In order to meet the national standard and public needs for Seoul Metro subway, air purification has been taken into a consistent consideration with the addition of high quality control facilities. This work focuses on the review of the cost effectiveness to improve the air filtration of an MVAC (mechanical ventilation & air conditioning) in a field subway. The inflow PM₁₀ and PM_2.5 into the test MVAC chamber were 19.4 kg/yr and 8.9 kg/yr respectively. It corresponds to the environmental cost of 5,857,000 won for PM₁₀ and 6,608,000 won for PM_2.5 every year. While the current filtration system collects approximately 55% of the inlet PM₁₀ and 35% of PM_2.5, a new lay-out showed 80% for PM₁₀ and 55% for PM_2.5. The new design presented the environmental benefit for PM10 with 1,464,000 won, whilst the additional cost required 3,192,744 won. In the future, however, the increase of environmental benefits for the indoor dust over the atmospheric aerosols will more or less compensate the potential cost.

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).

The objective of this study was to estimate distribution of hazardous air pollutants and volatile organic compounds at diverse indoor areas in school. The indoor air samples were collected at 19 school in three different areas of southern Korea region from September to October 2009. The concentrations of PM-10 and formaldehyde in all sampling sites were below indoor air quality guideline of the Ministry of Education, Science and Technology. The CO₂ level and TBC (total bacteria count) were higher than the guideline for 4 sites and 12 sites, respectively. The concentration of TVOC for 23 sites exceeded the guideline. Also, TVOC level of metropolitan sampling sites were somewhat higher than small and medium-size city sampling sites. The concentration of indoor air pollutants affected by various conditions such as season, region, and indoor/outdoor environment. This study result shows that concentration of several pollutants such as CO₂, TBC, and TVOC were higher than the guideline for some sampling sites. Therefore, it is necessary to manage indoor air quality and establish effective emission reduction strategies regard for characteristics of each 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.

Studies on the indoor air quality inside newly producted vehicle have made mainly mention of the concentrations for indoor air pollutants or of subjective symptoms, such as irritated eyes and nose, headache and dizziness. That is, there has been no report about how poor indoor air quality inside newly producted vehicle affects vehicle drivers. We measured the indoor air pollutants inside newly producted vehicle and evaluated the neurobehavioral performance of drivers, using a computerized neurobehavioral test (color word vigilance), between a newly producted and a 11-year-old vehicle. Inside the newly producted vehicle, the formaldehyde concentration with closed window was 19.1㎍/m³. The concentration of VOCs with closed window was 3.9㎍/m³ for benzene, 316.7㎍/m³ for toluene, 20.5㎍/m³ for ethylbenzene, 47.7㎍/m³ for m,p-xylene, 15.1㎍/m³ for o-xylene, and 15.3㎍/m³ for styrene. The neurobehavioral performance of drivers inside newly producted vehicle with the computerized neurobehavioral test was 11.05% lower than that for those inside 11-year-old control vehicle. These results suggest that the poor indoor air quality inside newly producted vehicle affects the neurobehavioral performance of driver and a proper evaluation of the indoor air quality inside newly producted vehicle is required into the health effects of pollutants with objective tool, in addition to the level of pollution.

The purpose of this study are to examin the level of temperature, relative humidity and pollutants at stock rooms in National Archives and to provide fundamental data in order to protect damage of archives. The survey of indoor air quality(IAQ) in stock rooms was performed in Busan National Archives in August and December 2007, and collected basic data, on level of them at stock rooms in National Archives that were published. The temperature and relative humidity in stock rooms were within the terms of national law of the public archives administration. The concentration of PM10 in stock rooms in National Archives exceeded 50 ㎍/m³, which is the guideline of national law for the public archives administration. The concentration of CO, SO₂, NO₂, O₃ and Formaldehyde in stock rooms did not exceeded the guideline of national law. The concentration of total volatile organic compounds was shown to exceed the guideline of natioanl law. Therefore, we suggest that a national plan for the management of IAQ at stock rooms in National Archives should be established through a long-term, continuous investigation

In this work, pellet type sorbents were prepared to control the low level indoor carbon dioxide with various physical compositions. In order to enhance the adsorption capacity, a few additives including alkali hydroxides were added to a commercial zeolitic sorbent by impregnation of alkali cation - Ca²⁺ through physical mixing and ion exchange. It was found that the binding materials such as dextrin or bentonite facilitating to form the granular sorbents would assist the adsorption capacity of sorbents. The ion exchange was more efficient for impregnation of alkalies, which showed better adsorption of gaseous CO₂.

