• Culinary science and hospitality research
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• v.22 no.8
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• pp.149-156
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• 2016

The purpose of this study is to reduce the contaminants (total volatile organic compounds (TVOCs), fine particle, odor and total airborne bacteria) during cooking process in cooking chamber, and to decrease the health damage in indoor space that has bad work environment. In order to solve the shortcomings of existing air purifiers and remove all kinds of pollutants effectively, this study focused on the development of indoor air purifiers which are made of bar type. Bio-ceramics filter which combines activated carbon and loess. The air cleaners developed with 4 measuring items including TVOCs, particulate matter, complex odor and total airborne bacteria were measured comparing their pre-service test to their post-service test after a period of time. The measured results showed higher removal efficiency of 91.02% as the concentration of TVOCs was reduced from $2,500{\mu}g/m^3$ to $223{\mu}g/m^3$. Second, the particulate matter removal ratio was 97.51% efficient with average concentration of $26.68{\mu}g/m^3$. Third, the odor showed 95.20% reduction as air dilution ratio averaged out at 144. Last, total airborne bacteria was eliminated by over 94% showing the changeable concentration from $787{\sim}814CFU/m^3$ to $47{\sim}40CFU/m^3$. In addition, the removal rate of harmful pollutants is excellent, and it is expected that the environment of the existing poor cooking room will be greatly improved by using the developed air purifier in combination with the ventilation device and the stove hood.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.3
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• pp.265-274
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• 2016

Purpose: The aim of this study was to evaluate relationship between worker's ophthalmoxerosis symptom and IAQ (Indoor Air Quality) variation after planting indoor plants at newly-built office building. Methods: We selected a new office building located in Sejong-si and occupants who work in the Office for study. The indoor air pollutant was investigated according to applying indoor plants. The indoor air quality of the new building was evaluated by measuring volatile organic compounds (VOCs), aldehydes, temperature and humidity. The level of dry eye symptoms was classified into normal, mild, moderate and severe by using the Ocular Surface Disease Index (OSDI). Results: There was VOCs' reduction effect according to placing indoor plants because the concentration of VOCs in newly-built government office (Sejong-si) was highly decreased when the indoor plants was placed at the office. The occupants' SBS (Sick Building Syndrome) symptoms score was gradually decreased in accordance with applying indoor plants. However, SBS symptoms score was increased when the office was not applied indoor plants. There was not statistical significance in workers' dry eye questionnaire results. Conclusions: There was reduction effect of indoor air pollutant in applied indoor plants office. Also, in case of questionnaire results of ophthalmoxerosis and SBS (Sick Building Syndrome) symptoms score were showed positive effect. This study is needed longer-term study because of complements of difference of individual sensitivity and there are some limitations due to field survey research.

• Applied Chemistry for Engineering
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• v.28 no.3
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• pp.332-338
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• 2017

The objective of this work was to study the low temperature vacuum adsorption technology applicable to small and medium scale painting plants, which is the main emission source of volatile organic compounds. The low-temperature vacuum swing adsorption (VSA) technology is the way that the adsorbates are removed by reducing pressure at low temperature ($60{\sim}90^{\circ}C$) to compensate disadvantages of the existing thermal swing adsorption (TSA) technology. Commercial activated carbon was used and the absorption and desorption characteristics of toluene, a representative VOCs, were tested on a lab scale. Also based on the lab scale experimental results, a $30m^3min^{-1}$ VSA system was designed and applied to the actual painting factory to assess the applicability of the VSA system in the field. As a result of lab scale experiments, a 2 mm pellet type activated carbon showed higher toluene adsorption capacity than that of using 4 mm pellet type, and was used in a practical scale VSA system. Optimum conditions for desorption experiments were $80{\sim}90^{\circ}C$ and 100 torr. In the practical scale system, the adsorption/desorption cycles were repeated 95 times. As a result, VOCs discharged from the painting factory can be effectively removed upto 98% or more even after repeated adsorption/desorption cycles when using VSA technology indicating potential field applicabilities.

• Clean Technology
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• v.23 no.4
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• pp.364-377
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• 2017

In this study, to improve the low surface area of domestic anthracite as raw materials of activated carbon, characteristics on chemical activation and VOCs adsorption of activated carbon according to mixing ratio of anthracite and lignite. For these, properties of raw materials, parameter characteristics of preparation processes for activated carbon, and VOCs adsorption characteristic of the prepared activated carbon are analyzed. The experimental results showed that, the domestic anthracite had disadvantages of high contents for ash and lead, arsenic, which were exceeded for the heavy metal limits, in the properties of raw materials. To improve these diadvantages, using the mixing ratio of anthracite and lignite, and the optimum conditions for pretreatment, activation, washing, and pellitization process, the activated carbon had a range of BET (Brunauer-Emmett-Teller) surface area of $1,154{\sim}1,420m^2g^{-1}$ with mesopore development and hydrophobic surface property. The carbons were satisfied with the quality standard for granular activated carbon, and had similar physicochemical properties with the commercial activated carbon. The minimum mixing condition for commercial VOCs activated carbon performance must have the caloric value of above $5,640kcal\;kg^{-1}$, and the carbon had higher adsorption capacity with order of xylene > toluene > benzene according to more higher molcular weight and hydrophobic property.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.314-319
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• 2013

