• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.997-1001
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• 2006

Organic compost has been widely applied to the cropland because it has been thought as Environmentally Sound Agriculture (ESA) in Korea. In this study, two-year indoor rainfall experiments were performed. Surface runoff and groundwater volume from 10% and 20% slope plots were measured and water quality samples were collected and analyzed for BOD, COD, T-P and T-N. Flow weighted mean concentration (FWMC) values were computed to assess effects of various fertilizer treatments. FWMC BOD values for organic compost treated plots were higher than chemical fertilizer treated plots. FWMC BOD values for 20% slope plots were higher than those from those for 10% slope plots. The similar trends were found for COD and T-P. FWMC T-N values for chemical fertilizer treated plots were higher than organic compost treated plots. FWMC T-N values for 10% slope plots were higher than those for 20% slope plots. In Korea, excessive use of organic compost has caused extremely high levels of organic matter contents at the cropland. Since organic compost is very slow in releasing its nutrients to the soil, farmers usually apply excessive organic compost for immediate effects and maximum crop yields, which has been causing soil and water quality degradations. Therefore, thorough investigations for better nutrient management plans are needed to develop the ESA strategy in Korea.

• Journal of Distribution Science
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• v.17 no.7
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• pp.65-76
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• 2019

Purpose - The purpose of this study is to investigate economical ventilation effectiveness to reduce hazardous materials exposure and damage of workers by analyzing exposure amount of noxious substances under various ventilation conditions of nail salon for indoor environments. Research design, data, and methodology - This study was carried out with cooperation of Nail shop located in SeongNam city to involve an analysis of the environmental impact indoor air quality, pollutant exposure and economical cost-effectiveness in the nail workplace. The hazardous substances were PM-10(Particulate Matter-10㎛), VOCs(Volatile Organic Compounds) and Formaldehyde, which are the major materials of nail workplace. Results - PM-10 is reduced by about 60% with air cleaner, forced artificial ventilation by 32%, and natural ventilation by about 12%. TVOCs and Formaldehyde showed similar efficiency (80~100%) after natural ventilation and ventilation after 60 minutes. The removal efficiencies of VOCs and formaldehyde were similar to those of natural ventilation and mechanical ventilation system. However, in case of dust, natural ventilation was reduced by artificial ventilation system due to inflow of external dust during natural ventilation. Conclusions - If the pollution degree of outdoor air is not high, air volume is high, and natural ventilation is performed when the air conditioning and heating system is not operated. Even at the end of the work, it keeps operating for 60 minutes to remove the pollutants generated. Results of this analysis demonstrated that the worker environment can be improved by adopting institutional legislation and guidelines for ventilation.

• Environmental Analysis Health and Toxicology
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• v.24 no.2
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• pp.137-148
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• 2009

This study quantitatively investigated the emissions of indoor air pollutants associated with the utilization of air fresheners indoors, and evaluated individual exposure to five specified indoor air pollutants, which were chosen on the basis of selection criteria. An electrically-polished stainless steel chamber (50L) was employed to achieve this purpose. Test air fresheners were selected through three steps: first, on the basis of market sales; second, on the basis on a preliminary head-space study; and lastly, on the basis of emissions of toxic compounds (benzene, ethyl benzene, limonene, toluene, and xylene). The empirical mathematical model fitted well with the time-series concentrations in the environmental chamber (in most cases, determination coefficient, $R^2{\gtrsim}$0.9), thereby suggesting that the empirical model was suitable for testing emissions. The concentration equilibrium appeared 180 min after the introduction of sample air fresheners into the chamber. Both the chamber concentrations of emission rates or factors varied greatly according to air freshener type. It is noteworthy that although benzene, ethyl benzene, toluene, and xylene were emitted from all test air fresheners, their exposure levels were not significant enough to result in any significant health risk. However, certain type of air fresheners were observed to emit significant amount of limonene, which is potentially reactive with ozone to generate secondary pollutants with oxidants such as ozone, hydroxyl radicals, and nitrogen oxides. The exposure levels to limonene associated with the utilization of three air fresheners were estimated to be 13 to 175 times higher than that of other air fresheners. This information can help consumers to select low-pollutant-emitting air fresheners.