Secondhand smoke (SHS) is one of major public health threats in morbidity and mortality. Several national and regional comprehensive smoke-free regulations have been implemented to prevent public health exposure, but not in Korea. The purpose of this manuscript was to review impacts of the national or regional smoke-free legislations on indoor air quality, health effects and smoking behaviors. Indoor air quality has been improved significantly after smoke free policy. Such improvement was measured by fine particulates and urinary cotinine. Respiratory and cardiovascular health effects were significantly improved after smoke free policy. This is an indirect evidence of association between secondhand smoke exposure and the health effects. Respiratory symptoms were improved as short as one month after smoke free policy. Smoke free policy was also associated with improved perception of danger of secondhand smoke. Reduction of smoking prevalence was also unexpected benefit of smoke free policy. As reviewed in this paper, smoke free policy can be beneficial to indoor air quality, health effects and smoking behaviors. Since Korea does not have comprehensive smoke free policy yet, it is strongly recommended to implement national comprehensive smoke free policy.

Recently Korean government introduced and strengthened the environmental polices to manage and enhance indoor air quality as a major assignment. As a result,“Indoor Air Quality Management Act”has been activated since May 2004. However, among many multi-usage facilities, the school environment has been excluded from such regulations. Thus, the purpose of this study is to survey indoor aerosol and CO2 concentrations in a university library which is one of major school facilities. Concentrations of PM10, PM2.5, and PM1 were intensively measured every 5 minute interval by means of a dust monitor with light-scattering principle. The mini-volume air samplers were used further to analyze inorganic elemental compositions of PM10 and to inter-compare with the dust monitor. Carbon dioxide was simultaneously monitored by a multi-gas monitor equipped with a non-dispersive infrared system. PM10 concentrations did not exceed the indoor air quality standard(150㎍/㎥) for all the sampling places. However, quick and steep increases of aerosol concentration were observed during the Asian Dust storm period. In addition, the concentration of PM10(74.1㎍/㎥) in the main university office was the highest among the entire sampling places. Although there was no specific pollution source in the library, the levels of aerosol and CO2 increased quickly due to various outdoor sources and human activities. The average CO2 concentration measured in three reading rooms, where ventilation was not fully operated, exceeded the indoor air quality standard of 1,000 ppm. Based on these case studies, effective management and reduction plans for indoor aerosol and CO2 were suggested for the large scale public buildings including university libraries.

This study was surveyed to evaluate and recognize the distribution characteristics of indoor air pollutants(IAPs) such as the total volatile organic compounds(VOCs), formaldehyde(HCHO), PM10, carbon dioxide(CO2), nitrogen dioxide(NO2), ozone(O3) and radon in 10 elementary schools located in urban, rural, and industrial complex area from November 2005 to February 2006. The average concentration of IAPs were 117.9㎍/㎥ as in PM10, 1,971ppm as in CO2, 486.6㎍/㎥ as in TVOC. These chemical's concentration was exceeded the indoor air standards of the Department of Education in Korea. The indoor concentrations of ozone and toluene was lower than that of outdoor and other pollutants showed the opposite tendency. In schools located industrial complex area, the outdoor concentration of TVOC was higher than that of urban and rural area. Based on the results above, PM10, CO2, TVOC have to be in the order of priority to improve the indoor environment in school. Also it should be performed in the detailed survey considered by the seasonal variation because this study showed cross-sectional results.