In this study, nitrogen doped $TiO_2$ ($N-TiO_2$) coated on an activated carbon pellet (ACP) was prepared using sol-gel and the solid state heat treatment of urea to improve the removal property of volatile organic compounds (VOCs). To explore the visible light photocatalytic activity of the ACP under the light emitting diods (LED), the removal property of benzene gas was characterized by gas chromatography. The SEM and BET results show that the increment of titanium tetra isopropoxide contents leads to the increased $TiO_2$ coating amount of ACP surface and decreased specific surface area. From the results of benzene gas removal, the breakthrough time of ACP10 increased about 2 times compared to that of the ACP. The improved performance was attributed to the $N-TiO_2$ coating on ACP surface, which could be more effective to remove benzene gas under the condition of LED lamp.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.137-141
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• 2007

This experiment was conducted to investigate the effects of dietary yeast (Saccharomyces exguus) supplementation on growth performance, cecal microflora and fecal ammonia gas in broiler chicks. A total of two hundred seventy, 1-d-old male broiler chicks (Ross strain) were randomly allotted to nine pens (replicates), 30 birds per pen. There were three dietary treatments with three replicates. The treatments were control (virginiamycin 0.05%+salinomycin 0.03%), Saccharomyces exguus 0.5 and 1.0%. Total body weight gain were significantly higher in Saccharomyces exguus1 1.0% treatment than the control (P<0.05). Although not significant, the yeast supplementation tended to improve the feed conversion ratio. No significant differences were observed on the numbers of cecal E. coli, Salmonella and Lactobacillus in yeast treatments compared to those of control. The production of fecal ammonia gas was significantly lower in yeast treatments than the control (P<0.05). The concentrations of fecal short chain fatty acids and volatile organic compounds were not different among the groups. These results suggest the possibility that yeast (Saccharomyces exguus) could be used as the alternative of antibiotic growth promoters by improving the performance of broiler chicks. In addition, dietary yeast could improve the environment of broiler houses by reducing fecal ammonia production.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.381-389
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• 2009

Confined spaces are inherently dangerous workplace and many fatal and nonfatal accidents have been reported. Even though these accidents occur in various kinds of confined spaces, there has rarely been reported on the health hazard agent, i.e., the types of gases and their concentration ranges. Therefore in this study, we evaluated several toxic and asphyxiating gas concentrations in various confined spaces. We surveyed 57 manholes, 3 sewage treatment plants, 2 yellow radish manufacturing companies and 7 barges to measure the concentrations of oxygen($O_2$), hydrogen sulfide($H_2S$), carbon monoxide(CO), ammonia($NH_3$). Lower Explosion Limits(LEL) and Volatile Organic Compounds (VOCs). Those four types of confined spaces occupies 56% of accidents during last 9 years in Korea. In 57 manholes, the concentration varied according to the types of manholes; rainfall and sewage, and by location; residential and industrial areas. Sewage manhole in industrial area was evaluated as the most hazardous than other types of manhole like rainfall manholes, residential sewage manholes. The highest $H_2S$ concentration and the lowest $O_2$ concentration at sewage manhole in industrial area were 300 ppm, 8.7% respectively. In 3 sewage treatment plants, $H_2S$ and $NH_3$ concentrations were reached up to the 500 ppm and 200 ppm respectively. Two yellow radish manufacturing companies showed the concentrations of 316 ppm, 505.2 ppm, 90 ppm and 15.7% for $H_2S$, CO, VOCs and $O_2$, respectively. Seven barges showed 15.9%~20.9% oxygen concentration. Gas species and concentration ranges varied by the types and location of confined spaces; CO, $H_2S$, $O_2$ could be hazardous in manhole, especially manhole connected to sewage plants. CO, $H_2S$, LEL, $O_2$, $NH_3$ should be controlled in sludge silo and sluge pumping confined spaces in sewage treatment plant. The activity of lifting out radish from the storage tank was evaluated more hazardous rather than the other activities in yellow radish manufacturing industry. The employers must conduct the survey to identify all possible confined spaces in their local workplace prior to performing the tasks. At the national level to reduce the accidents in the confined spaces, we suggest that systemic approach and active education program including possible hazards, standard operation procedures, ventilation plan, and personal protective equipment in confined spaces should be implemented.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.2
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• pp.87-96
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• 2017

