• Safety and Health at Work
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• v.8 no.2
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• pp.143-150
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• 2017

A huge number of chemicals are produced and used in the world, and some of them can have negative effects on the reproductive health of workers. To date, most chemicals and work environments have not been studied for their potential to have damaging effects on the workers' reproductive system. Because of the lack of information, many workers may not be aware that such problems can be related to occupational exposures. Newly industrialized countries such as Republic of Korea have rapidly amassed chemicals and other toxicants that pose health hazards, especially to the reproductive systems of workers. This literature review provides an overview of peer-reviewed literature regarding the teratogenic impact and need for safe handling of chemicals. Literature searches were performed using PubMed, Google Scholar, and ScienceDirect. Search strategies were narrowed based on author expertise and 100 articles were chosen for detailed analysis. A total of 47 articles met prespecified inclusion criteria. The majority of papers contained studies that were descriptive in nature with respect to the Medical Subject Headings (MeSH) terms and keywords: "reproductive and heath or hazard and/or workplace or workers or occupations." In the absence of complete information about the safe occupational handling of chemicals in Republic of Korea (other than a material safety data sheet), this review serves as a valuable reference for identifying and remedying potential gaps in relevant regulations. The review also proposes other public health actions including hazard surveillance and primary prevention activities such as reduction, substitution, ventilation, as well as protective equipment.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.265-271
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• 2013

Cryopreservation and in vitro fertilization (IVF) protocols are important in genetic studies and applications to transgenic animals. Various studies about boar sperm cryopreservation have been studied for a long time. Those were about the use of extenders, the choice of sugars, the cooling and warming rates. The factors that influence the boar sperm are the dramatic changes in temperatures, osmotic and toxic stresses, and reactive oxygen species (ROS) generation. Among these factors, ROS generation is the main damage to DNA which is a principal genetic material and the most important for the practical applications. So we wondered whether ROS generation could be reduced. In previous study, monothioglycerol (MTG) was essential for the culture of embryo stem cells. Therefore we added MTG in the freezing extender based on lactose-egg yolk (LEY) with trehalose. For the assessment of the frozen-thawed sperm, we focused onmotility, membrane integrity and DNA damage. First, we used a computer-aided sperm analysis system for overall conditions of sperm such as motility and viability. Then we performed the sperm chromatin structure assay for DNA integrity and hypo-osmotic swelling test for membrane integrity. And our result showed the existence of MTG in the freezing extender caused less damage to DNA and higher motility in frozen-thawed boar sperm. Also we checked a relative antioxidant activity of MTG in modified Modena B extender. We concluded that this reagent can activate sperm mitochondria at MTG $0.2{\mu}M$, contribute to sperm motility and DNA integrity but there was no significant difference on membrane integrity. Also antioxidant activity of MTG in modified Modena B extender was proved.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.181-191
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• 2007

With the 2-Butanethiol, which is an unidentified inhalation toxic material, acute inhalation toxicity was tested with SD rats. The $LC_{50}$ was evaluated to be 2,500 ppm (9.22 mg/L) or higher which falls under the criteria of acute toxicity Category 3 (500<$LC_{50}$<2,500 ppm) in the Industrial Safety and Health Act. In the subchronical inhalation toxicity test by 0, 25, 100, and 400 ppm, 6 hours a day, 5 days a week, for 13 weeks repeated exposure, though no death or particular clinical presentation was observed, in the female 25 and 400 ppm group, including weight change, and in each concentration group including 400 ppm, change of feed rate, eye stimulation, motility change in male group, and lesions in blood and blood biochemical were observed. In the internal organs weight, 25, 100, and 400 ppm groups in male and 400 ppm group in female showed significant (p<0.05) changes in kidney, liver, thymus, and lung. In the pathological tissue test, severe cortical tubular hyaline droplets were observed in the male 400 ppm group, and all male rats of 400 ppm group and 2 female individuals showed tubular degeneration/regeneration accompanied with pigmentation, showing that the target organs of inhalation exposure of 2-Butanethiol are spleen, kidney, nasal cavity, and adrenal. Through the tests, the NOEL of 2-Butanethiol was evaluated to be 25 ppm (0.092 mg/L) or less for both male and female.