Young children health problem were reported in a Korean daycare centers and supposedly attributed to the presence of air pollutants. This study attempted to characteristics of carbonyl compounds exposure of young children at the indoor spaces. The characteristics associated with the major indoor pollutants exposure included seasonal variation, and room location inside a daycare centers. As the results of investigation for daycare centers, the mean concentrations of formaldehyde, acetone, and acetaldehyde in daycare centers were 38.3㎍/m3, 33.9㎍/m3, 13.6㎍/m3, respectively. The indoor space carbonyl compounds concentrations were both higher for the summer than for the other seasons. The temperature and relative humidity measured along with the volatile organics measurements temperature and relative humidity increase volatile organics levels. This last suggestion is further supported by the correlations of the carbonyl compounds measured for daycare centers. Significant correlations between carbonyl compounds were exhibited for both the temperature and humidity, with at least p<0.05. The concentrations of formaldehyde in classroom were higher than lobby or dining room. Therefore, controlling indoor air pollutants exposure in daycare center should be given a high priority so as to minimize the potential sources of air pollutants in indoor space.

The objective of this study is to offer basic scientific data to support policy decision-making for the improved control of suspended microorganism and to provide baseline data in order to improve the studies of bioaerosol in Korea. Therefore, this study collected and re-analyzed articles on suspended microorganism in various indoor environments and atmospheric environment in Korea that were published in environmental journals since 1980. The survey on the bioaerosol concentration in hospital among the public facilities have been performed abundantly. Also, the survey on the distribution of microorganism during yellow sand, pollen and fungus in atmosphere have been performed mostly. The impactional sampling method that is the sampling method of suspended microorganism have been used mostly in the survey on bioaerosol in Korea. Among the various indoor environments, the pooled average total bacteria concentration of 222.75 CFU/㎥ (95% CI：210.29 ∼ 245.22 CFU/㎥) was found in hospitals. It were lower than the guideline concentration (800 CFU/㎥) recommended by the Korean Ministry of Environment. And the pooled average concentration of bacteria and fungi in houses was 148.06 CFU/㎥(95% CI : 20.39 ∼ 275.74 CFU/㎥) and 22.66 CFU/㎥(95% C I：0 ∼ 49.73 CFU/㎥) respectively. Staphylococcus spp., Micrococcus spp., Enterococcus., Corynebacterium., Escherichia spp., and Pseudormonas spp. for bacteria and Penicillium spp., and Aspergillus spp. for fungi were showed in various indoor environments.

This study was to investigate distribution characteristics for air pollutants and to assess probability of health effect for children in kindergartens from August, 2006 to January, 2007. The mean concentrations for standards of maintenance in kindergartens were 91.5 ㎍/㎥ for PM10, 1,185 ppm for CO2, 69.3㎍/㎥ for formaldehyde, 174 CFU/㎥ for TBC and 0.41 ppm for CO, respectively. For NO2, Rn, TVOC, and O3, the mean concentrations in kindergartens were 29.40 ppb, 1.51 pCi/ℓ, 257.3 ㎍/㎥, and 3.74 ppb, respectively. The I/O ratio of every air pollutants exceeded "1" except for O3. In results of calculated safety factor to assess probability of health effect for children by air pollutants in kindergartens, safety factor for CO2 was 1.2 for fixed point. It means that children have probability of health effect caused by CO2. In cases of Monte-Carlo analysis, safety factor for PM10 was 1.0 and safety factor for CO2 was 1.2.

This study was undertaken to investigate the distribution characteristics of the hazardous agents in indoor environment in 7 vessels in Incheon harbor from July to August, 2004. The measured parameters include several indoor air pollutants (PM10, CO2, HCHO, and TVOCs) and physical parameters (noise, vibration, temperature, and humidity). The levels of pollutants and hazardous components in vessels were compared with standards and guidelines of indoor air quality on the Ministry of Environment and the Ministry of Labor in Korea. The major results obtained from this study were as followed : The PM10 and CO2 levels in every vessel did not exceed the indoor air standard of 150 ㎍/㎥ and 1000 ppm, respectively. The level of PM10 showed a decreasing tendency as the weight of vessels is increased. The airbornce concentration of HCHO was the highest one by exceeding its standard in a 500 ton vessel. The noise level in engine room exceeded the workplace standard (90 dB(A)) recording above 100 dB(A). The TVOCs level in every engine room was more than its standard (500㎍/㎥). Based on our preliminary study of indoor air pollutants in vessels, it is suggested that long and middle term plan for the management of IAQ should be established through future investigation of vessels.

