• Title/Summary/Keyword: internal exposure

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Chronic Cadmium Intoxication and Renal Injury Among Workers of a Small-scale Silver Soldering Company

  • Choi, Won-Jun;Kang, Seong-Kyu;Ham, Seunghon;Chung, Wookyung;Kim, Ae Jin;Kang, Myunghee
    • Safety and Health at Work
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    • v.11 no.2
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    • pp.235-240
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    • 2020
  • Background: Cadmium exposure may induce chronic intoxication with renal damage. Silver soldering may be a source of cadmium exposure. Methods: We analyzed working environment measurement data and periodic health screening data from a small-scale silver soldering company with ten workers. Concentrations of cadmium in air from working environment measurement data were obtained. Concentrations of blood and urinary cadmium, urine protein, and urine β2-microglobulin (β2M) were obtained. The generalized linear model was used to identify the association between blood and urine cadmium and urine β2M concentrations. Clinical features of chronic cadmium intoxication focused with toxicological renal effects were described. Results: The mean duration of work was 8.5 years (standard deviation [SD] = 6.9, range = 3-20 years). Cadmium concentrations in air were ranged from 0.006 to 0.015 mg/㎥. Blood cadmium concentration was elevated in all ten workers, with a highest level of 34.6 ㎍/L (mean = 21.288 ㎍/L, SD = 11.304, range = 9.641-34.630 ㎍/L). Urinary cadmium concentration was elevated in nine workers, with a highest level of 62.9 ㎍/g Cr (mean = 22.151 ㎍/g creatinine, SD = 19.889, range = 3.228-62.971 ㎍/g creatinine). Urine β2M concentration was elevated in three workers. Urinary cadmium concentration was positively associated with urine protein concentration (beta coefficient = 10.27, 95% confidence interval = [4.36, 16.18]). Other clinical parameters were compatible with renal tubular damage. Conclusion: Cadmium intoxication may occur at quite low air concentrations. Exposure limit may be needed to be lowered.

A Comprehensive Study for Two Damage Sites of Human Hair upon UV-B Damage

  • Song, Sang-Hun;Son, Seongkil;Kang, Nae Gyu
    • Korea Journal of Cosmetic Science
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    • v.2 no.1
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    • pp.1-10
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    • 2020
  • Protection mechanisms for skin damage of ultraviolet (UV) absorbers in personal care products for protection against UV are well studied, but not for hair protection. The purpose of this study is to describe and compare the changes of physical property produced in human hair by doses of the UV-B exposure causing protein degradation. To observe the change of physical properties in hair, the experimental intensity of UV-B exposure has been established on the basis of statistical data from official meterological administration as daily one hour sunlight exposure for two weeks. Polysilicone-15, ethylhexyl methoxycinnamate (OMC), and octocrylene were employed for UV-B absorber, and those were treated to hair swatch by rubbing wash through shampoo and conditioner. Bending rigidity displayed kinetically successive reduction at high doses of UV exposure up to the 8,000 s, and exhibited different level at each sample of UV-B absorber. However, the values of Bossa Nova Technologies (BNT) for shinning factor were already saturable at the 2,000 s exposure except that treated with polysilicone-15. The differential scanning calorimetry (DSC) to measure a strength of inner protein produces a successive reduction of enthalpy as like a reduction of bending rigidity upon UV exposure. Surface roughness from lateral force microscope (LFM) acquired immediately after UV exposure show a saturable frictional voltage which has been also found in a saturable BNT data as the time of UV exposure increases. Through researching the DSC and the LFM, shinning of hair was much correlated to the protein damage at the surface, and bending rigidity could be regulated by the protein structural damage inside hair. Therefore, the optimization of efficient strategy for simultaneous prevention of hair protein on the surface and internal hair was required to maintain physical properties against UV.

