• 한국직업건강간호학회지
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• 제24권2호
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• pp.67-75
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• 2015

Purpose: The objective of the present study was to evaluate the effects of occupational exposure to low dose organic solvents on the prevalence of cardiovascular risk factors. Methods: Study design was retrospective cohort study subjected on 191 exposures and 118 controls working in a petrochemical manufacture company. The eight indicators related to CVD risk were followed up for five years from 2008 to 2012. The risk level was compared during the follow up years and subject's characteristics, and the change of risk level were analyzed with repeated measures ANOVA and multiple logistic regression analysis. Results: At the start year 2008, the rate over cutoff value (ROCV) of BS (p<.001) and mean systolic BP (p=.017) were higher in organic solvent exposure group and the others showed no difference. And by the subject's characteristics, odds ratio of the ROCV of BS were higher in organic solvent exposure group and work shift group as 2.51 and 3.07. Comparing the results in 2012 to those of 2008, cardiovascular disease risk in organic solvent exposure group was about 1.5 times higher than that of in the control group. Conclusion: Gradual increase in the CVD risk was identified in organic solvent exposure group. However, the risk might be influenced by shift work and bad behaviors rather than organic solvent exposure.

• 한국환경보건학회지
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• 제38권5호
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• pp.386-392
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• 2012

Objectives: This study aims to evaluate the blood concentrations and dietary intake for 24-hour food duplicate of low level polycyclic aromatic hydrocarbons (PAHs). Design: The geometric means of the blood concentrations and dietary intake of 16 PAHs in college student candidates were simply compared with instrumental detection. Methods: The concentrations of 16 PAHs in venous blood and 24-hour food duplicates were analyzed with head-space solid phase microextraction (HS-SPME) of gas chromatography-mass spectrometry. Results: Naphthalene, acenaphthylene, pyrene, benz(a)anthracene, chrysene, and acenaphthene among the 16 analyzed PAHs were simultaneously detected both in venous blood and 24-hour food duplicate samples. Conclusion: The main exposure source of the six PAHs is thought to be oral intake from food through low level non-occupational exposure.

• 방사선산업학회지
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• 제17권4호
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• pp.509-518
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• 2023

The Kori Unit 1 nuclear power plant, which is planned to be dismantled after permanent shutdown, is expected to generate a large amount of various types of radioactive waste during the dismantling process. For the disposal of Very-low-level waste, which is expected to account for the largest amount of generation, the Korea Radioactive waste Agency (KORAD) is in the process of detailed design to build a 3-phase landfill disposal facility in Gyeongju. In addition, a large container is being developed to efficiently dispose of metal and concrete waste, which are mainly generated as Very low-level waste of decommissioning. In this study, based on the design characteristics of the 3-phase landfill disposal facility and the large container under development, radiation exposure dose evaluation was performed considering the normal and accident scenarios of radiation workers during operation. The direct exposure dose evaluation of workers during normal operation was performed using the MCNP computer program, and the internal and external exposure dose evaluation due to damage to the decommissioning waste package during a drop accident was performed based on the evaluation method of ICRP. For the assumed scenario, the exposure dose of worker was calculated to determine whether the exposure dose standards in the domestic nuclear safety act were satisfied. As a result of the evaluation, it was confirmed that the result was quite low, and the result that satisfied the standard limit was confirmed, and the radiational disposal suitability for the 3-phase landfill disposal facility of the large container for dismantled radioactive waste, which is currently under development, was confirmed.

• Journal of Nutrition and Health
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• 제27권1호
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• pp.12-22
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• 1994

