• Title, Summary, Keyword: Internal exposure

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Verification of Harmonization of Dose Assessment Results According to Internal Exposure Scenarios

  • Kim, Bong-Gi;Ha, Wi-Ho;Kwon, Tae-Eun;Lee, Jun-Ho;Jung, Kyu-Hwan
    • Journal of Radiation Protection and Research
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    • v.43 no.4
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    • pp.143-153
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    • 2018
  • Background: The determination of the amount of radionuclides and internal dose for the worker who may have intake of radionuclides results in a variation due to uncertainty of measurement data and ingestion information. As a result of this, it is possible that for the same internal exposure scenario assessors could make considerably different estimation of internal dose. In order to reduce this difference, internal exposure scenarios for nuclear facilities were developed, and intercomparison were made to determine the harmonization of dose assessment results among the assessors. Materials and Methods: Seven cases on internal exposures incidents that have occurred or may occur were prepared by referring to the intercomparison excercise scenario that NRC and IAEA have carried out. Based on this, 16 nuclear facilities concerned with internal exposure in Korea were asked to evaluate the scenarios. Each result was statistically determined according to the harmonization discrimination criteria developed by IDEAS/IAEA. Results and Discussion: The results were evaluated as having no outliers in all 7 cases. However, the distribution of the results was spread by various causes. They can be divided into two wide categories. The first one is the distribution of the results according to the assumption of the intake factors and the evaluation factors. The second one is distribution due to misapplication of calculation method and factors related to internal exposure. Conclusion: In order to satisfy the harmonization criteria and accuracy of the internal exposure dose evaluation, it is necessary that exact guidelines should be set on low dose, and various intercomparison cases also be needed including high dose exposure as well as the specialized education. The aim of the blind test is to make harmonization evaluation, but it will also contribute to securing the expertise and high quality of dose evaluation data through the discussion among the participants.

A study on characteristics and internal exposure evaluation of radioactive aerosols during pipe cutting in decommissioning of nuclear power plant

  • Kim, Sun Il;Lee, Hak Yun;Song, Jong Soon
    • Nuclear Engineering and Technology
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    • v.50 no.7
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    • pp.1088-1098
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    • 2018
  • Kori unit #1, which is the first commercial nuclear power plant in Korea, was permanently shutdown in June 2017, and it is about to be decommissioned. Currently in Korea, researches on the decommissioning technology are actively conducted, but there are few researches on workers internal exposure to radioactive aerosol that is generated in the process of decommissioning nuclear power plants. As a result, the over-exposure of decommissioning workers is feared, and the optimal working time needs to be revised in consideration of radioactive aerosol. This study investigated the annual exposure limits of various countries, which can be used as an indicator in evaluating workers' internal exposure to radioactive aerosol during pipe cutting in the process of decommissioning nuclear power plants, and the growth and dynamics of aerosol. Also, to evaluate it, the authors compared/analyzed the cases of aerosol generated when activated pipes are cut in the process of nuclear power plants and the codes for evaluating internal exposure. The evaluation codes and analyzed data conform to ALARA, and they are believed to be used as an important indicator in deriving an optimal working time that does not excess the annual exposure limit.

DEVELOPMENT OF THE DUAL COUNTING AND INTERNAL DOSE ASSESSMENT METHOD FOR CARBON-14 AT NUCLEAR POWER PLANTS

  • Kim, Hee-Geun;Kong, Tae-Young;Han, Sang-Jun;Lee, Goung-Jin
    • Journal of Radiation Protection and Research
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    • v.34 no.2
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    • pp.55-64
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    • 2009
  • In a pressurized heavy water reactor (PHWR), radiation workers who have access to radiation controlled areas submit their urine samples to health physicists periodically; internal radiation exposure is evaluated by the monitoring of these urine samples. Internal radiation exposure at PHWRs accounts for approximately 20 $\sim$ 40% of total radiation exposure; most internal radiation exposure is attributed to tritium. Carbon-14 is not a dominant nuclide in the radiation exposure of workers, but it is one potential nuclide to be necessarily monitored. Carbon-14 is a low energy beta emitter and passes relatively easily into the body of workers by inhalation because its dominant chemical form is radioactive carbon dioxide ($^{14}CO_2$). Most inhaled carbon-14 is rapidly exhaled from the worker's body, but a small amount of carbon-14 remains inside the body and is excreted by urine. In this study, a method for dual analysis of tritium and carbon-14 in urine samples of workers at nuclear power plants is developed and a method for internal dose assessment using its excretion rate result is established. As a result of the developed dual analysis of tritium and carbon-14 in urine samples of radiation workers who entered the high radiation field area at a PHWR, it was found that internal exposure to carbon-14 is unlikely to occur. In addition, through the urine counting results of radiation workers who participated in the open process of steam generators, it was found that the likelihood of internal exposure to either tritium or carbon-14 is extremely low at pressurized water reactors (PWRs).

