• Toxicological Research
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• v.8 no.2
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• pp.285-302
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• 1992

Human and rat hepatocytes were isolated by nonperfusion method and cultured for longer than 5 days. Human liver biopsy sample and rat liver were used as hepatocyte source. Several physical and chemical factors which were influencing on hepatocyte isolation procedure were examined and a batch isolation procedure was established for small size sample of rat liver. Isolated hepatocytes showed normal morphlologica characteristics in microscopy and electron microscopical examinations and a morphologica response to phalloidin. Isolated cells were cultured as a monolayer and proven to have intact morphological characteristics for longer than 15 days. Because human liver sample is harder and tighter compared with rat liver, a standard procedure for rat hepatocytes was slightly modified to reduce mechanical damage. Similarly with rat hepatocytes, isolated human hepatocytes showed a normal morphological characteristics and could be cultured for longer than 15days. Human and rat hepatocytes were examined on their functional integrities including cytochrome-P450 related enzyme activity and it's inducibility, hormonal inducibility of AIB uptake and TAT activity, albumin synthesis, DNA synthesis, cellular protein maintenance. In all parameters used in the present study, human and rat hepatocytes showed normal functional characteristics.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.217-223
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• 2012

Objectives: This study was conducted to evaluate personal and area exposure of airborne nicotine during harvest and weaving tasks in tobacco farms. Methods: Nicotine was measured with NIOSH method 2551 and Passive sampler which was validated in previous papers for area and personal sampling. Results: The average (geometric mean) concentrations of nicotine with two different tasks in personal sample were 6.5 ${\mu}g/m^3$ (harvest), 32.6 ${\mu}g/m^3$ (weaving) and in area sample were 0.8 ${\mu}g/m^3$ (harvest), 57.2 ${\mu}g/m^3$ (weaving). There was significant difference in area sample between harvest and weaving task (p=0.000). Also, there was significant difference with personal sample (p=0.000). Conclusions: It was found that weaving task should be considered to be the first priority for reducing nicotine exposure.

• Hwankyungkyoyuk
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• v.2 no.1
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• pp.5-33
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• 1991

The purpose of the study was to investigate attitudes toward to, values and expectations of environmental education of Korean students and teachers and to provide basic data and reference materials needed to development of environmental education curricula for primary and secondary schools. A review of the related literature, a series of conferences with teachers and specialists in environmental education and environmental sciences. and questionnaire survey were methods employed in this study. Survey question were developed to explore attitude and responses of primary and secondary school students and teachers on various types of issues and problems of environmental education at personal level as well as on their future prospects attitudes values and expectations with which had been dealt in this study were categorized into personal feeling on environmental issues and problems at both national and regional levels issues and problems of current environmental education pre service and in service training of teachers for environmental education instruction and so on. The sample population for the survey was selected by using the stratified cluster and random sampling techniques with respect to regional area, school level, sex and grade, The subjects used in this study were 1,633 students and 385 teachers of primary and secondary schools across the country. The results of the survey were summed up and recommendations to be considered in the revision of sixth national curricula for primary and secondary schools were also suggested.

• Economic and Environmental Geology
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• v.51 no.5
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• pp.429-438
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• 2018

Since concrete is a hardened aggregates of various materials, it needs to be crushed for chemical analyses. However, the effect of sample crushing on the analytical results has not been precisely assessed till today. In this study, we prepared concrete test pieces using Portand cements and fly ashes as binding materials, and ponded ashes and sands as aggregates and analyzed the heavy metals of the test pieces using Standards for Fair Testing of Soil Contamination (SFTSC) and Wastes (SFTW). For this, each test piece was partially crushed at first and sieved for separation of grains of <0.15 mm, 0.15-0.5 mm, and 0.5-5 mm from the same crushed samples (Crushing Method I). Results of those samples using SFTSC showed a clear trend that analyzed heavy metal concentrations are higher in the finer fractions. Particularly, fractions with <0.15 mm indicated much higher concentrations than the theoretical ones, which were calculated based on the concentrations of individual materials and their mixing fractions. In contrast, the analytical results were generally comparable with the theoretical ones when the test pieces were totally pulverized such that all the crushed grains were <0.15 mm in size (Crushing Method II). These results are associated with the fact that cement materials and fly ashes, which are high in heavy metals relative to other materials, are enriched in the fine fractions. The analytical results using the SFTW derived very low concentrations in most of parameters and did not indicate the dependence of concentrations on the crushing methods due to using distilled water as leaching agent.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.91-97
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• 2018

