• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.667-674
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• 2019

Because examination with technegas produces images through simple diffusion accumulation, the examination room can become contaminated after scan. Therefore, radiation workers and patients awaiting examination will be affected by internal exposure from technegas inhalation. Before and after gravity ventilation, I am trying to find a way to reduce the exposure dose of waiting patients according to a comparative analysis of horizontal spatial dose rates over time. Spatial dose ratio were measured for 10 minutes from various distances and angles around ventilator's location before and after gravity ventilation. Then, mean values, standard deviation and reduction ratio were calculated. The highest reduction rate of gravity ventilation was 95.31% and the highest reduction ratio was 1 to 3 minutes. Therefore, the gravity ventilation could reduce the exposure dose of radiologic technologists, waiting patients, patient guardians and nurses. In conclusion, the reduction of the exposure dose during the technegas ventilation study through gravity ventilation will play a role in optimiging the protection and it is in accordance with the recommended reduction of the medical exposure by ICRP 103.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.11-15
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• 2000

Purpose: The primary objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with an Orthopos plus, a Panelipse, and a Panex-E machines. The second objective was to compare the absorbed doses between 5 inch by 12 inch and 6 inch by 12 inch image field for the Orthopos plus. Materials and Methods: Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor, the maxillary sinus, the brain, the mandibular body, the mandibular ramus, the 2nd cervical spine and the skin over TMJ area. Results: The highest absorbed dose value was recorded at the mandibular ramus for the Orthopos plus with narrow image field. Higher absorbed dose values were recorded at the parotid gland, the mouth floor, the submandibular gland, and the 2nd cervical spine. The doses in the parotid gland were 597 μGy and 529 μGy with Orthopos plus, 638 μGy with Panelipse, and 1094μGy with Panex-E. Corresponding figures for the mandibular ramus were 2363 Gy and 1220 μGy, 248 μGy, and 118 μGy. The absorbed doses to the thyroid gland, the maxillary sinus, the brain, and the skin over TMJ were very low. Conclusion: Higher exposure values were recorded for the Orthopos plus than Panelipse and Panex-E. There was no significant differences of the absorbed doses according to the image field size.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.101-106
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• 1984

Various methods are available for determination of exposure time in intracavitary radiotherapy of the carcinoma of the uterine cervix. To determine the accuracy of dose calculation with isodose curve for TAO applicator, comparison with results calculated by computer for radiotherapy treatment Planning was done in 24 procedures done in 12 consecutive patients with the carcinoma of the uterine cervix from May to December, 1983. The results are as follows: 1. The average dose rate Per hour of Point A was 87.70 rad, being 89.91 rad ana 85.49 rad in left and right, respectively. 2. The average percentage of dose rate of point A calculated by isodose curve method over that by computer was $101.28\%$ and the difference was less than $5\%$ in 17 Procedures and over $10\%$ in only 3 procedures. 3. The average percentage in case of point B was $108.67\%$. In conclusion, in most cases the difference was less than 200 rad for point A and less than 100 rad for point B during 2 courses of intracavitary radiotherapy. And so the dose rate calculation with isodose curve for TAO applicator is comparatively accurate.

• Journal of Microbiology and Biotechnology
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• v.17 no.3
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• pp.398-402
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• 2007

Abstract Female mice post weaning were exposed to 20 kHz sawtooth electric and magnetic fields (EMF) with $6.25{\mu}T$ peak intensity for 6 weeks. Estrous cycles were checked using vaginal smears over the last 10 days of the experimental period. The vaginal smears from EMF-exposed mice revealed an increase in the frequency of one or two phases persisting. The number of estrous cycles less than 1 was more in the EMF-exposed group than in the sham control group. Furthermore, in the EMF-exposed group, the duration of proestrous and metestrous stages of the estrous cycle was significantly increased compared with the control group. In conclusion, our results suggest that exposure to 20 kHz sawtooth EMF may affect normal cycling of the estrous cycle by disrupting the female reproductive endocrine physiology. We should not disregard the possible adverse reproductive effect of the 20 kHz sawtooth EMF generated under the occupational exposure situation in females.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.157-170
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• 2008