Urine Cotinine for Assessing Tobacco Smoke Exposure in Korean: Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES)

  • Jung, Sungmo;Lee, In Seon;Kim, Sae Byol;Moon, Chan Soo;Jung, Ji Ye;Kang, Young Ae;Park, Moo Suk;Kim, Young Sam;Kim, Se Kyu;Chang, Joon;Kim, Eun Young
    • Tuberculosis and Respiratory Diseases
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    • v.73 no.4
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    • pp.210-218
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    • 2012
  • Background: The level of urine cotinine is an indicator of tobacco smoke exposure. The purpose of this study is to investigate urine cotinine for the purpose of assessing the smoking status of Korean smokers and non-smokers exposed to tobacco smoke. Methods: The subjects were identified from the 2007-2009 and the 2010 data sets of the Korea National Health and Nutrition Examination Survey (KNHANES). They were assigned as non-smokers, current smokers and ex-smokers. Non-smokers were also divided into three subset groups according to the duration of smoke exposure. Each group was stratified by gender prior to analysis. Results: The median value of urine cotinine in the male current smokers was 1,221.93 ng/mL which was the highest among all groups. The difference between levels of urine cotinine for male and the female groups was statistically significant (p<0.01). In the female group, passive smoke exposure groups reported higher urine cotinine levels than non-exposure groups (p=0.01). The cutoff point for the discrimination of current smokers from non-smokers was 95.6 ng/mL in males and 96.8 ng/mL in females. The sensitivity and specificity were 95.2% and 97.1%, respectively, in males, 96.1% and 96.5% in females. However, the determination of urine cotinine level was not useful in distinguishing between passive smoke exposure groups and non-exposure groups. Conclusion: Urine cotinine concentration is a useful biomarker for discriminating non-smokers from current smokers. However, careful interpretation is necessary for assessing passive smoke exposure by urine cotinine concentration.

A Case of Acute Respiratory Failure After Trichloroethylene Inhalation (트리클로로에틸렌 흡입으로 인한 호흡부전 1례)

  • Park, Jae-Seok;Jeon, Young-Woo;Kim, Young-Il;Gil, Hyo-Wook;Yang, Jong-Oh;Lee, Eun-Young;Hong, Sae-Yong
    • Journal of The Korean Society of Clinical Toxicology
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    • v.9 no.1
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    • pp.30-33
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    • 2011
  • Trichloroethylene (TCE, $C_2HCl_3$), which was introduced as a gas for general anesthesia and analgesia in early 1900's has been widely used in industry as an organic solvent. Occupational exposure to TCE is an important medical problem. Manifestations of acute exposure to TCE include mucocutaneous irritation, hepatotoxicity, cognitive impairment, sleep, headache, respiratory insufficiency and death. We report a 38-year-old man who was admitted to a department of emergency medicine after occupational inhalation exposure to TCE. He rapidly developed semicoma and respiratory depression. After mechanical ventilation, hypercapnea and hypoxemia disappeared and his mental state again became alert. Careful evaluation and proper respiratory support are important for respiratory failure after occupational TCE inhalation.

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Does Sunlight Exposure Improve Survival in Patients with Non-small Cell Lung Cancer?

  • Mutlu, Hasan;Buyukcelik, Abdullah;Aksahin, Arzu;Kibar, Mustafa;Cihan, Yasemin Benderli;Kaya, Eser;Seyrek, Ertugrul;Yavuz, Sinan;Erden, Abdulsamet;Calikusu, Zuleyha;Aslan, Tuncay;Akca, Zeki
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6301-6304
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    • 2013
  • Background: Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer. Materials and Methods: A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively. Results: The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880). Conclusions: There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.

