meeting interventional procedural requirements, thereby protecting the physical health of pediatric patients.
With the widespread adoption of technologies such as diagnostic imaging, interventional medicine, radiotherapy, and nuclear medicine, a growing number of people are exposed to low-dose ionizing radiation. Currently, the biological effects of low-dose radiation remain unclear, necessitating the identification of sensitive and specific biomarkers for risk assessment and health monitoring of such exposure. In this paper, we review the latest research progress in low-dose ionizing radiation biomarkers from the five perspectives of cytogenetics, DNA damage, transcriptome, proteome, and metabolomics. This review aims to provide a theoretical basis for the study of the biological effects of low-dose radiation.