• Proceedings of the Korean Radioactive Waste Society Conference
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.247-248
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• 2018

• Nuclear Engineering and Technology
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• 제52권8호
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• pp.1826-1833
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• 2020

Administration of stable iodine has been considered a best measure to protect the thyroid from internal irradiation by radioiodine intake, and its efficacy on thyroid protection has been quantitatively evaluated in several simulation studies on the basis of simple iodine biokinetic models (i.e., three-compartment model). However, the new iodine biokinetic model adopted by the International Commission on Radiological Protection interprets and expresses the thyroid blocking phenomenon differently. Therefore, in this study, the new model was analyzed in terms of thyroid blocking and implemented to reassess the protective effects and to produce dosimetric data. The biokinetic model calculation was performed using computation modules developed by authors, and the results were compared with those of experimental data and prior simulation studies. The new model predicted protective effects that were generally consistent with those of experimental data, except for those in the range of stable iodine administration -72 h before radioiodine exposure. Additionally, the dosimetric data calculated in this study demonstrates a critical limitation of the three-compartment model in predicting bioassay functions, and indicated that dose assessment 1 d after exposure would result in a similar dose estimate irrespective of the administration time of stable iodine.

• Journal of Korea Multimedia Society
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• 제7권7호
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• pp.934-943
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• 2004

In this paper, we propose cookie protection-key management system for cookie protection and maintain separate cookie protection-key of each user. We provide integrity, confidentiality, and user authentication of cookie by using registered cookie protection-key and applying encryption techniques. And, we use the technique for hiding the URL of an internal document to a user to minimize the problem of its exposure. When this system is applied to the intranet of an enterprise, it will be able to provide a security to cookie and minimize the problem of internal document exposure by an internal user.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2606-2613
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• 2022

Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs ¹⁴C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted ¹⁴C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0-6 bar and 0-150 ℃, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

• Journal of Radiation Protection and Research
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• 제49권1호
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• pp.1-18
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• 2024

Exponential growth has been observed in nuclear medicine procedures worldwide in the past decades. The considerable increase is attributed to the advance of positron emission tomography and single photon emission computed tomography, as well as the introduction of new radiopharmaceuticals. Although nuclear medicine procedures provide undisputable diagnostic and therapeutic benefits to patients, the substantial increase in radiation exposure to nuclear medicine patients raises concerns about potential adverse health effects and calls for the urgent need to monitor exposure levels. In the current article, model-based internal dosimetry methods were reviewed, focusing on Medical Internal Radiation Dose (MIRD) formalism, biokinetic data, human anatomy models (stylized, voxel, and hybrid computational human phantoms), and energy spectrum data of radionuclides. Key results from many articles on nuclear medicine dosimetry and comparisons of dosimetry quantities based on different types of human anatomy models were summarized. Key characteristics of seven model-based dose calculation tools were tabulated and discussed, including dose quantities, computational human phantoms used for dose calculations, decay data for radionuclides, biokinetic data, and user interface. Lastly, future research needs in nuclear medicine dosimetry were discussed. Model-based internal dosimetry methods were reviewed focusing on MIRD formalism, biokinetic data, human anatomy models, and energy spectrum data of radionuclides. Future research should focus on updating biokinetic data, revising energy transfer quantities for alimentary and gastrointestinal tracts, accounting for body size in nuclear medicine dosimetry, and recalculating dose coefficients based on the latest biokinetic and energy transfer data.

• Journal of Radiation Protection and Research
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• 제45권2호
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• pp.53-68
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• 2020

Background: International organizations such as the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported public exposure doses due to radionuclides released in the Fukushima nuclear accident a few years after the event. However, the reported doses were generally overestimated due to conservative assumptions such as a longer stay in deliberate areas designated for evacuation than the actual stay. After these reports had been published, more realistic dose values were reported by Japanese scientists. Materials and Methods: The present paper reviews those reports, including the most recently published articles; and summarizes estimated effective doses (external and internal) and issues related to their estimation. Results and Discussion: External dose estimation can be categorized as taking two approaches-estimation from ambient dose rate and peoples' behavior patterns-and measurements using personal dosimeters. The former approach was useful for estimating external doses in an early stage after the accident. The first 4-month doses were less than 2 mSv for most (94%) study subjects. Later on, individual doses came to be monitored by personal dosimeter measurements. On the basis of these measurements, the estimated median annual external dose was reported to be < 1 mSv in 2011 for 22 municipalities of Fukushima Prefecture. Internal dose estimation also can be categorized as taking two approaches: estimation from whole-body counting and estimation from monitoring of environmental samples such as radioactivity concentrations in food and drinking water. According to results by the former approach, committed effective dose due to ¹³⁴Cs and ¹³⁷Cs could be less than 0.1 mSv for most residents including those from evacuated areas. Conclusion: Realistic doses estimated by Japanese scientists indicated that the doses reported by WHO and UNSCEAR were generally overestimated. Average values for the first-year effective doses for residents in two affected areas (Namie Town and Iitate Village) were not likely to reach 10 mSv, the lower end of the doses estimated by WHO.

