• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.560-568
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• 2007

The aim of this study is to investigate the terminology of chemically unclear ‘heavy metals' which were expressed in the Korean secondary science textbook in terms of the definition, the type and the meaning. Initial results showed that six of ‘Chemistry I' textbooks among these texts defined a heavy metal with the density and described it as a metal which is hazardous and continuously accumulated in the human body. Specifically, cadmium, lead and mercury were presented as examples of the hazardous metal in all of the eight textbooks but non-metals such as arsenic and absolutely essential metals including chrome, manganese, iron, cobalt, nickel and copper were also given in the texts. Most of the texts described the hazardousness and toxicity of the metal too simple to understand the mechanism of its intoxication despite considering all of the factors including its oxidation state, residual amount and reactivity with biomolecules of the human body. Such an ambiguous definition and explanation may excluded in the textbook because the chemically undefined chemical vocabulary leads students to cause an alternative conception of the heavy metal, which means that the metal could be identical with toxins.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.179-189
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• 2001

This study was performed to identify the current status of work environment management and to provide appropriate recommendations for small scale industry with less than 5 workers from September, 2000 to October, 2000 in Seoul city and Gyoung-gi province. The 211 companies were surveyed by checklist included the elements of management of work environment, hazardous chemicals, MSDS, personal protective equipment, and ventilation system. The proportion of metal products manufacturing and printing industries are 25.6 % and 22.3%, respectively. The daily working hours in printing industry is longer than others. The industries that produce potentially hazardous agents, such as noise, dust, metal, organic solvents, radiation and chemical material are pulp, plating, machinery, and printing, respectively. In above industries, only 2.8 % of those recognised and had MSDS. The proportion of companies providing fire extinguishers, safety showers are found to be 13.3 %, 7.1 %, respectively. Only 24.2 % of companies provided personal protective equipment to the workers. The ventilation system was operated in most of companies. But local exhaust ventilation system is provided to 22.3 % of those, also had not been annually inspected. This study showed that the current status of occupational safety and health was not appropriate for workers in small scale industries. It is suggested that annual physical examination have to be performed, MSDS usage must become widespread, and employer and emplyees in small scale industry should be educated for the treatment and storage of hazardous chemicals to improve the occupational safety and health of the working environment. also, regulatory standard has to be applied to local exhaust ventilation system in small scale industry to improve the working condition.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.201-208
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• 2005

This study was conducted to investigate the effect of blanching time on changes of hazardous factors in leafy vegetables treated by systemic and non-systemic pesticides. Changes of hazardous factors in leafy vegetables treated by systemic and non-systemic pesticides showed the same trend. In changes of microbial counts in leafy vegetables according to blanching time, the total plate count was significantly decreased by blanching and total coliforms were not detected in any of the vegetables. In traceable metal contents of fresh vegetables before washing, the levels in spinach, chard and whorled mallow were 0.042, 0.040 and 0.032 ppm for Pb, 0.020, 0.023 and 0.019 ppm for Cd, and 0.029, 0.034 and 0.030 ppm for As, respectively. Therefore, the levels of Pb, Cd and As in leafy vegetables were very traceable and in terms of food safety there was no problem. On the other hand, the traceable metal contents in leafy vegetables did not show significant difference by blanching and blanching time. Nitrate contents in fresh vegetables before washing were detected at traceable levels. The nitrate contents in spinach, chard and whorled mallow were significantly decreased by $22\%,\;17\%\;and\;14\%$ after blanching time of 5 min, 9 min and 10 min, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.235-247
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• 1999

This study was performed to investigate what was the most serious occupational factors in small scale industries. Twenty-three occupatonally hazardous substances were measured at the five workplaces in the Eastern Seoul during 1995∼1996. Total of 2,020 samples were analyzed by either GC/FID for organic vapors or AAS for heavy metals. From the results of this study noise was the most serious factor at the selected workplaces. Noise level in the metal processing, the printing, and the auto repairing industries exceeded the 8 hr PEL by 19.7%, 13.6%, and 11.6%, respectively. Mean concentrations of toluene in the shoe making and the printing industries exceeded the assessment crieterion by 6.0% and 3.8%, respectively. Further study of risk assessment of occupational exposure may be required to protect workers from hazardous working conditons.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.56-57
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• 2018

This study is a fundamental consideration for using CGS from the IGCC as a fine aggregate for concrete. For the review, the physical properties and hazardous materials content of KS F 2527 were considered. The results showed that KS F 2527 standard was generally satisfied, making it possible to confirm the possibility that it is a fine metal considering its physical properties and hazardous materials content characteristics.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.370.1-370.1
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• 2016

Volatile organic compounds (VOCs) are considered hazardous air pollutants and these are emitted from building materials and household products. VOCs can cause global warming as well as human sickness, and even cancer. Photocatalysis provides a way of converting VOCs into harmless materials. Various researches have shown that $TiO_2$ is the most efficient photocatalysts due to its excellent activity. In this study, metal/non-metal doped $TiO_2$ particles are synthesized for the enhancement of the photocatalytic properties of pure $TiO_2$. By metal/non-metal doping, band gap energies of prepared samples were analyzed by UV/Visible spectrophotometer. The physical and chemical properties of synthesized powder were characterized by field emission scanning electron microscope, by BET for measuring their specific surface area, and by XRD for phase identification and particle size determination. Degradation ability for p-xylene was evaluated through monitoring the concentration in a closed chamber. Relation between their properties and decomposition abilities for VOC were evaluated based on the experimental results.

