We studied the changes in the concentration of total volatile organic compounds generated in newly-built schools (five kindergarten schools, two primary schools, three middle schools, one high school) by the bake-out. Samples were collected in classrooms. By using the bake-out technique the removal efficiency of total volatile organic compounds was 89.1%(maximum) and 27.5%(minimum). By using this bake-out technique the removal efficiency was 42.5% greater than the ventilation method. Therefore, we determined that it is appropriate to apply both the bake-out and ventilation methods in the case of newly-built schools

This study was carried out to measure temperature, humidity, and bacterial concentration and species from the indoor air of a greenhouse used for shiitake cultivation. The highest level of humidity in the greenhouse was recorded at over 91.5% and the lowest humidity was recorded at 50% during 12 months. Temperature was between 5.1-30.5oC except for January. These results indicate that bacteria can survive in the indoor air of the greenhouse. Total bacterial concentration exceeded the Korean indoor air quality standard value (8.0 × 102 cfu/m3) in winter. A total of 13 genera and 17 species were isolated and identified from the indoor air of the greenhouse. Especially, 3 species (Kocuria rosea, Staphylococcus xylosus and Curtobacterium flaccumfaciens) have been reported to affect on human health. This is first report of airborne bacteria in a greenhouse used for shiitake cultivation.

In order to evaluate the quality of indoor air due to the remodeling and newly-built in S City, 60 schools wereinvestigated in formaldehyde (HCHO) and total volatile organic compounds (TVOCs). One school exceeded thenational standard of formaldehyde 100µg/m³ at 1st measurement. Thirty-eight schools showed higher level ofTVOCs over 400µg/m³ at 1st measurement. Twelve schools showed higher level of TVOCs over 400µg/m³ at2nd measurement. This result derived from TVOCs which originated from the building materials and finishingmaterials. To prevent the pollution of indoor air quality at schools caused by formaldehyde and TVOCs, therecommendation of environmentally-friendly building materials, the diminishment of emission by bakeout process,the efficient combination of natural ventilation and mechanical ventilation, and antibacterial effect of chemicalcontrol measures as photo-catalysts should be given positive investigation.

Recent years, shiitake cultivation using sawdust medium is increasing in Korea. The cultivation is performed in mainly greenhouses. One of major concerns in shiitake cultivation is the contamination of molds which cause damages and spoil the cultivation medium and/or inhibit the growth of shiitake mycelia in the medium. Although the harmful effects of molds are boradly recognized, there is no mush data on the source of molds contamination. This study was undertaken to check what fungi exist in indoor air of vinyl greenhouse used for shiitake cultivation. During last seven months period, we sampled air in two different vinyl greenhouses located in Cheongyang-gun, and Jangheung-gun, respectively. temperature and humidity average of a vinyl greenhouse located in Cheongyang-gun was 23.2℃ and 52.3% during spring season, and 26.3℃ and 79.1% during summer season. While, temperature and humidity average of vinyl a greenhouse located in Jangheung-gun was 21.4℃ and 61.7% during spring season and 32.8℃ and 70.9% during summer season. Seven mold species were isolated during spring season and six species during summer season from indoor air of the vinyl greenhouse located in Cheongyang-gun from season. In Janheung-gun greenhouse, seven species were isolated during spring season and four species during summer season. During the two investigated seasons, Trichoderma harzianum was dominant species in the two vinyl greenhouse air.

The children of daycare center are sensitive to indoor environmental pollution. This study was a preliminary investigation for improving the environmental and healthy quality of daycare centers. The sampling of sites in daycare centers was undertaken three times such as day-morning (10:00-12:00), afternoon (16:00-20:00), following dawn (04:00-08:00)-at 21 daycare centers located in Seoul, Korea from April, 2012 to July, 2012. The mean concentrations of TVOC were 255.2, 217.0, and 439.4 μg/m3 at morning, afternoon, and following dawn, respectively. The daycare center indoor/outdoor ratios on the most targeted volatile organic compounds were above 1.0 except that for carbon tetrachloride, which was almost 1.0. Significant correlations (p<0.01) were observed between indoor and outdoor carbon tetrachloride, which implies that indoor carbon tetrachloride could be largely accounted for by outdoor sources. The other targeted indoor volatile organic compounds such as benzene, toluene, ethylbenzene, styrene, xylenes, chloroform showed no significant correlations with that of outdoor.