Influence of Environmental Exposures on Patients with Chronic Obstructive Pulmonary Disease in Korea

  • Hong, Yoonki;Lim, Myoung Nam;Kim, Woo Jin;Rhee, Chin Kook;Yoo, Kwang Ha;Lee, Ji-Hyun;Yoon, Ho Il;Kim, Tae-Hyung;Lee, Jin Hwa;Lim, Seong Yong;Lee, Sang Do;Oh, Yeon-Mok
    • Tuberculosis and Respiratory Diseases
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    • v.76 no.5
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    • pp.226-232
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    • 2014
  • Background: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation and results from environmental factors and genetic factors. Although cigarette smoking is a major risk factor, other environmental exposures can influence COPD. The purpose of this study is to investigate the clinical characteristics of COPD according to the history of environmental exposure. Methods: The study population comprised of 347 subjects with COPD who were recruited from the pulmonary clinics of 14 hospitals within the Korean Obstructive Lung Disease Study Group. We classified environmental exposures according to history of living near factory, and direct exposure history to firewood or briquette. According to living environmental exposures, we compared the frequency of respiratory symptoms, pulmonary function, quality of life, exercise capacity, and computed tomography phenotypes. Results: Thirty-one subjects (8.9%) had history of living near factory, 271 (78.3%) had exposure history to briquette, and 184 (53.3%) had exposure history to firewood. Patients with history of living near a factory had a significantly longer duration of sputum, while patients with exposure to firewood tended to have lower forced expiratory volume in one second, and patients with exposure to briquette tended to have lower six minute walk distance. Conclusion: COPD subjects with the history of living near factory had more frequent respiratory symptoms such as sputum. Our data suggest that environmental exposure may influence clinical phenotype of COPD.

The Inflammatory Response in Mouse Lung after Acute Sulfur Dioxide Exposure (급성 아황산가스 폭로후 흰쥐의 폐에 유발된 염증반응에 관한 연구)

  • Chin, Young-Joo;Park, Nam-Gyu;Lee, Hyeon-Suk;Kim, Dae-Soo;Earm, Jae-Ho;Cho, Myeong-Chan;Yoon, Sei-Jin;Jeong, Hwa-Sook;Song, Hyung-Geun;Sung, Ro-Hyun;Lee, Sang-Do
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.4
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    • pp.328-338
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    • 1994
  • Background: Effect of sulfur dioxide($SO_2$) exposure on airway is well known but little about the effect of $SO_2$ exposure on lung parenchyme. This study is to determine if short tenn exposure to $SO_2$ in concentration commonly found in industrialized environment cause potentially harmful effect on the lung parenchyme, and to evaluate the exposure time-response relationship between short tenn exposure to $SO_2$ and the inflammatory response in mouse lung. Method: 5ppm $SO_2$ gas was used and 48 mice were grouped into control(10), 30(9), 60(11), and 120 minute exposure(18) group. In each group, bronchoalveolar lavage(BAL) was done immediately after and at 1,2,3 days after exposure. Histological examination was performed in control and 120 minute exposure group. Results: 1) Cell response in bronchoalveolar lavage fluid. In 30 and 60 minute exposure group, compared to the control group, lymphocyte count has significantly increased(p<0.05) at 1 day after exposure but did not differ at 2 days after exposure. In 120 minute exposure group, also compared to the control group, there was significant increase in total cell, macrophage, and lymphocyte count at 1 day after exposure, (p<0.05) which lasted for 2 days but did not significantly differ at 3 days after exposure. 2) Histological findings in 120 minute exposure group. In the airway, mild epithelial cell damage and ciliary loss were noted but there was no evidence of inflammatory cell infiltration. Interstitial inflammatory infiltration was noted at 1 day after exposure, which lasted for 3 days after exposure and there was no evidence of edema or fibrosis in the interstitium Conclusions: These data indicate potentially noxious effect of $SO_2$ on the lung parenchyme as well as the airway at exposure level that are regarded as relatively safe, and the duration of injury depends on the exposure time.

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Assessment of Fluoride Exposure by Oral Health Behaviors using the ConsExpo Model (ConsExpo 모델을 이용한 구강건강행위에 따른 불소노출평가)

  • Oh, Na-Rae;Jeong, Mi-Ae
    • The Journal of the Korea Contents Association
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    • v.17 no.7
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    • pp.498-504
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    • 2017
  • Oral health behavior such as toothbrushing one's teeth, using dentifrice and such are an important part of improving one's oral health and therefore quality of life. However, it is also necessary to research exposure to harmful chemical substances. Therefore, this study investigated the factors that affect researching fluorine exposure resulting from oral health behavior initiation so that correct oral health guidelines can be provided. As a result of applying the fluorine compound's oral exposure in the ConsExpo 5.0 model, adult males' oral external dose was at 0.000196 mg/kg, oral acute (internal) dose at 0.000196 mg/kg/day and oral chronic (internal) dose at 0.000465 mg/kg/day. In the case of females, the oral dose was at $4.1{\times}10^{-6}mg/kg$, oral acute (internal) dose at $4.1{\times}10^{-6}mg/kg$ and oral chronic (internal) dose at $9.99{\times}10^{-6}mg/kg/day$.