• Journal of Environmental Science International
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• v.15 no.10
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• pp.929-933
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• 2006

Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time Indoors. Especially when indoor environments have sources of contaminants, exposure to in-door air can potentially pose a greater threat than exposure to ambient air. In this study, estimations of volatile organic compounds and formaldehyde omission rate in indoor environments of new apartments were carried out using mass balance model in indoor environment, because indoor air quality can be affected by source generation, outdoor air level, ventilation, decay by reaction, temperature, humidity, mixing condition and so on. Considering the estimated emission rate of volatile organic compounds and formaldehyde, it Is suggested that new apartment should be designed and constructed in the aspect of using construction materials to emit low hazardous air pollutants.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.261-262
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• 2003

현대인들은 하루 중 80∼90％ 이상의 많은 시간을 실내에서 생활하고 있어 실내에서의 발생되는 오염물질에 대한 특성파악은 무엇보다도 중요하다. 실내오염물질의 종류와 발생원은 매우 다양하며, 최근에는 산업발달과 더불어 수 많은 종류의 새로운 복합화합물질들이 발생되고 있다. 신축건물에 사용되는 건축자재는 휘발성유기화합물(VOCs)과 포름알데히드(HCHO)등의 다양한 유해화학물질들을 방출하고 실내공기질을 악화시키는 것으로 조사되고 있다. (중략)

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.612-618
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• 2023

Modern society spends more than 80% of its daily life indoors, emphasizing the need for attention to indoor air pollution due to the improvement in living standards. In this study, the performance and reaction characteristics of the Pt/TiO₂ catalysts prepared by liquid-phase reduction for the removal of formaldehyde (HCHO), one of the indoor air pollutants, at room temperature without the need for additional light or heat were investigated. As a result, it showed that catalysts prepared by the same method showed approximately 40~80% various activities depending on the type of TiO₂. XRD, BET, and XPS analyses were performed to investigate the particle size, crystal structure, specific surface area, and O/Ti molar ratio of the support material, and it revealed that the correlation between the properties and performance was insignificant. To explore the oxidation reaction pathway of formaldehyde (HCHO), in situ DRIFT analysis using carbon monoxide and H₂-TPR was perfomed. The results revealed that the performance was demonstrated by the oxidation state of the active metal and the adsorption-desorption characteristics of the adsorbate species.

• Journal of environmental and Sanitary engineering
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• v.24 no.2
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• pp.1-8
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• 2009

This study was conducted at a Terminal, a Parking Lot, an Underground shopping center, a Funeral hall and a Hospital waiting room of Cheon An area in August 2008 to examine the concentration level of HCHO(formaldehyde). The concentration level of the remodeled sites were $39.4\;{\pm}\;12.0\;{\mu}g/m^3$ in the terminal, $32.7\;{\pm}\;7.3\;{\mu}g/m^3$ in the parking, and $97.8\;{\pm}\;29.4\;{\mu}g/m^3$ in the underground shopping center. The underground shopping center had the highest level and followed by the terminal and the parking. On the contrary, the site remodeling had the level of $17.7\;{\pm}\;12.4\;{\mu}g/m^3$ in the funeral hall and $17.9\;{\pm}\;0.6\;{\mu}g/m^3$ in the hospital waiting room. The funeral hall had highest level than that of the hospital waiting room. Both the remodeled sites and the not remodeled site had concentration level of HCHO below the standard level, but it was higher in the remodeled sites. There were no relations among the HCHO, the temperature and the humidity in facilities of Cheon An area.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.287-290
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• 2006

The purposes of this study were to make clear the present condition of the TVOC and HCHO concentration after remodeling in apartment houses and to analyze the relation of concentrated ascension and remodeling elements. The field measurements of TVOC and HCHO concentration were carried out in 4 subject apartment houses according to the Korea Test Method Standard for Indoor Air Quality. The results are as follows; the TVOC concentration after remodeling ranged from mean 0.35ppm to mean 5.08ppm and increased of 0.35$^{\sim}$5.08ppm. The concentration of 3 subjects exceeded the Indoor Air Quality Management standard for the newly-built apartment houses (0.7ppm). The HCHO concentration after remodeling ranged from mean 0.13ppm to mean 0.43ppm and increased of 0.06$^{\sim}$0.26ppm. The concentration of 2 subjects exceeded the Standard (0.16ppm). As results of analysis on the relation of concentrated ascension and remodeling elements, the amount and the types of finishing materials and adhesives affected concentrated ascension. Also, production method for installed or purchased furniture had certain effect on the TVOC and HCHO concentration ascension.

• Korean Journal of Human Ecology
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• v.18 no.6
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• pp.1363-1374
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• 2009

The purpose of this study was to determine the actual state of the indoor air quality in newly built or remodeled kindergartens by TVOC and HCHO concentration and teachers' responses. The field measurements on the levels of TVOC and HCHO were carried out in six classrooms of newly built or remodeled kindergartens before their opening. The interviews with teachers of subject kindergartens were carried out at the end of the first semester. The contents of the interviews were teachers' subjective responses and symptoms of the kindergarten pupils on the Sick New-School Syndrome. The results are as follows; the mean value of TVOC concentration in the classrooms of kindergartens ranged from 0.10ppm to 0.42ppm, which can theoretically exert a harmful influence on residents. The mean value of HCHO concentration ranged from 0.00ppm to 0.03ppm, which does not exceed the standard. The TVOC concentrations of the more ventilated kindergartens were lower than the others. Also, the classrooms with high concentrations of TVOC showed negative responses or symptoms in teachers and kindergarten pupils.

