• Title/Summary/Keyword: Internal exposure

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Internal Dosimetry: State of the Art and Research Needed

  • Francois Paquet
    • Journal of Radiation Protection and Research
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    • v.47 no.4
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    • pp.181-194
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    • 2022
  • Internal dosimetry is a discipline which brings together a set of knowledge, tools and procedures for calculating the dose received after incorporation of radionuclides into the body. Several steps are necessary to calculate the committed effective dose (CED) for workers or members of the public. Each step uses the best available knowledge in the field of radionuclide biokinetics, energy deposition in organs and tissues, the efficiency of radiation to cause a stochastic effect, or in the contributions of individual organs and tissues to overall detriment from radiation. In all these fields, knowledge is abundant and supported by many works initiated several decades ago. That makes the CED a very robust quantity, representing exposure for reference persons in reference situation of exposure and to be used for optimization and assessment of compliance with dose limits. However, the CED suffers from certain limitations, accepted by the International Commission on Radiological Protection (ICRP) for reasons of simplification. Some of its limitations deserve to be overcome and the ICRP is continuously working on this. Beyond the efforts to make the CED an even more reliable and precise tool, there is an increasing demand for personalized dosimetry, particularly in the medical field. To respond to this demand, currently available tools in dosimetry can be adjusted. However, this would require coupling these efforts with a better assessment of the individual risk, which would then have to consider the physiology of the persons concerned but also their lifestyle and medical history. Dosimetry and risk assessment are closely linked and can only be developed in parallel. This paper presents the state of the art of internal dosimetry knowledge and the limitations to be overcome both to make the CED more precise and to develop other dosimetric quantities, which would make it possible to better approximate the individual dose.

A Case of Accelerated Silicosis Mimicking Miliary Pulmonary Tuberculosis (속립성 결핵과 감별이 필요했던 가속형 규폐증 1례)

  • Kim, Kwang Hyun;Kim, Sang-Ha;Kwon, Woo Cheol;Lee, Myong Kyu;Choi, Hoon;Lee, Nak Won;Hong, Tae Won;Yong, Suk Joong;Shin, Kye Chul;Jung, Soon Hee;Lee, Won Yeon
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.6
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    • pp.684-689
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    • 2005
  • Silicosis is a chronic fibrosing lung disease that is initiated by prolonged and extensive exposure to respirable free crystalline silica. Accelerated silicosis is rare and is clinically identical to the classic form of silicosis with the exception that the time from initial exposure to the onset of the disease is shorter and the rate of disease progression is dramatically faster. We describe a case of accelerated silicosis, which mimicked miliary pulmonary tuberculosis. The patient had worked in a mine coal for a period of 9 years. Subsequently, he worked in construction dealing with cement and sand for 14 years until he visited this clinic. The clinical course was notable for the rapid progression of the radiological features of silicosis over a period of 2 months. Polarizing light microscopic studies of the biopsied specimens by a transbronchial lung biopsy showed polarizing particles, which were typical of silica. To the best of our knowledge, this is the first case report of accelerated silicosis in Korea.

Severe Acute Fibrinous and Organizing Pneumonia with Acute Respiratory Distress Syndrome

  • Kang, Hyo-Jae;Choi, Sun-Mi;Jeong, Yun-Jeong;Park, Jong-Sun;Lee, Sei-Won;Yoon, Ho-Il;Lee, Jae-Ho;Lee, Choon-Tack;Cho, Young-Jae
    • Tuberculosis and Respiratory Diseases
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    • v.71 no.5
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    • pp.368-372
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    • 2011
  • Acute fibrinous and organizing pneumonia is a newly recognized pattern of acute lung injury. A 49-year-old female presented with a cough and worsening dyspnea on exertion. She had no history of smoking and no specific past medical history except exposure of home humidifier containing sterilizer. A chest computed tomography scan showed patchy consolidation with fibrosis in the right lower lobe and ill-defined centrilobular ground glass opacity in both lungs. The pathological findings were patchy areas of lung parenchyma with fibrin deposits in the alveolar ducts and alveoli, and fibrin balls with hemosiderin deposition in the alveolar spaces. The histological pattern of our case is differentiated from diffuse alveolar damage by the absence of hyaline membranes, and from eosinophilic pneumonia by the lack of eosinophils. In our case, the patient was treated with corticosteroid pulse therapy. However, the clinical course became aggravated and she died within two weeks.