• Toxicological Research
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• v.23 no.4
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• pp.373-382
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• 2007

This study was conducted to obtain acute information of the oral dose toxicity of PGB-1, a novel polyglucosamine polymer produced from a new strain Enterobacter sp. BL-2 in male and female mice. In order to calculated 50% lethal dose ($LD_{50}$) and approximate lethal dose (LD), test material was once orally administered to male and female ICR mice at dose levels of 2000, 1000, 500, 250, 125 and 0 (vehicle control) ml/kg (body wt.). The mortality and changes on body weight, clinical signs, gross observation and organ weight and histopathology of principle organs were monitored 14 days after dosing with PGB-1. We could not find any mortalities, clinical signs, body weight changes and gross findings. In addition, significant changes in the organ weight and histopathology of principal organs were not observed except for some sporadic findings. The results obtained in this study suggest that PGB-1 may not be toxic in mice and may be therefore safe for clinical use. The $LD_{50}$ and approximate LD in mice after single oral dose of PGB-1 were considered over 2000 mg/kg in both female and male mice.

• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.253-260
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• 2002

Fowl red mite, Dermanyssus gallinae, is the most important ectoparasite affecting egg layers worldwide. More than 35 compounds have been used for fowl red mite control. Although some of them are efficient, several compounds are unsuitable in terms of food safety and environmental problems. Some compounds are efficient in theory but inadequate in practice. It is also expensive in material and labor to control effectively. Effective doses are very close to toxic doses and repeated treatment is required. Repeated, long term treatment of compounds on fowl red mite populations, may cause heritable resistance against the mites. In this study, antigenicity of fowl red mite and house dust mite, Dermatophagoides pteronyssinus, were identified by SDS-PAGE, silver staining, Western blotting and ELISA to investigate immune effects against fowl red mite using somatic antigens of fowl red mite and house dust mite. By SDS-PAGE, silver staining and Western blotting, several common antigens (110, 60, 56, 49, 46 kDa) of both fowl red mite and house dust mite were recognized. To identify immune effect of somatic antigens of fowl red mite and house dust mite, sixty white leghorn broilers(1 week old) were used. Among sixty white leghorn broilers, twenty were immunized with fowl red mite somatic antigens(Group I), twenty immunized with house dust mite antigens(Group II), and twenty were control group without antigen(Group III), respectively. After immunization, it was identified that antibody titers were increased both in group and II. Then all groups were challenged with fowl red mites. After 2 months, measurements of body weights, packed cell volume(PCV), ELISA OD values and numbers of mites were significant(p<0.05). These results suggest that fowl red mite and house dust mite, which are easy to collect and maintain, can be good vaccine candidates against fowl red mite in chicken.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.3-5
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• 2008

An increase in oil and gas plants caused by development of process industry have brought into the increase in use of flammable and toxic materials in the complex process under high temperature and pressure. There is always possibility of fire and explosion of dangerous chemicals, which exist as raw materials, intermediates, and finished goods whether used or stored in the industrial plants. Since there is the need of efforts on disaster damage reduction or mitigation process, we have been conducting a research to relate explosion model on the background of real 3D terrain model. By predicting the extent of damage caused by recent disasters, we will be able to improve efficiency of recovery and, sure, to take preventive measure and emergency counterplan in response to unprepared disaster. For disaster damage prediction, it is general to conduct quantitative risk assessment, using engineering model for environmental description of the target area. There are different engineering models, according to type of disaster, to be used for industry disaster such as UVCE (Unconfined Vapour Cloud Explosion), BLEVE (Boiling Liquid Evaporation Vapour Explosion), Fireball and so on, among them, we estimate explosion damage through UVCE model which is used in the event of explosion of high frequency and severe damage. When flammable gas in a tank is released to the air, firing it brings about explosion, then we can assess the effect of explosion. As 3D terrain information data is utilized to predict and estimate the extent of damage for each human and material. 3D terrain data with synthetic environment (SEDRIS) gives us more accurate damage prediction for industrial disaster and this research will show appropriate prediction results.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.121-126
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• 2006