• Journal of Environmental Science International
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• v.18 no.10
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• pp.1123-1134
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• 2009

This study was designed to evaluate qualitatively and quantitatively the pollutant compositions, which were emitted from three types of mosquito repellents(MRs)(mat-, liquid-vaporized, and coil-type) by utilizing a 50-L environmental chamber. A qualitative analysis revealed that 42 compounds were detected on the gas chromatography/mass spectrometer system, and that the detection frequency depended upon chemical types. Nine of the 42 compounds exhibited a detection frequency of 100%. Four aromatic compounds(benzene, ethyl benzene, toluene, and xylene) were detected in all test MRs. The concentration equilibriums in the environmental chamber were achieved within 180 min after sample introduction. The coil-type MR represented higher chamber concentrations as compared with the mat- or liquid-vaporized-type MR, with respect to the target compounds except for naphthalene. In particular, the chamber concentrations of ethyl benzene, associated with the use of coil-type MR, were between 0.9 and $65\;mg\;m^{-3}$ whereas those of mat- and liquid-vaporized-type MRs we~e between 0.5 and $2.0\;mg\;m^{-3}$and 0.3 and $1.4\;mg\;m^{-3}$, respectively. However, naphthalene concentrations in the chamber, where a liquid-vaporized-type MR was placed, were measured as between 17.8 and $56.3\;mg\;m^{-3}$, but not detected in the chamber, where a mat- or coil-type MR was placed. The empirical model fitted well with the time-series concentrations in the environmental chamber(in most cases, determination coefficient, $R^2$ ≿ 0.9), thereby suggesting that the model was suitable for testing emissions. In regards to the target compounds except for benzene, although they were emitted from the MRs, health risk from individual exposure to them were estimated not to be significant when comparing exposure levels with no observed adverse exposure levels or lowest observed adverse exposure levels of corresponding compounds. However, it was concluded that the use of MRs could be an important indoor source as regards benzene.

• Analytical Science and Technology
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• v.23 no.3
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• pp.255-260
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• 2010

The Ministry of Environment simultaneously revised testing methods and emission standards of adhesives product on the "Law of indoor air quality management" for the effective management of the building materials releasing pollutants in great quantities. Accordingly, it is impossible to compare original standards with revised standards directly. The influences of each factor of the revised testing methods of adhesive product on the emission rate of pollutants are reviewed through comparing with the original testing method. Through this study, revised pollutant emission control standards were assessed. With the result that it is found that emission rate of adhesives product is weakened two and half times by changing test period and the emission rate resulting from changing drying time has little difference. As a result of comparing TVOC emission standards with the original testing method considering the modification of testing methods, it is found that the emission standard through this revision is strengthened about 2.1 times more than that of present testing method.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.454-460
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• 2009

The subway is the major public transportation system in Seoul with 2.2 million people using it everyday. Indoor air pollution in the subway can be a significant part of population exposure because of the number of people using the subway, time spent in transit and potentially high exposure for certain pollutants. The Korea Ministry of Environment has established the level 2 of recommended standards of $PM_{10}$ and $CO_2$ in subway trains. The aims of this study were to determine the airborne levels of $PM_{10}$, $CO_2$ and any correlation between pollutant levels and number of passenger in a subway train. The airborne $PM_{10}$ and $CO_2$ were measured on the inside of trains on line #4 for 4 different days from October to November in 2008. Average $PM_{10}$ and $CO_2$ levels were $113{\pm}25{\mu}g/m^3$ and $1402{\pm}442$ ppm, respectively. These levels did not exceed the level 2 of recommended standards of $250{\mu}g/m^3$ for $PM_{10}$ and 3500 ppm for $CO_2$. $PM_{10}$ level was not correlated with the number of passengers, while $CO_2$ levels were positively correlated with the number of passengers. The findings suggested that $PM_{10}$ in subway trains may have sources other than those directly associated with the number of passengers.