Purpose: This prospective study was conducted to reveal the haematological index change by low level radiation exposure in radiological environment our hospital workers. Materials and Method: We gathered the cumulative dose by Thermoluminenscent Dosimeters (TLD) over 9-yr period and examined hematological index counts change (RBC, Hb, Platelet, WBC, Monocyte, Lymphocyte, Neutrophilic, Basophilic, Eosinophilic) both occupational workers and controls. Of a total 370 occupational workers and 335 controls were compared. Results: This analysis has led to the following general observations 1) The average cumulative dose in male and female were $9.65{\pm}15.2\;mSv$, $4.82{\pm}5.55\;mSv$ respectively. 2) In both male and female, there were very low relationship between occupation period and cumulative dose (r< ${\pm}0.25$). 3) Occupation period was more increased, in male, WBC counts decreased and increased workers, RBC counts decreased workers were more than controls group (p<0.05). In female, WBC counts decreased and increased workers and W-eosino counts decreased workers were more than controls group (p<0.01). 4) Cumulative dose was more increased, in male, W-Lympho counts decreased workers and Platelet counts deceased workers were more than controls group (p<0.05). In female, W-lympho counts decreased workers and RBC counts decreased workers were more than controls group (p<0.05). Conclusions: We can find some kinds of blood index abnormal distribution in occupational radiation workers by comparing with controls. Occupational workers cannot avoid radiation exposure, in spite of the control it. Actually low level radiation adverse effect occurred not dose but probability. So workers must always try to reduce exposure by ourselves, furthermore as long as possible the government should provide rapidly that national system on radiation control for worker's health.

• Journal of Pharmacopuncture
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• v.20 no.2
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• pp.107-111
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• 2017

Objectives: Radiation is one of the most important sources of free radical (such as reactive oxygen species) production, which plays an essential role in the etiology of over hundred diseases. The aim of the study was to investigate some immune parameters and hematological indices in healthy workers of the Radiology Department, University Hospital of Mashhad, Iran. Methods: The study was performed on 50 healthy workers: 30 radiology staff as the case group and 20 laboratory workers as the control group. The radiation dose received by the radiology staff participating in the study was less than the annual maximum permissible level, 50 millisievert. Hematological parameters, lymphocyte proliferation and cytokine production were studied in both groups. Results: Among healthy radiology workers, the hematological indices did not differ statistically; however, their proliferation indices and $IFN-{\gamma}$ levels showed significant increases in parallel with decreases in the IL-4 levels as compared to controls. The immune system of workers exposed to low-dose ionizing radiation was found to be shifted from a Type 2 to a Type 1 response to promote cellular immunity. Conclusion: Based on our data, exposure to low-dose ionizing radiation may decrease the prevalence, frequency, and recurrence of various cancers and infectious diseases because of an increase in Th1-cell-based response, thus leading to more protection of the human body against tumor cells and foreign agents and possibly increased longevity. However, due to high rate of fluoroscopy use for interventional radiology, we suggest continuing research projects on radiation protection and hazards to prevent irreversible damage. As a recommendation, in future studies, radiology staff with a weakened immunity due to high radiation exposure should be considered as good choices to be treated using acupuncture techniques because acupuncture has been demonstrated to enhance the function and the number of immune cells.