• Tuberculosis and Respiratory Diseases
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• 제41권6호
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• pp.651-657
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• 1994

Asbestos is widely used in the textile, asbestos cement, construction products, friction material, paper products, insulation products, chemical and plastic products because of its heat resistance, flexibility, tensile strength, and texturability. It is now generally recognized that longterm and excessive inhalation of asbestos dust causes asbestosis, lung cancer, malignant mesothelioma and malignancies in other organs such as cancer of gastrointestinal tract, leukemia, lymphoma. Although eighty thousand tons of asbestos has been annually consumed since 1979 in korea, it has not been reported asbestos and lung cancer by asbestos dust so far, while a case of mesothelioma was officially diagnosis as a occupational disease at 1993. We experienced firstly a case of asbestosis and lung cancer caused simultanously by occupational asbestos exposure 11 years, which was confirmed by chest x-ray, pulmonary function test, chest CT and HRCT, bronchoalveolar lavage, and gallium scan. And so We present a case of asbestosis, pleural effusion and lung cancer with a review literature.

• Journal of Soil and Groundwater Environment
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• 제9권1호
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• pp.12-27
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• 2004

The contamination pattern of indoor air was simulated when groundwater dissolving benzene was used for household activities. Indoor exposure scenario consisted of inhalation, ingestion, and dermal absorption. Physiologically based pharmacokinetic (PBPK) model was used to analyze how benzene exposed to human body was distributed in internal organs. Main exposure pathways contributing total internal dose were inhalation and ingestion while the contribution of dermal absorption was very small. Man showed higher exposure rate than woman due to his higher breath rate. For a short-term exposure, benzene concentration in venous blood of SPT, RPT and liver changed rapidly while slowly did in venous blood of adipose tissue at a low concentration. For a long-term exposure, woman accumulated about 2.1 times higher than man. Most of benzene exposed to human body was removed by exhalation and metabolism at lung and liver, respectively. For inhalation and ingestion, the benzene removals by exhalation were 69.8 and 48.4%, respectively. Relative importance of removal mechanism was different according to the inflow displacement of benzene. The results obtained from this study would help understand exposure, distribution, and removal phenomena and make plans for the reduction of the health risk associated with the contaminated groundwater by various organic compounds.

• Tuberculosis and Respiratory Diseases
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• 제85권2호
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• pp.185-194
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• 2022

Background: The Korea Interstitial Lung Disease Study Group has made a new nationwide idiopathic pulmonary fibrosis (IPF) registry because the routine clinical practice has changed due to new guidelines and newly developed antifibrotic agents in the recent decade. The aim of this study was to describe recent clinical characteristics of Korean IPF patients. Methods: Both newly diagnosed and following IPF patients diagnosed after the previous registry in 2008 were enrolled. Survival analysis was only conducted for patients diagnosed with IPF after 2016 because antifibrotic agents started to be covered by medical insurance of Korea in October 2015. Results: A total of 2,139 patients were analyzed. Their mean age at diagnosis was 67.4±9.3 years. Of these patients, 76.1% were males, 71.0% were ever-smokers, 14.4% were asymptomatic at the time of diagnosis, and 56.9% were at gender-age-physiology stage I. Occupational toxic material exposure was reported in 534 patients. The mean forced vital capacity was 74.6% and the diffusing capacity for carbon monoxide was 63.6%. Treatment with pirfenidone was increased over time: 62.4% of IPF patients were treated with pirfenidone initially. And 79.2% of patients were treated with antifiboritics for more than three months during the course of the disease since 2016. Old age, acute exacerbation, treatment without antifibrotics, and exposure to wood and stone dust were associated with higher mortality. Conclusion: In the recent Korean IPF registry, the percentage of IPF patients treated with antifibrotics was increased compared to that in the previous IPF registry. Old age, acute exacerbation, treatment without antifibrotics, and exposure to wood and stone dust were associated with higher mortality.

• The Journal of Internal Korean Medicine
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• 제22권4호
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• pp.765-772
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• 2001

Paraquat has been widely used as herbcide since 1960s. Paraquat played a great role in agriculture history and rescued many people from starvation. On the other hand, it also killed lots of people. Paraquat is so lethally toxic that most of them who taken it come to die, even small amounts of ingestions. Therefore many methods has been tried for treating Paraquat intoxication, but they're still in controversial. In this study, the author report a case of Paraquat intoxication by using 8 constitutional acupuncture therapy, diet and herbal medication. The result was relatively acceptable.