• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.145-152
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• 2001

The purpose of this study was to determine nitrogen dioxide(NO$_2$) decay rate by reaction between NO$_2$ and interior materials in Korean residence. The results of this research could be helpful to choose the interior construction materials and to study on reduction of indoor air pollutants. The results of this research are as follows; For 30 residences in Seoul and Incheon from October 2000 to march 2001, the mean of infiltration rate was 0.70$\pm$0.44 ACH, and single-detached houses (7 houses) and apartments (19 houses) were 0.97$\pm$0.55 ACH and 0.61$\pm$0.34 ACH, respectively. The $CO_2$ decay followed approximately first-order process ($R^2$=0.97$\pm$0.02). There existed a statistic significance in filtration rate between houses built in 1980’s and built in 1990’s by t-test (p<0.02). Mean of NO$_2$ decay rates in 26 residence3s except 4 residences was 0.94$\pm$0.49hr$^{-1}$ , and also 0.86$\pm$0.49hr$^{-1}$ , 0.97$\pm$0.50hr$^{-1}$ in single-detached houses and apartments, respectively. Mean NO$_2$ decay rates in houses built in 1980’s were 0.78$\pm$0.37hr$^{-1}$ , 1.33$\pm$1.03hr$^{-1}$ , respectively. Nothing were showed statistical significance among indoor temperature, indoor humidity, and NO$_2$ decay rate. However, NO$_2$ decay rates had a tendency to increase by increase of temperature and humidity. Average volume/surface of participated houses was 0.55$\pm$0.07m and mean NO$_2$ deposition velocity was calculated as 1.46$\pm$0.59msec$^{-1}$ .

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.5
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• pp.543-553
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• 2010

Almost five million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan. As the subway system is typically a closed environment, indoor air pollution problems frequently occurs and passengers complain of mal-health impact. Especially $PM_{10}$ is well known as one of the major pollutants in subway indoor environments. The purpose of this study was to compare the indoor air quality in terms of $PM_{10}$ and to quantitatively compare its source contributions in a Seoul subway platform before and after installing platform screen doors (PSD). $PM_{10}$ samples were collected on the J station platform of Subway Line 7 in Seoul metropolitan area from Jun. 12, 2008 to Jan. 12, 2009. The samples collected on membrane filters using $PM_{10}$ mini-volume portable samplers were then analyzed for trace metals and soluble ions. A total of 18 chemical species (Ba, Mn, Cr, Cd, Si, Fe, Ni, Al, Cu, Pb, Ti, $Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${SO_4}^{2-}$) were analyzed by using an ICP-AES and an IC after performing proper pre-treatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the source of particulate matters. $PM_{10}$ for the station was characterized by three sources such as ferrous related source, soil and road dust related source, and fine secondary aerosol source. After installing PSD, the average $PM_{10}$ concentration was decreased by 20.5% during the study periods. Especially the contribution of the ferrous related source emitted during train service in a tunnel route was decreased from 59.1% to 43.8% since both platform and tunnel areas were completely blocked by screen doors. However, the contribution of the fine secondary aerosol source emitted from various outside combustion activities was increased from 14.8% to 29.9% presumably due to ill-managed ventilation system and confined platform space.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1306-1312
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• 2011

Underground Subway station's air pollutants are introduced from the indoor or outdoor. And Radon is a major pollutant in the subway station. Radioactive substances Radon is occuring naturally in granite tunnel wall and underground water. Especially inert gas Radon that causes lung cancer in human is anywhere but 5678 S.M.R.T. tunnels deep and pass through the granite plaque have a lot of Radon. The Radon concentration is determined by the following reasons : radon content of soil and concrete, underground water, ventilation, pressure difference, building structure, temperature, etc. So Radon concentration is hard to predict. And we can't only ventilate owing to era of high oil prices. This study focuses on our efforts for the reduction of Radon concentration. And the purpose is to provide basically datas of specially managed 15 subway station's Radon concentration.

• Journal of the Korean Solar Energy Society
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• v.23 no.4
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• pp.81-88
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• 2003

Earth friendly system is applied widely to industries for maintaining development. The declaration of earth friendly characteristic which is an indication of the total amount of energy in evaluation of earth friendly material is not easy to apply to building materials Therefore, Accurate standards about earth friendly materials are necessary. Earth friendly building materials should be considered in the fields of energy and resource consumption, changes in urban climate and resident health, etc. Among these fields, energy and resource consumption has released toxic pollutants into the air, caused indoor moisture problems and exhausted resources continuously. Especially, moisture problem is an indicator of main factors of earth friendly characteristic. Timber, Soil. Cement Mortar and Charcoal are used to examine the sustainable properties of materials of moisture control. The result shows that wood, charcoal and soil is vivid in changes of moisture absorption and discharge in comparison with that of cement mortar.