• Imaging Science in Dentistry
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• v.31 no.4
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• pp.215-219
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• 2001

Purpose: The objective of this study was to estimate the radiation absorbed doses in certain critical organs in the head and neck region with 16 imaging programs available on the Orthopos/sup (R)/ panoramic machine. Materials and Methods: A Rando phantom and LiF TLD chips were used for dosimetry. The absorbed doses were measured at the thyroid gland, the submandibular gland, the parotid gland, the mouth floor. the maxillary sinus, the brain, the mandibular body, the mandibular ramus. the 2nd cervical spine and the skin over TMJ area. Results : The overall absorbed doses with imaging programs available on the Orthopos/sup (R)/ panoramic machine were much less than that of standard program (program 1) except program 8, 11, and 16. Generally, the absorbed doses to the bone marrow of the mandibular ramus and the parotid gland were high, but the absorbed doses to the bone marrow in the mandibular body, brain, maxillary sinus, and, especially, the thyroid gland were very low. Conclusion : The modified imaging programs available on the Orthopos/sup (R)/ panoramic machine can be effectively used in aspect of radiation protection.

• Journal of radiological science and technology
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• v.43 no.5
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• pp.389-395
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• 2020

The evaluation of radioactivated components of heavy-ion accelerator facilities affects the safety of radiation management and the exposure dose for workers. and this is an important issue when predicting the disposal cost of waste during maintenance and dismantling of accelerator facilities. In this study, the FLUKA code was used to simulate the proton treatment device nozzle and classify the radio-nuclides and total radioactivity generated by each component over a short period of time. The source term was evaluated using NIST reference beam data, and the neutron flux generated for each component was calculated using the evaluated beam data. Radioactive isotopes caused by generated neutrons were compared and evaluated using nuclide information from the International Radiation Protection Association and the Korea Radioisotope association. Most of the nuclides produced form of beta rays and electron capture, and short-lived nuclides dominated. However, In the case of ⁵⁴Mn, which is a radioactive product of iron, the effect of gamma rays should be considered. In the case of tritium generated from a material with a low atomic number, it is considered that handling care should be taken due to its long half-life.

• Journal of Environmental Health Sciences
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• v.50 no.1
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• pp.1-5
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• 2024

International Commission on Radiological Protection (ICRP) is an independent international organization that advances the science of radiological protection for the public benefit, particularly by providing recommendations and guidance on all aspects of protection against ionizing radiation. The ICRP is a community of more than 380 globally-recognized experts in radiological protection science, policy, and practice from more than 50 countries. As of January 2024, the ICRP is comprised of a Main Commission, the Scientific Secretariat, four Standing Committees, and 30 Task Groups under the four committees. The ICRP has released well over one hundred publications on all aspects of radiological protection. Most address a particular area within radiological protection, but a handful of the publications, the so-called fundamental recommendations, describe the overall system of radiological protection. The system for radiological protection is based on the current understanding of the science of radiation exposure and its effects along with value judgements. The ICRP offers recommendations to regulatory and advisory agencies and provides advice to management and professional staff with responsibilities for radiological protection. Legislation in most countries adheres closely to ICRP recommendations. The International Atomic Energy Agency's (IAEA) International Basic Safety Standards are based heavily on ICRP recommendations. ICRP recommendations form the core of radiological protection standards, legislation, programs, and practice worldwide.

• Journal of Astronomy and Space Sciences
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• v.31 no.1
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• pp.25-31
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• 2014

There has been a rapid increase of the concern on the space radiation effect on pilots, crew and passengers at the commercial aircraft altitude (~ 10 km) recently. It is because domestic airline companies, Korean Air and Asiana Airlines have just begun operating the polar routes over the North Pole since 2006 and 2009 respectively. CARI-6 and CARI-6M are commonly used space radiation estimation programs which are provided officially by the U.S. federal aviation administration (FAA). In this paper, the route doses and the annual radiation doses for Korean pilots and cabin crew were estimated by using CARI-6M based on 2012 flight records. Also the modeling concept was developed for our own space radiation estimation program which is composed of GEANT4 and NRLMSIS00 models. The GEANT4 model is used to trace the incident particle transports in the atmosphere and the NRLMSIS00 model is used to get the background atmospheric densities of various neutral atoms at the aircraft altitude. Also presented are the results of simple integration tests of those models and the plan to include the space weather variations through the solar proton event (SPE) prediction model such as UMASEP and the galactic cosmic ray (GCR) prediction model such as Badhwar-O'Neill 2010.