This study carried out first a component survey on the domestic waste shipped into a waste disposal facility in B city, and then heavy metal analysis of each component according to the SRF standards. Based on this, this study explored the problems with domestic waste and measures to improve them. The results are as follows. The result of the survey of physical components show that paper accounted for the largest proportion with 20.5 %~59.9 %, metals (including batteries) among incombustibles accounted for 0.0~8.3 %, other inorganic substances, glass and ceramics accounted for 0.0~43.7 % and 0.0 %~19.6 % respectively. However, the proportion of coated viny and plastics, which have high lead and cadmium content, was rather high with 2.9 %~30.9 %. This suggests the possibility that actual concentration of lead and cadmium within SRF is likely to be higher. Among the 15 components contained in the waste brought into the waste disposal facility, 10 components (food waste, textiles, vinyl, plastics, wood, rubber and leather, paper, metals, electronic substrates, and nail polish) were analyzed according to assay samples (approximately 0.1 g and 0.3 g). The result of analysis shows that the amount of Cd and Pb detected in coated vinyl for 0.109 g of assay sample was 98.6 mg/kg and 20.6 mg/kg respectively; 117.0 mg/kg and 29.0 mg/kg respectively for 0.313 g of assay sample. This is high contents exceeding the Cd standard. As for wooden component, the amount of Pb was 480.0 mg/kg for 0.3 g of assay sample. This suggests that there always exists the possibility of exceeding the exposure level of heavy metals (Cd and Pb) in SRF as long as coated wood and vinyl plastics with high contents of Pb and Cd are shipped into the waste disposal facility; and the local government and the residents need to work hard to improve the situation including development of the machine to sort electronic substrates and batteries for separate collection of the waste of coated vinyl and plastics within domestic waste.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.273-284
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• 2019

Objective: This study was performed to estimate the number of those who used humidifier disinfectants (HDs) and experienced health effects from exposure to HDs in Korea between 1994 and 2011. Methods: A nationwide interview survey was conducted for the representative sample to identify the proportion of those who used HDs among the general population (n=3,001). Another online survey was conducted for those exposed to HDs to find the proportion of those who experienced health effects among those who were exposed to HDs (n=3,993). Statistics for population size by region and year (1994-2011) were used to estimate the cumulative number of those exposed to HDs and those who experienced health effects. In terms of the proportion of those exposed to HDs, those less than 30 years of age were excluded due to an issue related to information bias. Various approaches for estimation included the capture-recapture method for estimation of those who experienced health effects. Results: The cumulative proportion of those exposed to HDs was 6.7% among the general population, and the proportion of those who experienced health effects among those who were exposed to HDs was 13.9%. Based on these factors, it was estimated that 3.5 to 4.0 million people were exposed to HDs and 350 to 400 thousand experienced health effects at least requiring visiting a hospital. Conclusion: It is suggested that a nationwide representative sample may be essential for population size estimation of those exposed to environmental risk factors and of those who experienced health effects.

• Asian Journal of Atmospheric Environment
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• v.11 no.2
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• pp.107-113
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• 2017

This study describes (1) the impact of positive sampling artifacts caused by not only a filter-based sampling, but also a denuder-based sampling in the determination of particle-phase organic carbon (POC), (2) the effect of sample flow rate on positive artifacts, and (3) an optimum flow rate that provides a minimized negative sampling artifact for the denuder-based sampling method. To achieve the goals of this study, four different sampling media combinations were employed: (1) Quartz filter-alone (Q-alone), (2) quartz filter behind quartz-fiber filter (QBQ), (3) quartz filter and quartz filter behind Teflon filter (Q-QBT), and (4) quartz filter behind carbon-based denuder (Denuder-Q). The measurement of ambient POC was carried out in an urban area. In addition, to determine gas-phase OC (GOC) removal efficiency of the denuder, a Teflon filter and a quartz filter were deployed upstream and downstream of the denuder, respectively with varying sample flow rates: 5, 10, 20, and 30 LPM. It was found that Q-alone sampling configuration showed a higher POC than QBQ, Q-QBT, and Denuder-Q by 12%, 28%, and 23%, respectively at a sample flow rate of 20 LPM due to no correction for positive artifact caused by adsorption of GOC onto the filter. A lower quantity of GOC was collected from the backup quartz filter on QBQ than that from Q-QBT. This was because GOC was not in equilibrium with that adsorbed on the front quartz filter of QBQ during the sampling period. It is observed that the loss of particle number and mass across the denuder increases with decreasing sample flow rate. The contribution o f positive arti facts to POC decreased with increasing sample flow rate, showing 29%, 25%, and 22% for 10, 20, and 30 LPM, respectively. The 20 LPM turns out to be the optimum sample flow rate for both filter and denuder-based POC sampling.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.15-21
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• 2024