HVOF thermal spray coating of Co-alloy T800 is progressively replacing the classical hard coatings such as chrome plating because of the very toxic $Cr^{6+}$ ion known as carcinogen causing lung cancer. For the study of the possibility of replacing of chrome plating, the wear properties of HVOF Co-alloy T800 coatings are investigated using the reciprocating sliding tester both at room and at an elevated temperature of $1000^{\circ}F\;(538^{\circ}C)$. The possibility as durability improvement coating is studied for the application to the high speed spindles vulnerable to frictional heat and wear. Wear mechanisms at the reciprocating sliding wear test are studied for the application to the systems similar to the sliding test such as high speed spindles. Wear debris and frictional coefficients of T800 coatings both at room and at an elevated temperature of $1000^{\circ}F\;(538^{\circ}C)$ are drastically reduced compared to those of non-coated surface of parent substrate Inconel 718. This study shows that the coating is recommendable for the durability improvement coatings on the surfaces vulnerable to frictional heat. The sliding surfaces are weared by the mixed mechanisms such as oxidative wear, abrasion by the sliding ball slurry erosion by the mixture of solid particles and small drops of the melts and semi-melts of the attrited particles cavitation by the relative motions among the coating, sliding ball, the melts and semi-melts. and corrosive wear. The oxide particles and the melts and semi-melts play roles as solid and liquid lubricant reducing the wear and friction coefficient.

• KSBB Journal
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• v.17 no.2
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• pp.158-161
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• 2002

In this study, a prototype fiber-optic biosensor was fabricated using the inhibition of enzyme reaction by organophosphorus compounds to detect organophosphorus compounds, which is nervous toxic material an? is used as chemical weapon and pesticide. Enzyme, substrate, and inhibitor for enzyme reaction were acetylcholinesterase (key enzyme in nervous cell), acetylthiocholine iodide, and paraoxon (a kind of organophosphorus compounds), respectively. The detection principle of sensor is the detection of enzyme reaction inhibited by organophosphorus compounds by the quantitative measurement of acetic acid, which was achieved by absorbance measurement using litmus solution that maximum absorbance band is changed by pH. To fabricate prototype fiber-optic biosensor, high bright LED and photodiode was used as light source and light intensity detector, respectively. From the experimental results using a prototype biosensor, the linear change of sensor signal was obtained in a range of 0-2 ppm inhibitor concentrations. From these results, it was verified that the quantitative measurement of organophosphorus compounds could be achieved fast (within 2 minutes) and accurately by a prototype fiber-optic biosensor.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.52-58
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• 2017

One of the most important elements of the management of chemical accident is threat zone estimation of fires, explosions and toxic gas dispersion based on chemical releases. The threat zone estimation is going to be standard of emergency response for the first defender and base line data of off-site risk assesment (hereinafter referred to as "ORA") and risk management plan (hereinafter referred to as "RMP"). Generally, ALOHA form EPA(U.S.) and Kora(from KOREA MINISTRY OF ENVIRONMENT) has been used for the off-site consequence analysis in Korea. However it is hard to predict accurate consequences rapidly in case of emergency. Hydrochloric acid is a multipurpose raw material used in many industrial applications such as chemical, metal and food industries. It is usually treated in concentrations from 10 ~ 35 %, and release accident have occurred frequently. In this study, we have developed a simplified estimating method and equation to calculate threat zone easily in case of emergency due to release accident of hydrochloric acid.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5229-5232
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• 2012

The incidence of malignant melanoma increases with age. One significiant effect of aging processes is an accumulation of oxidative damage in the genetical material. In this study, the relationship between malignant melanoma and damage in chromosomes and proliferative effectiveness of human peripheral lymphocytes were investigated by the micronucleus (MN) technique. A total of 15 malignant melanoma patients and appropriately matching 15 healthy controls were involved in the study. MN frequencies and proliferative indexes (PI) after non toxic levels of hydrogen peroxide treatment were also measured to determine damaging effect of oxidative stress in genome in addition to measuring the spontenous levels of micronuclei and PI. The patient group had a significantly higher rate of spontaneous MN than the control group (p<0.01). After treatment with $H_2O_2$, MN frequencies in the patient group was significantly decreased (p<0.01) although there was no difference between the treated and untreated results of control group (p=0.29). There was also difference (p<0.01) between the MN frequencies of the patient and the control group either in the spontaneous levels or in the $H_2O_2$ treated groups. The same significant difference persisted when the PI values were compared between patient and control groups. Increase in the MN frequency in patients could mean the alterations in the chromosomal structure which may lead to the chromosome instability and therefore genetic susceptibility to cancer. This increased number of micronuclei can also be used for cytological marker in identifying high risk cases for malignant melanoma.