• Journal of Forest and Environmental Science
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• v.25 no.3
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• pp.147-155
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• 2009

Higher plants provide valuable genetic assay systems for screening and monitoring environmental pollutants. They are now recognized as excellent indicators of mutagenic effects of environmental chemicals and are applicable for the detection of environmental mutagens both indoor and outdoor. 2,4-dichlorophenoxyacetic acid (2,4-D) is a herbicide commonly used in agriculture. The residues of 2,4-D are present in air, water, soil and edible plants. It constitutes a real hazard to the public health because it's wide spread use in agriculture. Genotoxic effects of 2,4-D on plant cells and potential of higher plants as a biomonitoring system for detecting chemical mutagens are evaluated. It is recommended that higher plant systems have been accepted by regulatory authorities as an alternative biomonitoring system for the detection of possible genetic damage resulting from pollution and the use of environmental chemicals.

• Environmental Engineering Research
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• v.13 no.4
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• pp.171-176
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• 2008

Studies on visible-light-driven photocatalysis of air pollutants at indoor air quality (IAQ) levels have been limited. Current study investigated visible-light derived photocatalysis with N-doped and S-doped titanium dioxide ($TiO_2$) for the control of benzene at indoor levels. Two preparation processes were employed for each of the two types of photocatalyst: urea-Degussa P-25 $TiO_2$ and titania-colloid methods for the N-doped $TiO_2$; and titanium isopropoxid- and tetraisopropoxide-thiourea methods for the S-doped $TiO_2$. Furthermore, two coating methods (EDTA- and acetylacetone-dissolving methods) were tested for both the N-doped and S-doped $TiO_2$. The two coating methods exhibited different photocatalytic degradation efficiency for the N-doped photocatalysts, whereas they did not exhibit any difference for the S-doped photocatalysts. In addition, the two doping processes showed different photocatalytic degradation efficiency for both the S-doped and N-doped photocatalysts. For both the N-doped and S-doped $TiO_2$, the photocatalytic oxidation (PCO) efficiency increased as the hydraulic diameter (HD) decreased. The degradation efficiency determined via a PCO system with visible-light induced $TiO_2$ was lower than that with UV-light induced unmodified $TiO_2$, which was obtained from previous studies. Nevertheless, it is noteworthy that for the photocatalytic annular reactor with the HD of 0.5 cm, PCO efficiency increased up to 52% for the N-doped $TiO_2$ and 60% for the S-doped $TiO_2$. Consequently, when combined with the advantage of visible light use over UV light use, it is suggested that with appropriate HD conditions, the visible-light-assisted photocatalytic systems can also become an important tool for improving IAQ.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.291-295
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• 2011

A bake-out process using auto switchgear for five days was performed to evaluate the reduction effect of the concentration of volatile organic compounds (VOCs) and formaldehyde in a newly-built elementary school gymnasium. Reduction rates of VOCs were observed as followings: 38.2, 64.2, 86.3, 80.2, and 71.5% for benzene, toluene, ethylbenzene, xylene, and styrene, respectively, which satisfies the indoor air quality standards of newly-built apartment houses in Korea. The reduction rate of total VOCs and formaldehyde were 67.0 and 24.7%, respectively. Those results proved that the bake-out process using auto switchgear was effective for reducing indoor air pollutants.

• Journal of Preventive Medicine and Public Health
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• v.56 no.3
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• pp.255-263
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• 2023

Objectives: The study investigated the association between indoor air pollution (IAP) and risk factors for acute respiratory infection (ARI) symptoms in children under 5 years of age. Methods: A cross-sectional study was conducted using data derived from Indonesia Demographic and Health Survey in 2017. Binary logistic regression modeling was employed to examine each predictor variable associated with ARI among children under 5 years of age in Indonesia. Results: The study included a total of 4936 households with children. Among children under 5 years old, 7.2% reported ARI symptoms. The presence of ARI symptoms was significantly associated with the type of residence, wealth index, and father's smoking frequency, which were considered the sample's socio-demographic characteristics. In the final model, living in rural areas, having a high wealth index, the father's smoking frequency, and a low education level were all linked to ARI symptoms. Conclusions: The results revealed that households in rural areas had a substantially higher level of reported ARI symptoms among children under 5 years old. Furthermore, the father's smoking frequency and low education level were associated with ARI symptoms.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.294-301
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• 2013

The particle matter concentrations in the subway stations should be monitored and controlled for the health of commuters on the subway system. Seoul Metro and Seoul Metropolitan Rapid Transit Corporation are measuring several air pollutants regularly. In this paper, the reliability of the cheap instruments using light scattering method is improved with the help of a linear regression analysis technique to measure the $PM_{10}$ concentrations continuously in the subway stations. In addition, a monitoring system is implemented to display and record the data of $PM_{10}$, $CO_2$, humidity, and temperature. To transmit and receive these measured sensor data, CDMA M2M wireless communication method is applied.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.889-894
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• 2008

Exhaust system used in toilet and cooking place of high riser public house is roof fan of two basic types : natural roof ventilator and natural/forced roof ventilator. Natural/forced roof ventilator has a motor in the rotary shaft. There are many high riser public house in Korea. These buildings were not viewed as being major contributors to exhaust pollutants producted in indoor. It was because many engineers thought that exhaust in high riser building depend on stack effect. This study investigates on stack pressure determined by exterior pressure and the difference pressure control in exhaust stack used in high riser public house. This paper focuses mainly on the effect of the time interval for power supply of motor installed in roof fan with function of natural wind velocity and of exhaust air volume of toilet. It is observed there are higher exhaust efficiency than the existing natural roof ventilator.