The Non-Proliferation Treaty (NPT) is the basis of global efforts to prevent the spread of nuclear weapons. In Republic of Korea, safety measures are integrated with NPT approval through agreements with the International Atomic Energy Agency (IAEA) and the Safeguards Agreement. In contrast, Democratic People's Republic of Korea (DPRK), initially an NPT member, withdrew, refusing IAEA nuclear inspections. This inhibits the precise management of DPRK's nuclear facilities and limits access to related information. The Korean Peninsula, politically divided, sees DPRK in control of nuclear weapons. Although the IAEA periodically evaluates DPRK's nuclear facilities, there's a research gap in contamination and site management with nuclear activities. Recognizing the presence or absence of such activities is crucial for peaceful nuclear endeavors. This proposal suggests the number and locations for environmental sample collection using the Visual Sample Plan (VSP) software for nuclear activity analysis. VSP software is sample collection locations and quantities through statistical tests on collected data, ensuring reliability for decision-making. The proposal identifies sites and facilities for nuclear activity analysis based on IAEA safety reports, utilizing the software's embedded methods. Suggested sampling locations for undisclosed nuclear activities employ VSP's embedded techniques, including 'Show that at least some high % of the sampling area is acceptable' to confirm contamination and 'Estimate the Mean' to evaluate the average contamination level.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.352-357
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• 2006

This experimental study was designed to investigate the effects of Acanthopanax sessiliflorus $S_{EEM}$ leaves, stems, roots (ACL, ACS, ACR) on the change of weight and the serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, free fatty acid, total lipid and phospholipid level in obese mice induced Dy high fat diet. Experimental groups were as follows ; Normal group was fed with normal diet and administered with distilled water during 7 weeks, Control group was fed with high fat diet and administered with distilled water during 7 weeks, Sample A group was fed with high fat diet and administered with ACL of 500 mg/kg/mouse/day during 7 weeks, Sample B group was fed with high fat diet and administered with ACS of 500 mg/kg/mouse/day during 7 weeks, Sample C group was fed with high fat diet and administered with ACR of 500 mg/kg/mouse/day during 7 weeks. The results were as follows ; 1. Sample A group, Sample B group and Sample C group were significantly decreased the serum total lipid level in comparison with Control group. 2. Sample A group was decreased the body weight (4 weeks, 7 weeks), the serum total cholesterol level, the serum LDL-cholesterol level, the serum triglyceride level, the serum free fatty acid and phospholipid level but increased the serum HDL-cholesterol level in comparison with Control group. 3. Sample B group was increased the serum HDL-cholesterol level but decreased the body weight (4weeks), the serum total cholesterol level, the serum free fatty acid and triglyceride level in comparison with Control group. 4. Sample B group was significantly decreased the body weight (7 weeks), the serum LDL-cholesterol and phospholipid level in comparison with Control group. 5. Sample C group was increased the serum HDL-cholesterol level but decreased the body weight (4 weeks) and the serum free fatty acid level in comparison with Control group. 6. Sample C group was significantly decreased the body weight (7 weeks), the serum total cholesterol level, the serum LDL-cholesterol and triglyceride level in comparison with Control group. According to above results, I suggest ACR is able to be used for the obesity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1477-1484
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• 2006

This experimental study was designed to investigate the effects of Acanthopanax sessiliflorus $S_{EEM}$ extracts following gamma-ray irradiation on the change of weight, the serum total cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, free fatty acid, total lipid, phospholipid level in obese mice induced by high fat diet, and the change of regional cerebral blood flow (rCBF) and blood pressure (BP) in normal rats. Experimental materials were as follows ; 10AS was the bark powder of Acanthopanax sessiliflorus $S_{EEM}$ stems which was exposed in 10 kGy electron beam, 10AS was the bark powder of Acanthopanax sessiliflorus $S_{EEM}$ roots which was exposed in 10 kGy electron beam, 100S was the bark powder of Acanthopanax sessiliflorus $S_{EEM}$ stems which was exposed in 100 kGy electron beam, Experimental groups were as follows ; Normal group was fed with normal diet and administered with distilled water during 5 weeks, Control group was fed with high fat diet and administered with distilled water during 5 weeks, Sample A group was fed with high fat diet and administered with 10AS of 300 mg/kg/mouse/day during 5 weeks, Sample B group was fed with high fat diet and administered with 10AR of 300 mg/kg/mouse/day during 5 weeks, Sample C group was fed with high fat diet and administered with 100AS of 300 mg/kg/mouse/day during 5 weeks. The results were as follows ; Sample A group, Sample B group and Sample C group were significantly decreased body weight and the serum LDL-cholesterol, triglyceride, total lipid level in comparison with Control group. Sample A group, Sample B group and Sample C group were significantly increased the serum HDL-cholesterol level in comparison with Control group. Sample B group and Sample C group were significantly decreased the serum total cholesterol, free fatty acid and phospholipid level in comparison with Control group. This results were suggested that all experimental materials were able to be used for the obesity. 10AS did not changed rCBF and MABP in a dose-dependent manner. 10AR significantly increased rCBR in a dose-dependent manner, and BP did not change in a dose-dependent manner. 100AS decreased rCBF and BP in a dose-dependent manner. This results were suggested that 10 AR significantly increased rCBF by dilating pial arterial diameter. According to above results, the authors suggested that 10AR was able to be used for the obesity and ischemic disease.