In this study, 4 gases containing typical chlorinated volatile organic compounds (VOCs) were treated by ultraviolet (UV) irradiation. The typical chlorinated VOCs are dichloromethane (DCM), trichloromethane (TCM), carbon tetrachloride (CTC) and trichloroethylene (TCE). The removal efficiency (RE) and the products of chlorinated VOCs by UV irradiation are investigated. At this time, 2 types of background gas (air and nitrogen) were used to figure out the RE by photooxidation and photolysis. The specification of UV-lamp used in this study was low-pressure mercury lamp emitting wavelength of 185~254 nm. The experimental conditions were set as initial VOC concentration of $180{\pm}10ppm$, empty bed retention time (EBRT) of 53 s, temperature of $23{\pm}2^{\circ}C$ and relative humidity of $65{\pm}5%$. In the photolysis condition with nitrogen ($N_2$) as background gas, the averaged RE of the 4 types of chlorinated VOCs was about 24% higher than that with photooxidation; and the REs of VOCs except CTC were confirmed as >99%. The composition of off-gases after UV photooxidation in air was investigated and several intermediates from DCM, TCM and TCE were detected by GC/MS. Among them, phosgene which is a toxics was detected as an intermediate of TCM. In addition, the concentration of carbon dioxide ($CO_2$) in the off-gases was measured to calculate the mineralization rate (MR). With the photooxidation, TCE showed the highest RE (>99%) while MR was the lowest (17%); and the MR of DCM was the highest (86%). In addition, particulate matters (PM) in the off-gases was also detected and high concentrated $PM_{10}$ ($21,580{\mu}g{\cdot}m^{-3}$) and $PM_{2.5}$ ($6,346{\mu}g{\cdot}m^{-3}$) were detected in TCE off-gas. More than 99% of the chlorinated VOCs could be removed using UV254-185 nm lamp, while it is necessary to conduct further studies on the production and treatment of secondary pollutants.

• Korean Journal of Community Nutrition
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• v.16 no.4
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• pp.466-472
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• 2011

Hazardous chemicals, such as polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and heavy metals, are known as being harmful to human health were included in oils released by the Herbei Spirit Oil Spill accident in December 2007. To investigate changes of eating habits by the exposure to harmful substances, we conducted 5 focus group interviews for residents at Taean coast areas, who had experienced the oil spill accident. Participants included 46 women (mean age: $57.2{\pm}10.9$) who were mainly responsible for preparing family meals. Focus group discussions were audio-taped, transcribed and categorized by themes. Participants expressed more frequent illness symptoms such as dizziness, vomiting, visual loss, and skin diseases after the accident. They mentioned that their worries about economic hardship and worsened health status since the accident induced mental problems, such as depression about their children. Regarding eating habits, participants reported less intakes of fishes and meats and relatively more intakes of vegetables and kimchi due to the lack of household incomes after the accident. Although the participants had been used to collecting or catching fish or shellfish for their consumption previously, they mainly purchased these foods from local markets after the accident. Changes of eating habits induced by the accident included drinking boiled water and having steamed or fried seafood rather than raw seafood. Changes of food intakes occurred less frequently in older adults due to their longterm fixed eating habits, although they felt uncomfortable for having raw fish. The findings of this study clearly present that the exposure of hazardous substances by the oil spill accident had a significant impact on changes in eating habits besides economic, physical, and mental problems among the residents in Taean. Continuous health and nutrition monitoring and support are needed.

• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.1-14
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• 1995

The purpose of this research is to assess the health risk of pollutants in drinking water and recommend the guidelines and management plans for maintaining good quality of drinking water. This study has been funded as a national project for three years from 1992 to 1995. This study(the second year, 1993-1994) was conducted to monitor 32 species of carcinogenic chemicals such as volatile organic compounds(VOCs), polynuclear aromatic hydrocarbons(PAHs), pesticides and heavy metals of drinking water at some area in six cities of Korea, and evaluate health risk due to these chemicals through four main steps of risk assessment in drinking water. In hazard identification, 32 species of carcinogenic chemicals were identified by the US EPA classification system. In the step of exposure assessment, sampling of raw, treated and tap water from the public water supply system had been conducted from 1993 to 1994, and 32 chemicals were analyzed. In dose-response assessment, cancer potencies, unit risk estimates and virtually safe doses of carcinogens were obtained by TOX-RISK (Version 3.1). In risk characterization of detected chemicals, health risk due to carcinogens such as vinyl chloride, carbon tetrachloride, dichloromethane, 1, 2-dichloromethane, chloroform, benzene and arsenic of tap water in several cities exceeded 10$^{-5}$ level. We suggest that non-regulated chemicals which exceed 10$^{-5}$ excess cancer risk level, such as vinyl chloride, carbon tetrachloride and 1, 2-dichloroethane, should be monitored periodically and be regulated by the Drinking Water Management Act, and database for exposure parameter of our own situation should be established.