Recently, airborne fungi as indoor air pollutant have attention due to its health related problems such as asthma, rhinitis, sinusitis, atopy, pneumonia, building syndrome and etc.. However, it is considered that current laws and policies in Korea are not efficient to deal with these problems. Our research investigated influential factors and species distribution on the basis of previous research related to airborne fungi issue conduced in Korea by applying meta analysis technique. We selected 15 articles containing variables affecting fungi population such as outdoor air characteristics, temperature, location, and ventilation to evaluate significant factors. It was confirmed that airborne fungi level has partial correlation to those factors despite of limited sample size. It is required that the consistent and systematic research effort should be extended to characterize health effect caused by these fungi as well as to control them efficiently.

This study was performed to investigate the distribution of indoor air pollutants in medical facility in Gyeonggi-do area from February to November, 2012, and to conduct the health risk assessment from obtained data. PM10, CO₂, formaldehyde, CO, and total bacteria count(TBC) did not exceed the maintained standards, but mean concentration of TVOC was 402.3 ㎍/㎥ and thirteen of them exceeded the recommended standard. In the concentration distribution of pollutants for the monthly samples, CO₂, formaldehyde, TVOC, TBC were the highest level in August. From the factor analysis of indoor air pollution provided three factors; the first factor was seasonal factor (indoor temperature and humidity, TBC and formaldehyde), the second factor was ventilation factor (CO₂, PM10 and CO), and the third factor was building(or interior) factor (TVOCs). In the health risk assessment results, the excess carcinogenesis of formaldehyde for resonable maximum exposure worker was 1.21×10-⁴ which means exceeding the cancer criteria(1.0×10-⁴). We confirmed the probability of health effect caused by TVOC. The lifetime excess cancer risk of carcinogens(benzene, formaldehyde) and hazard quotient of non-carcinogens(toluene, ethylbenzene, xylene, styrene), and risk of regulation substances(PM10, CO₂) were safety level for inpatients and out patients.

We estimated decreasing rate of indoor air pollutants with are airborne bacteria, airborne fungi, formaldehyde, total volatile organic compounds, PM10, and PM2.5 in 10 children’s hospitals and 6 childbirth houses located in Seoul and Gyeonggi-do from November to December in 2012. Sectional period was respectively divided for operating and non-operating the air cleaners. There was a trend that concentration of surveyed pollutants in children’s hospitals and childbirth houses during operating period decreased among indoor air. We used Monte-Calro simulation to remove uncertainty and identify efficiency of eliminated pollutants such as surveyed pollutants by the air cleaners. Average efficiency of removal were 61.39 ± 21.42% for airborne bacteria, 71.77 ± 19.65% for airborne fungi, 73.37 ± 24.62% for formaldehyde, 71.20 ± 25.96% for total volatile organic compounds, 65.16 ± 23.80% for PM10, and 71.06 ± 23.97% for PM2.5.

This study investigated the effect of smoking on Indoor Air Quality in smoking allowed buildings. Total 26 buildings(Restaurants 3, Billiards 4, Karaokes 6, Golfs 7, Pubs 6) were surveyed for nicotine, PM₁₀, CO₂, CO, NO₂, HCHO, TVOCs, benzene, toluene, ethylbenzene, styrene and xylene at quiet and busy time, respectively. The concentrations of nicotine, PM₁₀, CO₂ and benzene were significantly higher(p<0.05) at busy time compared to the quiet time. Some buildings exceeded Indoor Air Quality Standards for PM₁₀, CO₂, HCHO and TVOCs. Our results show that smoking-ban legistration should be introduced to improve Indoor Air Quality.