This study was performed to investigate the characteristics of indoor air quality (IAQ) in elementary and middle schools in Gyeongbuk area from July to November 2006 . The measurements of indoor air pollutants were made to cover such components as PM-10, CO2, CO, NO2, O3, HCHO, TVOC, TBC, and Radon from school classrooms. The results of this study can be summarized as follows: all of them were less than IAQ standards of Korea. The mean concentration were measured by 43.0 ㎍/㎥ (PM-10), 745 ppm (CO2), 56.1 ㎍/㎥ (HCHO), 350 CFU/㎥ (TBC), 0.026 ppm (O3), 0.6 ppm (CO), and 59.2 ㎍/㎥ (TVOC). Radon was not detected in all surveyed classrooms. The I/O ratio of PM-10 was 0.8∼1.4, while that for HCHO was 5.7∼9.0. Therefore, it was concluded that the indoor pollution of formaldehyde was very serious in classroom.

This study was performed to investigate indoor air quality and to characterize the concentration of particulate matters followed by human activities in preschool classrooms. Concentrations of PM10, PM2.5, and PM1 were measured every 5-minute intervals by means of a dust monitor adopting the principle of light scattering. Two mini-volume air samplers were used further to measure the I/O concentration ratio of PM10 and to calibrate the dust monitor since the photometric method often exaggerates the mass of fine particles. The calibration factor in the study environment was determined as 0.64. In the preschool classrooms, the ranges of average indoor PM10, PM2.5, and PM1 concentrations were 51.5~117.6, 21.5~98.4, and 16.2~84.5 ㎍/ ㎥, respectively, while that of I/O concentration ratio was 0.8~1.3. Based on correlation analysis among various environmental parameters, PM1 was slightly correlated with humidity (r=0.416, p<0.01). However, outdoor PM10 was strongly related with indoor PM2.5 (r=0.95, p<0.01), with PM1 (r=0.94, p<0.01), and with PM10 (r=0.84, p<0.01). The trend of PM2.5 and PM1 concentrations appeared to be very similar unlike the case of PM10. Since the elevated coarse particle concentration (2.5㎛<dp<10㎛) and the average PM2.5/PM10 ratio were highly dependent on classroom activities, the parameter of PM2.5/PM10 ratio was intensively studied with 7 different indoor activities in the preschool classrooms.

Vehicle drivers are subject to be exposed to high concentrations of airborne pollutants emitted from vehicles on roads. To investigate the indoor air quality of vehicles on roads, black carbon (BC) was measured inside a passenger car commuting between the residential area in southern Seoul and the Korea Institute of Science and Technology (KIST) in northern Seoul using a portable aethalometer. When the vehicular windows were closed, the ventilation mode was set to fresh air mode (or circulation mode) for a total of thirteen runs made during May 2005. When the windows were open, the analysis was made with the system turned off (for twelve runs in October 2005). The BC concentration depended on such parameters as spatial location, time of day, and ventilation mode. The average BC concentration measured on non-express ways was higher than those measured on express ways, inside KIST, and nearby the residential area for most runs. On circulation mode, the average BC concentration was 5.9±1.7 ㎍/㎥ in the afternoon or evening, which was similar to a 24-hr average BC concentration for ambient air at 200 m apart from a road in Seoul. In the case of fresh air mode, the average BC concentrations measured in the morning rush hour, in the afternoon or evening, and after midnight were 22.8±3.4, 15.9±7.7, 3.7 ㎍/㎥, respectively. The average BC concentrations measured with the vehicular window open were 31.9±9.2, 19.4±5.9 ㎍/㎥, respectively in the morning rush hour and in the afternoon or evening. These measured values were higher than those measured with the windows closed. The average BC concentrations inside a passenger car with a fresh mode operation or open-window driving were significantly higher than a 24-hr average BC concentration measured at 200 m apart from a road in Seoul.