The Effects of Mycobacterium Tuberculosis on Alveolar Macrophages -The Alterations of Superoxide Production in both Human and Rat Alveolar Macrophages Exposed to Mycobacterium Tuberculosis H37Ra Strain- (결핵균이 폐포대식세포의 기능에 미치는 영향에 관한 연구 -H37Ra 결핵균종에 의한 사람 몇 백서 폐포대식세포의 Superoxide 생성의 변화-)

  • Kim, Keon-Youl;Lee, Kye-Young;Hyun, In-Kyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.39 no.6
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    • pp.526-535
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    • 1992
  • Background: The oxygen radicals released by alveolar macrophages contribute to killing of microorganisms including M. tuberculosis. Macrophages are "primrd" for enhanced oxygen radical release by macrophage activator like IFN-$\gamma$ and LPS, which do not themselves cause release of oxygen radicals. Actural production of oxygen radicals is "triggered" by phagocytosis or by exposure to chemical stimuli like PMA or FMLP. There has been debates about the priming effect of alveolar macro phages because they are exposed to usual environmental particles unlike blood monocytes. Therefore we examined priming effect of IFN-$\gamma$ in human alveolar macrophages comparing with that in blood monocytes and rat alveolar macrophages. And we observed the alterations of superoxide production in both human and rat alveolar macrophages after exposure to M. tuberculosis H37Ra bacilli itself and its lysate. Methods: Bronchoalveolar lavage fluid was processed to isolate alveolar macrophages by adherence and the adherent cells were removed by cold shock method. After exposure to M. tuberculosis H37Ra strain, alveolar macrophages were incubated for 24 hours with IFN-$\gamma$. The amount of superoxide production stimulated with PMA was measured by ferricytochrome C reduction method. Results: 1) The priming effect in human alveolar macrophages was not observed even with high concentration of IFN-$\gamma$ while it was observed in blood monocytes and rat alveolar macrophages. 2) Both human and rat alveolar macrophages exposed to avirulent H37Ra strain showed triggering of superoxide release and similar results were shown with the exposure to H37Ra lysate. Conclusion: The priming effect in human alveolar macrophages is not observed because of its usual exposure to environmental particles and avirulent H37Ra strain does not inhibit the activation of alveolar macrophages.

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Towards Quantitative Assessment of Human Exposures to Indoor Radon Pollution from Groundwater

  • Donghan Yu;Lee, Han-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.E2
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    • pp.43-51
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    • 2001
  • A report by the national research council in the United States suggested that many lung cancer deaths each year be associated with breathing radon in indoor air. Most of the indoor radon comes directly from soil beneath the basement of foundations. Recently, radon released from groundwater is found to contribute to the total inhalation risk from indoor air. This study presents the quantitative assessment of human exposures to radon released from the groundwater into indoor air. At first, a three-compartment model is developed to describe the transfer and distribution of radon released from groundwater in a house through showering, washing clothes, and flushing toilets. Then, to estimate a daily human exposure through inhalation of such radon for an adult. a physiologically-based pharmacokinetic(PBPK) model is developed. The use of a PBPK model for the inhaled radon could provide useful information regarding the distribution of radon among the organs of the human body. Indoor exposure patterns as input to the PBPK model are a more realistic situation associated with indoor radon pollution generated from a three-compartment model describing volatilization of radon from domestic water into household air. Combining the two models for inhaled radon in indoor air can be used to estimate a quantitative human exposure through the inhalation of indoor radon for adults based on two sets of exposure scenarios. The results obtained from the present study would help increase the quantitative understanding of risk assessment issues associated with the indoor radon released from groundwater.