Effects of very low level of lead in diet and exposure time on the accumulation and distribution in organs and tissues was investigated with growing rats. 21 days old Sprague-Dawley rats were exposed to lead for 7, 14 and 21 days by feeding of 0.03, 0.42, 0.92 and 1.46mg/kg Pb as Pb-acetate containing diet, respectively. Lead concentrations in blood, liver, kidney and bone exhibit a linear relationship with lead levels in diet. After 7 days of exposure, the greatest dose dependent accumulation of lead was found in kidney and followed in bone. However, after 14 and 21 days, the dose dependent accumlation of lead in bone was about two fold greater than that in kidney. The accumulation of lead in liver and blood was relatively low. As continuous exposure to lead, the concentrations of lead in liver, kidney, blood and intestinal tracts were rather not increased with exposure time. However, bone lead concentration was increased with exposure time by feeding of 0.92 and 1.46mg/kg Pb in diet, but not 0.42mg/kg. The lead concentration in gastrointestinal tracts tends also to increasing with lead levels in diet after 7 and 14 days of exposure. However, by 21 days of exposure the lead concentration revealed relatively constant value regardless of the dietary lead levels. It is concluded that the binding capacity of the lead in blood, liver, kidney and bone seems to be increased with increasing lead levels in diet. The lead concentration in these organs, with the exception of the lead in bone, seems, however, to be standing under steady state regulation by continued exposure with the same dietary lead level. Therefore, by chronic exposure condition with environmental relevant lead level bone might be a principle targe organ for lead and blood lead repesents better the current lead exposure than the lead body burden.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.674-680
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• 2022

In the present study, radiation shielding and protection ability of prepared Flyash-lime-Gypsum (FaLG) bricks has been studied in terms of energy exposure build up factors and dose parameters. The energy exposure build up factors of Flyash-lime-Gypsum (FaLG) bricks have been calculated for the energy range of 0.015 MeV-15 MeV and for penetration depth upto 40 mfp directly using a new and simplified Piecewise Linear Spline Interpolation Method (PLSIM). In this new method, the calculations of G.P fitting parameters are not required. The verification and accuracy of this new method has been checked by comparing the results of exposure build up factor for NBS concrete calculated using present method with the results obtained by using G.P fitting method. Further, the relative dose distribution and reduced exposure dose rate for various radioactive isotopes without any shielding material and with Flyash-lime-Gypsum (FaLG) bricks have been calculated in the energy range of 59.59-1332 keV. On the basis of the obtained results, it has been reported that the prepared Flyash-lime-Gypsum (FaLG) bricks possess satisfactory radiation shielding properties and can be used as environmentally safe storage facilities for low level nuclear waste.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2003년도 학술대회
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• pp.7-11
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• 2003

Interactions of both feminizing and masculinizing chemicals inducing imposex in gastropod were investigated with a long-term exposure experiment. Imposex-free rock shell(Thais-clavigera)was exposed to TBT and other antagonistic chemicals (nonylphenol and DDT), P450 inducer (phenobarbital) and natural sex hormone (estrogen) mixtures for 60 days. None of imposexed-females were found in control, sham (ethanol) and testosterone exposure group, on the other hand imposex was induced in the TBT and all the TBT+antagonist mixture groups. After 60-day exposure, frequency of imposexed-female ranged from 31-68%. Female mean penis length (FMPL) of imposexed-female ranged from 0.87-2.58 mm, and relative penis length indices were from 7.2 to 21.2%. However, the degrees of imposex were different among the exposure groups. The FMPLS of three exposure groups (TBT+estrogen, + DDT and +nonylphe- not) were less than that of the TBT exposure group. Ethoxyresorufin-O-deethylase (EROD) activities in gastropod decreased in the TBT and all the TBT+antagonist ekposure groups compared to the control group. A negative correlation was abtained between TBT body residue and EROD activity, while a positive relationship was obtained between 737 body residue and the degree of imposex except for the TBT +DDT exposure group. Although 737 concentration was relatively high in the TBT+DDT exposure group, the TBT +DDT exposure group demonstrated low EROD activity and low degree of imposex. These results indicate that a certain antagonistic effect of DDT occurred in induction of imposex by TBT.

• 한국산업보건학회지
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• 제32권1호
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• pp.10-20
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• 2022