Particle collection efficiency and air cleaning capacity were tested for the two-stage electrostatic precipitator for use in indoor air cleaning systems. A wire-plate type ionizer was used as a particle charger and a dielectric film consisted of polypropylene (or polyethylene) coated metals and zigzagged metal electrodes was used as a particle collector in the electrostatic precipitator. Both particle collection efficiency and air cleaning capacity increased as increasing the applied voltage on the charger and the collector, and furthermore, as increasing the collector film width (i.e. collection area). Air cleaning capacities estimated by the product of particle collection efficiency and air flow rate were quite well consistent with the experimental ones with a proportional constant of 0.964. Ozone concentrations emitted from the charger at the applied voltages of 5.0 and 5.2 kV were less than 0.05 ppm, indoor ozone standards of UL 867-2002, KS C 9314 and SPS-KACA002-132. For the air flow rate of 11.7 m³/min, the applied floor area of 48.2 m² could be obtained when 5.2 kV and 6.0 kV were applied on the ionizer and the collector, respectively and the collector of two 15 mm polyethylene dielectric films was used.

본 연구는 유가상승에 따른 온실의 경영비 절감과 적설지역의 적설재해를 경감시키기 위하여 온수배관을 이용한 난방효과 및 온실곡부의 온도 상승효과를 구명하고자 수행되었다. 전체적으로 실험구의 온도가 대비구 보다 약 2.0~6.0℃정도 높게 나타났다. 천창부직포를 개방한 경우, 최저온도가 약 3.0~12.0℃범위로 나타나 적극적인 난방을 하게 되면 적설피해도 어느 정도 예방할 수 있을 것으로 판단되었다. 온실 내부의 높이별 온도 차이는 미미한 것으로 나타났다. 재배작물에 따른 온실의 최대난방부하는 각각 약 37,000 kcal·h-1 및 41,700 kcal·h-1정도이었다. 실험기간동안 최저 외기온 -11.9~4.0℃ 범위에서 설정온도별 발열량은 95,000~322,000 kcal 정도로서 시간당 6,050~20,900 kcal·h-1정도의 범위에 있었고, 최대난방부하와 비교하면 약 15~56%정도의 난방에너지를 공급할 수 있을 것으로 나타났다. 그리고 실험기간동안 전체 발열량과 소비전력량은 각각 2,629,025 kcal 및 677.3 kWh이었다. 화석연료인 경유로 난방 할 경우, 실험기간동안 소요되는 소비량은 291L 정도이었고, 비용은 331,700 won인 것으로 나타났다. 전력사용에 대한 총비용은 24,400 won정도로서 경유 소비 비용의 7.5%정도로 나타났다. 또한 전체 소비전력량을 에너지로 환산하면 약 582,200 kcal이고, 이 에너지는 전체 발열량의 약 22%에 불과하였다.

This study was performed in the 175 selected child-care facilities in the urban area (Seoul, Suwon, Daejeon, and Busan) and the industrial complex area (Sihwa and Yeosu) to measure of the characteristics of VOCs in the indoor air from August, 2007 to April, 2008. All samples were collected at the indoor and outdoor places to the child-care facilities in spring, summer, and winter seasons using the Tenex absorption trap and were analyzed through the GC/MSD. The mean concentration of VOCs in the 175 child-card facilities showed the highest levels of 73.68 ㎍/m³in the toluene and the lowest levels of 0.28 ㎍/m³in the chlorobenzene. In the concentration of the TVOC, it exceeded 2.5 times more as the indoor air quality guideline in Korea. The result of this study was found that the concentration of VOCs in the child-care facilities in Korea may influenced from the some factors such as the constructional period, traffic density, and ventilation rate. These findings may expected to imply that effective risk management strategies should be applied to minimize the public health effects for children in the child-care facilities in Korea.