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A Study on the Priority for the Hazard and Risk Evaluation of Chemicals (HREC) According to the Industrial Safety and Health Act (ISHA) (산업안전보건법 상 관리수준 검토를 위한 화학물질 유해성.위험성 평가대상 후보물질 선정에 관한 연구)

  • Yang, Jeong Sun;Lim, Cheol Hong;Park, Sang Young
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.22 no.1
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    • pp.73-81
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    • 2012
  • Object: The aim of this study is to suggest a list of priority chemicals for the Hazard & Risk Evaluation of Chemicals (HREC) controlled by the Industrial Safety and Health Act (ISHA). Method: Screening assessment was done for 642 chemicals whose exposure threshold limit values were set by the Ministry of Employment and Labor (MOEL). Hazard data were collected from Korea Occupational Safety & Health Agency (KOSHA) and/or other toxicity database. Exposure data were obtained from KOSHA internal database. The hazard and exposure scores of chemicals were listed by order of priority in accordance with GHS classification and exposure index data. Result: From the result of screening risk assessment for 642 chemicals, we extracted a list of 13 priority chemicals for HREC performed by the ISHA. A priority list of 27 chemicals which have carcinogen, mutagen and/or reproductive toxicity but not controlled by the ISHA was suggested for additional evaluation as "chemicals for special management".

Identification and Application of Biomarkers in Molecular and Genomic Epidemiologic Research

  • Lee, Kyoung-Mu;Han, So-Hee;Park, Woong-Yang;Kang, Dae-Hee
    • Journal of Preventive Medicine and Public Health
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    • v.42 no.6
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    • pp.349-355
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    • 2009
  • Biomarkers are characteristic biological properties that can be detected and measured in a variety of biological matrices in the human body, including the blood and tissue, to give an indication of whether there is a threat of disease, if a disease already exists, or how such a disease may develop in an individual case. Along the continuum from exposure to clinical disease and progression, exposure, internal dose, biologically effective dose, early biological effect, altered structure and/or function, clinical disease, and disease progression can potentially be observed and quantified using biomarkers. While the traditional discovery of biomarkers has been a slow process, the advent of molecular and genomic medicine has resulted in explosive growth in the discovery of new biomarkers. In this review, issues in evaluating biomarkers will be discussed and the biomarkers of environmental exposure, early biologic effect, and susceptibility identified and validated in epidemiological studies will be summarized. The spectrum of genomic approaches currently used to identify and apply biomarkers and strategies to validate genomic biomarkers will also be discussed.

African-American Hair Damage Study

  • Tang, Diana
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.413-416
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    • 2003
  • Hair fragility is a major concern to most people of African decent due to frequent chemical treatments, thermal appliance use and environmental exposure. It is extremely important to both cosmetic scientists and African-American consumers to understand the internal and external hair damage caused by these factors.(omitted)

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A Case of Pulmonary Siderosis Confirmed by Bronchoalveolar Lavage and Transbronchial Lung Biopsy (기관지 폐포 세척술 및 경피적 폐 생검술로 확진된 철폐증 1례)

  • Kim, Eun A;Bang, Byoung Uk;Kim, Lucia;Ryu, Jeon Seon;Kwak, Seung Min;Lee, Hong Lyeol;Cho, Jae Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.5
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    • pp.476-479
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    • 2004
  • Pulmonary siderosis is one kind of pneumoconiosis, occurs from chronic inhalation of iron or iron oxide. Inhaled iron dust is deposited in the intra-alveolar spaces, which leads to radiological changes and respiratory symptoms. It is diagnosed by iron exposure history, radiological changes, and the evidence of intra-alveolar iron deposit. We have experienced a case of pulmonary siderosis which was confirmed by bronchoalveolar lavage and transbronchial lung biopsy, so report it with a review of literature.