Application of Physiologically Based Pharmacokinetic Modeling with Biological Monitoring Data for Risk Assessment (생물학적 모니터링 데이터를 기초한 PBPK 모델의 활용)

  • Yang, Mi-Hi;Yang, Ji-Yeon;Yi, Bit-Na;Lee, Ho-Sun
    • Environmental Analysis Health and Toxicology
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    • v.22 no.1 s.56
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    • pp.1-8
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    • 2007
  • Biological monitoring, analyses of internal dose for exposure to toxicants, has been thought as one of the belt approaches for risk assessment. As the amount detected in human samples is generally very low, typically in the parts-per-bilion (ppb) or parts-per-trillion (ppt) range, analytic technologies such at HPLC, GC/MS, LC/MS, and LC/MS/MS have been continuously developed. In addition, route specific and sensitive exposure biomarkers have been developed for proper biological monitoring. PBPK modeling, particularly reverse dosimetry, has been emphasized as an useful method via interpretation of biological monitoring results for regulation of toxicants. Thus, this review is focused on the use of PBPK dosimetry models for toxicology research and risk assessment in Korea.

Assessment of Internal Radiation Dose Due to Inhalation of Particles by Workers in Coal-Fired Power Plants in Korea (국내 석탄화력발전소 내 작업종사자의 입자 흡입에 따른 내부피폭 방사선량 평가)

  • Do Yeon Lee;Yong Ho Jin;Min Woo Kwak;Ji Woo Kim;Kwang Pyo Kim
    • Journal of Radiation Industry
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    • v.17 no.2
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    • pp.161-172
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    • 2023
  • Coal-fired power plants handle large quantities of coal, one of the most prominent NORM, and the coal ash produced after the coal is burned can be tens of times more radioactive than the coal. Workers in these industries may be exposed to internal exposure by inhalation of particles while handling NORM. This study evaluated the size, concentration, particle shape and density, and radioactivity concentrations of airborne suspended particles in the main processes of a coal-fired power plant. Finally, the internal radiation dose to workers from particle inhalation was evaluated. For this purpose, airborne particles were collected by size using a multi-stage particle collector to determine the size, shape, and concentration of particles. Samples of coal and coal ash were collected to measure the density and radioactivity of particles. The dose conversion factor and annual radionuclide inhalation amount were derived based on the characteristics of the particles. Finally, the internal radiation dose due to particle inhalation was evaluated. Overall, the internal radiation dose to workers in the main processes of coalfired power plants A and B ranged from 1.47×10-5~1.12×10-3 mSv y-1. Due to the effect of dust generated during loading operations, the internal radiation dose of fly ash loading processes in both coal-fired power plants A and B was higher than that of other processes. In the case of workers in the coal storage yard at power plants A and B, the characteristic values such as particle size, airborne concentration, and working time were the same, but due to the difference in radioactivity concentration and density depending on the origin of the coal, the internal radiation dose by origin was different, and the highest was found when inhaling coal imported from Australia among the five origins. In addition, the main nuclide contributing the most to the internal radiation dose from the main processes in the coal-fired power plants was thorium due to differences in dose conversion factors. However, considering the external radiation dose of workers in coal-fired power plants presented in overseas research cases, the annual effective dose of workers in the main processes of power plants A and B does not exceed 1mSv y-1, which is the dose limit for the general public notified by the Nuclear Safety Act. The results of this study can be utilized to identify the internal exposure levels of workers in domestic coal-fired power plants and will contribute to the establishment of a data base for a differential safety management system for NORM-handling industries in the future.

Investigation of Internal Temperature and Relative Humidity of Concrete Immediately After Mix and Placement (양생직후 초기재령의 콘크리트 내부 온도와 상대습도의 측정 및 분석)

  • Park, Cheol-Woo;Park, Young-Hoon;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1065-1068
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    • 2008
  • Concrete is still one most common construction materials even in railway structures. As structures become massive and mega-sized, the importance of early age concrete quality control becomes more significant. Among various factors, relative humidity and temperature are the primary factors governing the early age quality. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.