The purpose of this study was to assess an alternative method to characterize indoor environmental factors by multiple indoor and outdoor measurements. Using a mass balance model and regression analysis, penetration factor and source strength factor were calculated using multiple indoor and outdoor measurements. This study was performed in 30 selected apartments in Seoul, Asan, and Daegu area which were constructed within 4 years and over 4 years, to measure the concentration of NO₂ from July, 2004 to September. The results of this study are as follows. The average concentration of NO₂ in Seoul, Asan, and Daegu area in the apartment constructed within 4 years are nitrogen dioxide 48.01㎍/m³ and in the apartment over 4 years are nitrogen dioxide 46.54㎍/m³. Mean ratios of indoor to outdoor NO₂ concentrations are Seoul 0.99, Asan 0.83, Daegu 1.18. The deposition constant and the source strength of NO₂ were 0.97±0.55 hr-1 and 16.33±12.30 ppb/h, respectively. In conclusion, indoor environmental factors were effectively characterized by this method using multiple indoor and outdoor measurements.

Indoor, outdoor, and personal nitrogen dioxide (NO₂) exposures were studied in a population of housewives. Daily Indoor and outdoor NO₂ concentrations were measured and compared with simultaneously personal exposures of 17 housewives for 7 consecutive days in 17 houses. In this study, indoor and outdoor NO₂ samples at home were collected only while the housewives were at home samples. Time activity patterns and house characteristics were used to determine the effects of these factors on personal exposure. Since housewives spent their times in indoor houses with mean of 78.3%, their NO₂ exposures were associated with indoor houses NO₂ levels (r= 0.89) rather than outdoor NO₂ level (r= 0.85). Contribution of indoor NO₂ concentration on personal exposure was estimated by 70.77% by using of mass balance model. The close association between measured indoor NO₂ concentrations and measured personal exposure and contribution of indoor NO₂ concentration suggests that measuring indoor concentrations of NO₂ in the home is sufficient to estimate personal exposure accurately.

The aim of this study is to estimate and compare indoor air quality(IAQ) at stock rooms in general library and in National Archives and to provide fundamental data in order to enact the law on management of IAQ at stock rooms in general library. The survey of IAQ in stock rooms was performed in Seoul National Archives in August 2009, and the basic data on level of indoor air pollutants in stock rooms at general library was collected from domestic journal. The concentration of NO₂ was 114.1 ppb at audiovisual documentary stock rooms in National Archives. That value exceeded 50 ppb guideline that was legislated by the Korean Ministry of Public Administration and Security. The concentration of PM₁₀ and VOCs were 59±9㎍/m³ and 367±83㎍/m³, respectively at stock rooms in general library. These values were exceeded from the guideline of Korean Ministry of Public Administration and Security that is 50㎍/m³ for PM₁₀ and 400㎍/m³ for VOCs. Also, the exceeded probability from the guideline was 83.7% in PM₁₀ and 35.6% in VOCs. Therefore, we suggest that a national plan for the management of IAQ at stock rooms in general library should be established.

This study investigated the indoor air concentrations and the harmful effects on health by hazardous pollutants in the normal classrooms and special classrooms of 132 elementary, middle, and high schools located in 13 sites in Chungnam from February 2006 to June 2007. The results obtained from this investigation are as follows. As the results of the survey on the indoor air quality, volatile organic compounds were higher in normal classrooms(251.67㎍/m³) than special classrooms (181.59㎍/m³), and formaldehyde was significantly higher in special classrooms (34.22㎍/m³) than normal classrooms (24.61㎍/m³). With regards to the differences of pollutant distribution among elementary, middle, and high schools, volatile organic compounds were the highest in elementary schools (210.79㎍/m³) followed by middle schools (207.79㎍/m³) and high schools (195.96㎍/ m³), and formaldehyde was the highest in high schools (36.03㎍/m³) followed by elementary schools (29.84㎍/ m³) and middle schools (29.16㎍/m³). With regards to the mean concentration of pollutants by school building age, VOCs were the highest in less than 1 year old classrooms (410.93㎍/m³), followed by less than 3 years old classrooms (156.52㎍/m³) and less than 2 years old classrooms (120.18㎍/m³). Formaldehyde was also investigated to be significantly higher in less than 1 year old classrooms (41.37㎍/m³) than 2 or 3 years old classrooms (31.50㎍/m³, 22.21㎍/m³, respectively).