Objectives: The aim of this study is to evaluate exposure levels of the extremely low frequency magnetic fields(ELF-MF) radiated from various electric facilities in Liquid Crystal Display(LCD) manufacturing processes. Methods: This study measured the exposure levels of personal and local ELF-MF for the electronic facilities installed in two LCD manufacturing companies. Samplers were installed around workers' waist during working hours to identify personal exposure levels, and direct reading equipment were located at 3 cm, 10 cm, and 30 cm away from the surface of the electronic facilities to measure local exposure levels. Average and maximum(ceiling) values were calculated for personal and local exposure levels. Results: Average and maximum of personal exposure levels for each worker were 0.56(mean) ± 0.02(SE) µT and 6.31 ± 0.75 µT, respectively. Statistical analyses of the study found that maximum of the personal exposure levels for engineers was significantly higher than that for operators since engineers spend more time near the electronic facilities for repairing. The range of maximum personal exposure levels was 0.50 ~ 43.50 µT and its highest level was equivalent to 4.35 % of ACGIH(American Conference of Governmental Industrial Hygienists) exposure limit value(1 mT). Maximum of local exposure levels was 8.18 ± 0.52 µT and the electronic facilities with higher exposure levels were roof rail and electric panel, which were not related to direct manufacturing. The range of maximum local exposure levels was 0.60 ~ 287.20 µT and its highest level was equivalent to 28.7 % of the ACGIH exposure limit value. Lastly, the local exposure levels significantly decreased as the measurement distance from the electronic facilities increased. Conclusions: Maximum of personal and local exposure levels did not exceed the exposure limit value of ACGIH. However, it is recommended to keep the workers as far as possible from the sources of ELF-MF.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.144-144
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• 1998

The physiological responses caused by exposure of high- and low-level lead exhibit different phase. Low-level lead continuous hypertension, but high-level lead can in the development of hypertension. In this study it was tested which difference can be caused as lead levels and, if it can be caused, whether hematological changes are related with the hypertensive effects induced by different levels of lead exposure was tested. Lead intoxication in male SD rats was induced by exposure through drinking water containing 50, 200 and 1000 ppm lead (as lead acetate). The animals of control group was supplied drinking water containing sodium acetate ad libitum. The number of each animal group was 10. Systolic blood pressures were measured in the unanesthetized state by the tail-cuff technique at 0, 3, 7 and 16 weeks. RBC, WBC, MCV, hemoglobin, hematocrit and whole blood viscosity levels were examined.

• Environmental Analysis Health and Toxicology
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• 제18권4호
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• pp.237-242
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• 2003

Single cell gel electrophoresis (SCGE) was used to the experiment with the variation on the amount of smoking and low dose radiation exposure to find how much the Lymphocyte DNA was damaged, and especially for whom smoke a lot(about 20 or more than 20 cigarettes a day) it was found to be highly damaged. While, the damage of 'not more than 20 cigarettes a day' was found to be not so much significant as like for whom smoke about or more than 20 cigarettes a day And, according to the different amount of the radiation exposure, the Lymphocyte DNA was found to be considerably damaged for 0-13m Sv (P<0.01), it was not able to prove the relationship between the DNA damage and the radiation exposure.

• Journal of Preventive Medicine and Public Health
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• 제46권5호
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• pp.213-225
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• 2013

Objectives: The aim of this study was to evaluate the association between Agent Orange exposure and self-reported diseases in Korean Vietnam veterans. Methods: A postal survey of 114 562 Vietnam veterans was conducted. The perceived exposure to Agent Orange was assessed by a 6-item questionnaire. Two proximity-based Agent Orange exposure indices were constructed using division/brigade-level and battalion/ company-level unit information. Adjusted odds ratios (ORs) for age and other confounders were calculated using a logistic regression model. Results: The prevalence of all self-reported diseases showed monotonically increasing trends as the levels of perceived self-reported exposure increased. The ORs for colon cancer (OR, 1.13), leukemia (OR, 1.56), hypertension (OR, 1.03), peripheral vasculopathy (OR, 1.07), enterocolitis (OR, 1.07), peripheral neuropathy (OR, 1.07), multiple nerve palsy (OR, 1.14), multiple sclerosis (OR, 1.24), skin diseases (OR, 1.05), psychotic diseases (OR, 1.07) and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the division/brigade-level proximity-based exposure analysis, compared to the low exposure group. The ORs for cerebral infarction (OR, 1.08), chronic bronchitis (OR, 1.05), multiple nerve palsy (OR, 1.07), multiple sclerosis (OR, 1.16), skin diseases (OR, 1.05), and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the battalion/company-level analysis. Conclusions: Korean Vietnam veterans with high exposure to Agent Orange experienced a higher prevalence of several self-reported chronic diseases compared to those with low exposure by proximity-based exposure assessment. The strong positive associations between perceived self-reported exposure and all self-reported diseases should be evaluated with discretion because the likelihood of reporting diseases was directly related to the perceived intensity of Agent Orange exposure.