• KIEAE Journal
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• v.5 no.3
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• pp.11-16
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• 2005

The recent trends of high-density and high-rise in apartment housing have caused the problems of decrease in ventilation rates and increase of indoor pollutant contaminants. SHS(Sick House Syndrome) has now become a major issue and threats the health of residents. To solve these indoor air problems, increase in ventilation rate is considered as one of the most efficient approach. Thus, the recent housing development is pursuing improvement in the site design and the layout of apartment building blocks to promote natural ventilation is now investigated as one of the fundamental solutions. This study was focused on the air flow characteristics of outdoor environment in an apartment complex to keep the pollutants out of the site. Age of air and pressure difference have been used as indices of the outdoor air quality. Four different types of apartment building layouts have been analyzed by CFD simulation. This study again selected a real apartment housing complex as a case study model. By analyzing the pressure differences between the front and rear of an apartment building block, the ventilation performance in each individual unit was evaluated, and its impact on ventilation performance is investigated by analyzing the stagnant air around the apartment building blocks. During this process, existing patterns of apartment housing layout have been evaluated, and the most appropriate site layout has been chosen to analyze the outdoor airflow patterns. Based on the analysis of airflow patterns of site layout, the possibilities of improving ventilation performance of an individual apartment housing is proposed.

• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.237-241
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• 2014

Benzene is a hazardous air pollutant, classified as carcinogenic to humans, that requires special management. Benzene exists both indoors and outdoors and the control measure of indoor benzene is different from that of outdoor benzene. The removal of indoor benzene needs to be accomplished at low temperatures (normally below $100^{\circ}C$), while outdoor benzene is usually removed at much higher temperature ($300-400^{\circ}C$) by using catalytic oxidation. This review paper summarizes the recent trend in catalytic treatment of airborne benzene, focusing on catalytic oxidation and catalytic ozone oxidation. Particular attention is paid to Mn-based catalysts for low-temperature oxidation of benzene, which are more economical than the other noble-metal catalysts. Various methods are used to generate more efficient Mn-based catalysts for benzene removal. Ozone oxidation is attracting particularly significant attention because it can remove benzene effectively below $100^{\circ}C$, even at room temperature.

• Land and Housing Review
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• v.13 no.2
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• pp.117-123
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• 2022

In this study, titanium dioxide photocatalyst was applied to the ventilation system to reduce particulate matter and nitrogen oxides (NOx), which are representative indoor harmful substances. A reaction device capable of installing an ultraviolet lamp was designed and manufactured so that the pollutant decomposition effect of the titanium dioxide photocatalyst identified through previous studies could be applied indoors. The reaction device was used on the indoor ventilation system and applied to the Mock-Up test. As a result of the Mock-up test, the NOx reduction performance according to the change in air volume once per hour and five times per hour was confirmed. As a result, it was confirmed that as the number of ventilation increases, the NOx reduction time decreases proportionally, and the reduction performance increases.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.417-425
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• 2023

Because an irradiation of 405 nm violet light could have a strong energy, it was used to be sterilized against various microbes in the indoor air condition or fresh food. Escherichia coli is a representative bio-pollutant in the indoor air-borne bacteria, and a hygienic microbe in the horticultural food. This study evaluated the inactivation influences on E. coli DS5α after exposure to 405 nm violet-light (VL) by investigating irradiating time, and the vertical and horizonal distance from light source. The illumination of 405 nm VL was inversely proportional to the distance from the VL source. E. coli DS5α on nutrient agar (NA) was inactivated approximately 50% more than the control when irradiated at 65 cm from 405 nm VL for 3 hours. When compared to the control, E. coli DS5α was inactivated approximately 50% within 70 cm from 405 nm VL for 3 hours. As it was irradiated for 3 hours 70 cm away from 405 nm VL, the horizonal distance from the point was negatively correlated to the inactivation of E. coli DS5α. These results indicated that the inactivation of E. coli DS5α grown on NA medium needs to be irradiated with 405 nm within 70 cm from the light source for 3 hours.