In order to capture the indoor CO₂ gas from public indoor spaces, a commercial zeolite(4A) was modified with alkali metals useful for adsorption. The prepared sorbents showed somewhat improved adsorption capacity. A few isotherm models were reviewed to characterize the adsorption mechanism of test sorbents. Sips model was found the most appropriate for low level indoor CO₂ adsorption, but revealed a significant error in low pressure regimes and required numerical analysis for quantitative evaluation. Thus, a parameter(qm) in the equation was empirically recorrelated with a operation temperature. As a result, the final model equation including a simple linear function presented less errors for evaluation of the potential capacity of adsorption.

To research indoor air pollution in the training rooms of technical high school, the temperature, air current, humidity, CO₂, CO, O₃ were measured by Indoor Climate System(ICS 500, Casella, UK) at each classroom, scientific laboratory, electricity training room, electronic equipment training room and welding training room. The change of air pollution concentration and its correlation were additionally compared and analyzed. At closed small space such as classroom, scientific laboratory, electronic equipment training room and electricity training room, the CO₂ concentration was obtained to the 2,030ppm(max.), which is higher than notified and recommended standard value(1,000ppm) by Ministry of Health and Welfare and Ministry of Environment, Korea. At welding training room where is larger and more ventilated than general classroom, CO concentration was measured to the 3.6ppm, which is higher than average 1ppm measured at other training rooms. The concentration of O₃ is not yet regulated from the standards of underground air quality, but at welding training room it was measured as 0.11ppm(max.) that is higher than 0.01ppm measured at other training rooms. The higher value of temperature, air current, radiant temperature and CO₂ concentration was shown at scientific laboratory, electricity training room and electronic equipment training room where are closed and same with the scale of classroom. And the higher concentration of CO₂, CO and O₃ was shown at welding training room which was opened larger classroom. The indoor air pollution by CO₂, CO and O₃ may directly affect on the training room where many students work at a small space, and they should be controlled appropriately. Each experimental formulas were made for the estimation of CO₂, CO and O₃ concentration depending on some kinds of variables at each training room. It is found that indirect ventilation system with a filter will be needed for regular and constant ventilation and the ventilation system should be applied to protect and make clean and comfortable environment of training rooms at technical high school.

Indoor air quality can be affected by indoor sources, ventilation, decay and outdoor levels. Although technologies exist to measure these factors, direct measurements are often difficult. Toluene and nitrogen dioxide (NO₂) concentrations of residential indoor and outdoor were simultaneously measured and compared in 16 houses, using passive samplers during every 3 days for 60 days. Concentrations of toluene and NO₂ were analyzed by gas chromatography and spectrophotometer, respectively. Using a mass balance model, penetration factor (ventilation rate divided by sum of ventilation rate and deposition constant) and source generation factor (source generation rate divided by sum of ventilation rate and deposition constant) were calculated by multiple indoor and outdoor measurements. The mean contributions of toluene of indoor and outdoor sources on residential indoor air quality were estimated to be 31.01% and 67.00%, respectively. On the other hand, mean contributions of NO₂ were 58.93% and 41.06%, respectively. These results could be explained that contributions of indoor and outdoor air pollutants sources are different to residential indoor air concentrations. In conclusion, contributions of outdoor air and indoor sources affecting indoor air quality were effectively characterized using multiple indoor and outdoor measurements.

This paper presented experimental results for photocatalytic air cleaner removal performance for malodorous compounds generated from rest room. Photocatalytic oxidation (PCO) efficiency was up to 80∼ 90% for NH₃ in chamber, 29.3% for H2S, 79.6% for CH3SH, 58.8% for DMDS individually. PCO efficiency for DMS(Dimethy Sulfide) and DMDS(Dimethyl Disulfide) were relatively lower than that of NH₃ and CH3SH, this results indicate that DMS and DMDS removal process were effected by by-products of photocatalytic oxidation and humidity. Ozone was relatively low (below 5ppb) under the test conditions through photocatalytic oxidation. It is necessary to test a reliability of the air cleaner for a longtime under the various indoor conditions. But, prototype photocatalytic air cleaner will promise useful air cleaner for indoor air quality applications.