• Korean Journal of Remote Sensing
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• v.31 no.6
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• pp.523-530
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• 2015

A Multiple Regression Method (MRM) is used for the first time with Ozone Monitoring Instrument (OMI) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to estimate formaldehyde (HCHO) Vertical Column Density (VCD). For a 3.5-year period from January 2005 through July 2008, HCHO VCD estimation is investigated in cities over Asia in two categorized areas: (1) Major cities in Northeast Asia (Beijing, Seoul, and Tokyo), (2) Major cities in Southeast Asia (New Delhi, Dhaka, and Bangkok). In the Major cities in Northeast Asia, there are good agreements between HCHO estimated by the multiple linear regression method ($HCHO_{MRM}$) and HCHO measured by OMI ($HCHO_{OMI}$) (0.78 < $R^2$ < 0.82). However, in Major cities in Southeast Asia, there were poor agreements between $HCHO_{OMI}$ and $HCHO_{MRM}$ (0.24 < $R^2$ < 0.39). In addition, an unbiased assessment of the MRM performance using modeling and validation groups shows that the performance of the MRM based on separate modeling and validation groups is comparable to that using all the data for deriving Multiple Regression Equations (MREs). This study demonstrates that MRM can be an alternative tool for HCHO estimation in certain areas over Asia.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.255-260
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• 2008

The purposes of this study were to determine the actual state of the indoor air quality by TVOC concentration and residents' responses and to analyze the influencing factors of IAQ in newly built university dormitory. The field measurements on the levels of TVOC and HCHO were carried out three times at an interval of 4 weeks in 3 rooms of a dormitory. The questionnaire survey on the residents that inquired into the lifestyle, the consciousness related to IAQ, and the responses of SHS was fulfilled. According to the results, the level of TVOC was approximately $0.14{\sim}18.5ppm$ and HCHO was $0.23{\sim}6.89ppm$ during 3 month since construction completion, which are seriously in excess of standard level, and seemed to be on the decrease as time goes by. The factors influencing the differences of the levels of TVOC or HCHO were the amount of ventilation including infiltration, heating temperature, relative humidity, or the use of living things including chemical. However, the residents rarely felt the responses of SHS and did not be conscious of the importance of ventilation.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.135-143
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• 2009

The purposes of this study were to determine the actual state of the indoor air quality by measuring TVOC Concentration and surveying residents' responses in a newly built university dormitory and to analyze the influencing factors of IAQ. Field measurements on the concentrations of TVOC and HCHO were carried out three times at 4 week intervals in 3 rooms of a dormitory. A questionnaire survey was conducted on residents which inquired into the resident's lifestyle, their consciousness of IAQ, and the responses to SHS. According to the results, TVOC concentrations were 0.14~18.5 ppm and HCHO concentrations were 0.23~6.89 ppm during the 3 months following the completion of construction, showing a serious state in which standard levels are exceeded, though these levels seemed to decrease over time. The factors influencing the differences in the levels of TVOC and HCHO were the ventilation volume including infiltration, the heating temperature, relative humidity, or the use of living matter that include chemical ingredients. However, the residents rarely felt the symptoms of SHS and were not conscious of the importance of ventilation.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.751-762
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• 2015

This study was performed to investigate the stability of soil moisture in controlling air ventilation rate within a horizontal biofilter, and to compare removal efficiency (RE) of indoor air pollutants including fine dust, volatile organic compounds (VOCs), and formaldehyde (HCHO), depending on whether dieffenbachias (Diffenbachia amoena) were planted in the biofilter. The relative humidity, air temperature, and soil moisture contents showed stable values, regardless of the presence of D. amoena, and the plants grew normally in the biofilter. REs for number of fine dust particles (PM10 and PM2.5) within the biofilter filled with only soil were at least 30% and 2%, respectively. REs for number of fine dust particles (PM10 and PM2.5) within the biofilter including the plants were above 40% and 4%, respectively. RE for fine dust (PM10) weight was above 4% and 20%, respectively, in the biofilter containing only soil or soil together with plants. In the case of the biofilter filled with only soil, REs for xylene, ethylbenzene, toluene or total VOC (T-VOC) were each more than 63%; however, REs for benzene and formaldehyde (HCHO) were above 22% and 38%, respectively. In the biofilter with the plants, REs for xylene, ethylbenzene, toluene, and T-VOC were each above 72%, and REs for benzene and HCHO were above 39%. Thus, RE of the biofilter integrated with plants was found to be higher for volatile organic compounds than for fine dust. Hence, the biofilter was very effective for indoor air quality improvement and the effect was higher when integrated with plants.