• Journal of Pharmacopuncture
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• v.23 no.2
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• pp.71-78
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• 2020

Objectives: This study was conducted to development of hazardous materials management standards for the decoction type of personalized herbal medicines (PHMs). Methods: This study was conducted in two stages. We searched documents about criteria to use words such as 'Herb', 'Herbal medicine', and 'Botanical Drug' and summarized the results. We organized the committee consisted of seven experts, and held two meetings to reach an agreement on hazardous management standards of the decoction type of PHMs. Results: The seven documents were presented in the literature review and six items related to hazardous management standards of decoction were identified. The second expert meeting brought that a total of six items, including heavy metal, pesticide residues, sulfur dioxide, benzopyrene, mycotoxin, and micro-organism limits, were selected for safety management of decoction type of PHMs. Also, the criteria and test methods for each standard were suggested for monitoring the decoction type of PHMs. Conclusion: The study suggested hazardous material management standards and criteria for the decoction types of PHMs. In the future, it would be necessary to conduct a pilot test to ensure the validity and credibility of the safety management standard and criteria. Furthermore, the government level safety management system should be introduced to verify the safety of decoction medicines.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.120-125
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• 2014

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.117-129
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• 2002

Concentration of welding fumes and their components is known to be hazardous to welder and adjacent worker. To determine the generation rates of metals in fumes, $CO_2$ flux cored arc welding on stainless steel was performed in well designed fume collection chamber. Variables were different products of flux cored wire(2 domestic products and 4 foreign products) and input energy(low-, optimal- , high input energy). Mass of welding fumes was determined by gravimetric method(NIOSH 0500 method), and 17 metals were analysed by inductively coupled plasm-atomic emission spectroscopy(NIOSH 7300 method). Flux cored wire tube and flux were analysed by scanning electron microscopy to determine their metal composition. 17 metals were classified by their generation rates. Generation rates of iron, manganese, potassium and sodium were all above 50mg/min at optimal input energy level. Generation rates of chromium and amorphous silica were 25~50mg/min. At 1~25mg/min level, nickel, titanium, molybdenum, and aluminum were included. Copper, zinc, calcium, lead, magnesium, lithium, and cobalt were generated below 1 mg/min. Generation rates of metal components in fumes were influenced by input energy, types of flux cored wire. Flux cored wire was consisted of outer shell tube and inner flux. Iron, chromium, and nickel were the major components of outer tube. Flux contained iron, chromium, nickel, potassium, sodium, silica, and manganese. The use of flux cored wire can increase the hazards by increasing the amounts of fumes formed relative to that of solid wire. The reason might be the direct transfer of elements from the flux, since the flux is fine power. Ratio of metals to the fume of flux cored wire was lower than that of solid wire because non-metal components of flux were transferred. Total metal content of fumes in flux cored arc welding was 47.4(24.3~57.2) percent that is much lower than that of solid wire, 75.9 percent. We found that generation rates of iron, manganese, chromium and nickel, all well known to cause work related disease to welder, increased more rapidly with increasing input energy than those of fumes. To reduce worker exposure to fumes and hazardous component at source, further research is needed to develop new welding filler materials that decrease both the amount of fumes and hazardous components.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.66-77
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• 2023

Background: Along with the increase in consumer interest in and consumption of tattoo products, the controversy over harmful heavy metals associated with the use of tattoo cosmetics is also increasing. Therefore, investigation of hazardous metals in these tattoo products is needed. Objectives: This study was performed to provide useful data for establishing reasonable standards to securely manage tattoo cosmetics, tattoo stickers, and tattoo inks distributed in the market. Methods: Thirteen kinds of hazardous metal contents (Pb, As, Cd, Sb, Ni, Co, Cu, Cr, Se, Ba, Zn, Sn, and Hg) were analyzed for 23 tattoo cosmetics, ten tattoo stickers, and 16 tattoo inks. Hg was measured through the combustion-gold amalgamation method, and other hazardous metals were measured by inductively coupled plasma-mass spectrometry (ICP-MS) after acidic decomposition using a microwave apparatus. Results: The detected ranges of Pb, As, Cd, Sb, Ni, and Hg in tattoo cosmetics were 0.07~1.18, 0.06~0.41, ND~0.07, 0.01~3.44, 0.12~2.75, and ND~0.01 ㎍/g, respectively. All of the hazardous metals detected were below the recommended maximum standards of the Ministry of Food and Drug Safety. The mean amount of Pb detected in tattoo stickers for children was 0.24 ㎍/kg and Cd was not detected, meaning both metals met the recommended criteria. There was no statistically significant difference in all measured metals between children's tattoo stickers and adults' tattoo stickers. In the results of the study on the hazardous metal content of tattoo inks, four products (25%) for Pb, one product (6%) for As, 13 products (81%) for Ni, four products (25%) for Cu, and five products (31%) for Zn exceeded the recommended standards approved by the government. The highest predicted exposure amount for hazardous metals exceeding the recommended level of tattoo inks in a single tattooing was 5.69 ㎍/kg for Ni, 8.51 ㎍/kg for Zn, 0.44 ㎍/kg for Pb, 8.07 ㎍/kg for Cu, 0.44 ㎍/kg for As, and 71.36 ㎍/kg for Ba. Conclusions: It is necessary to prepare criteria for content limitation for the management of Co, Cr, Ba and Se tattoo cosmetics, and tattoo inks require thorough quality control.