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Korean-specific iodine S values for use in internal dosimetry

  • Tae-Eun Kwon;Yoonsun Chung;Choonsik Lee
    • Nuclear Engineering and Technology
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    • v.55 no.12
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    • pp.4659-4663
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    • 2023
  • The use of iodine S values derived using the International Commission Radiological Protection (ICRP) phantoms may introduce significant bias in internal dosimetry for Koreans due to anatomical variability. In the current study, we produced an extensive dataset of Korean S values for selected five iodine radioisotopes (I-125, I-129, I131, I-133, and I-134) for use in radiation protection. To calculate S values, we implemented Monte Carlo simulations using the Mesh-type Reference Korean Phantoms (MRKPs), developed in a high-quality/fidelity mesh format. Noticeable differences were observed in S value comparisons between the Korean and ICRP reference phantoms with ratios (Korean/ICRP) widely ranging from 0.16 to 6.2. The majority of S value ratios were lower than the unity in Korean phantoms (interquartile range = 0.47-1.28; mean = 0.96; median = 0.69). The S values provided in the current study will be extensively utilized in iodine internal dosimetry for Koreans.

The Priority of Internal Control Factors for Information Systems based on Individual Characteristics (개인 특성에 따른 정보시스템 내부통제요소 중요도에 관한 연구)

  • 박종은;이우형;이명호
    • Korean Management Science Review
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    • v.21 no.1
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    • pp.57-76
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    • 2004
  • The development of informational technology has lead to a sharp change in not only the existing way of operations and management, but the way of human life or thinking as well. Those shifts of the paradigm in information technology have also affected Individuals to the organizational structure. A series of unexpected problems was, however, accompanied by the advance in informational technology, which had broaden its own area of application. Those problems include the losses of property or data the malfunction of systems and their wastefulness would result in, continuous increases in computer crimes, reliability and efficiency of the functional process with the development of information systems, such as the processing problems of inaccurate data, economical issues, and subjects related to safety, as interruptions of privacy, which would result from lots of one's exposure to the drains of personal information. Accordingly, Auditors' roles of information systems, for now, is more important than anything else in that they are responsible for the objective assessment of relevance and effectiveness of internal control systems under the environment of information systems. The objective of the study is, so as to obtain safety of information systems: First, to provide data to line-design internal control systems after finding internal control factors to prevent and eliminate the risks of information systems. Second, to evaluate the priorities of internal control factors with their effective management being considered as the key to settle the problems of risks of information systems. Third, to discriminate what factors affect In evaluating the relative degrees of Importance of internal control factors.

A Case of Hypersensitivity Pneumonitis in an Automobile Paint Sprayer (자동차 페인트 도장공에서 발생한 과민성 폐렴 1예)

  • Oh, Mi Na;Cho, Myoung Jin;Baek, Hoon Ki;Cho, Ki Sung;Kang, Ji Hoon;Kim, Young;Kwak, Jin Young
    • Tuberculosis and Respiratory Diseases
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    • v.65 no.6
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    • pp.541-545
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    • 2008
  • Hypersensitivity pneumonitis (HP) is an immunologically-mediated disease resulting from repeated exposure to sensitizing agents, such as organic dusts or chemicals. Isocyanate is a volatile and highly reactive chemical that is extensively used in the manufacturing of automobiles, upholstery, and polyurethane foam. Occupational respiratory diseases associated with isocyanate, such as bronchial asthma, are well-known. It is thought that HP is one of the rare diseases induced by isocyanate with a very low frequency worldwide. We report a case of HP in an automobile painting sprayer which appeared to be associated with isocyanate.

A Case of Lipid Pneumonia by Green Perilla Oil (들깨 기름 흡인에 의한 지질폐렴 1예)

  • Kim, Hee-Jung;Jeong, Dae-Joon;Kim, Kyeong-Hyun;Kim, Se-Hyun;Lee, Seung-Joon;Kim, Woo-Jin;Han, Seon-Sook
    • Tuberculosis and Respiratory Diseases
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    • v.68 no.6
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    • pp.354-357
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    • 2010
  • Exogenous lipid pneumonia is a rare disease resulting from the aspiration or inhalation of vegetable, animal, or mineral oils. In Korea, the most frequently implicated agent is squalen, which can be obtained from shark liver oil. Lipid pneumonia by aspiration of the vegetable oil is very rare. We experienced a 77-year-old man with a history of ingestion of green perilla oil. His clinical course was favorable; after exposure to the oil was stopped, the patient's symptoms improved.