This study was carried out to investigate the effect of malodor and VOCs reduction that could be achieved through the installation of a vapor recovery system (VRS) in a gas station. It was revealed that the reduction efficiencies of malodor by running VRS were about 93% around the oil feeder, 32% in the office and 45% in the site boundary. Specifically, it was remarkable that reduction efficiencies of BTEX over 90% were recorded through VRS operation. In addition, the results of continuous monitoring of THC around the oil feeder device provided good evidence of the inhibition of oil mist diffusion after running VRS.

The study measured the volatile organic compounds consistency of the child tympanitis patient family. Benzene, the result which analyzes toluene, ethylbenzene, xylene and TVOC consistency, case of personal exposure they were 0.518 μg/m3, 0.909 μg/m3, 1.299 μg/m3, 0.960 μg/m3 and 273.718 μg/m3 respectively, case it appeared with benzene the interior 0.539 μg/m3 and toluene 1.433 μg/m3 and ethylbenzene 1.253 μg/m3 and xylene 1.899 μg/m3 and TVOC 262.132 μg/m3. The consistency of the outdoor benzene, toluene, ethylbenzene, xylene and TVOC appeared respectively with 0.512 μg/m3, 0.474 μg/m3, 1.177 μg/m3, 0.862 μg/m3 and 22.306 μg/m3. Personal exposure, the residential interior, interrelationship analytical result Benzene of outdoor consistency and Ethyl benzene, Xylene and TVOC personal exposures with the interior and outdoor consistency showed the interrelationship which considers(p < 0.01). VOCs consistency which it follows in residential type the detached home > the multi generation house > the consistency price came out with the apartment order, VOCs consistency which it follows construction year possibility the year valence which is built 4 years at once rises the consistency appeared more highly the case where the case is above 4 years than.

This research determined the threshold value of 10 specified offensive odor substances based on the 3 point comparison sensory method. The panelist's thresholds were calculated by taking the arithmetic, geometric mean, and 50th percentile. Three methods of calculating the odor thresholds from the same data are compared. For 10 odor substances, the panelist's thresholds revealed a logarithmically normal distribution. The 50th percentile was the best method among the three methods of calculating the odor threshold from the 270 thresholds of 18 panels. As a result, the threshold values of individual odor substances, including i-valeric acid, n-valeric acid, n-butyric acid, and butyl acetate ranged between 0.0001~0.006 ppm, while the values of methyl ethyl ketone and toluene were relatively higher than that of other substances at 0.7107 ppm and 1.2139 ppm, respectively. The threshold values of the 10 specified odor substances were compared in Korea and overseas, which showed that the characteristics of sensory response varied by substance and nation.

This study attempted to decompose typical odorous VOCs including toluene, isopropyl alcohol, benzene and acetone using a dielectric barrier discharge plasma in a pilot experiment scale up to 60 m3/min. It utilized oxygen ions(205,000 ions/cm3) and various radicals formed by a plasma generator. Although ozone as a byproduct( approximately 300 ppb) contributes to destroying organic compounds in their gas phase, the residual release could be captured by post manganese filters showing a maximum 30% removal. The present process was more effective for acetone, which is composed of relatively simple molecules, with a 56% decomposition rate. Whilst toluene, benzene and isopropyl alcohol were shown to have of rates of 19%, 37% and 36% respectively.

The objectives of this study were to characterize the factors affecting exposure to the VOCs and NO2 in the vicinity of Gwangyang industrial complex. The VOCs and NO2 levels were measured for residents of an exposure group (industrial area within 5 km) and a control group (15 km farther), respectively using the VOCs and NO2 filter badge as a passive sampler from August to September 2006. The means of indoor, outdoor, workplace and personal exposure levels of benzene were 1.10 ppb, 0.94 ppb, 1.85 ppb and 2.35 ppb respectively in the exposure group. The means regarding toluene for the exposure group were 9.29 ppb indoor, 8.09 ppb outdoor, 14.5 ppb workplace, 14.2 ppb personal exposure. The means regarding ethylbenzene were 4.96 ppb(indoor), 4.45 ppb(outdoor), 6.84 ppb (workplace), 6.10 ppb(personal exposure), and the means regarding xylene were 0.10 ppb(indoor, outdoor), 0.18 ppb(workplace) 0.17 ppb(personal exposure). The means for the indoor, outdoor, workplace and personal exposure level of NO2 were 18.40 ppb, 18.51 ppb, 18.59 ppb, 18.80 ppb respectively in the exposure group. Correlations between personal exposures and workplace concentrations of individual VOCs and NO2 exposures, and each of the microenvironment was statistically significant.

Indoor pollutants seem to have a negative affect on people from vulnerable households who are considered to be weak by the department of environmental health, such as the elderly, infants, children, patients, and pregnant women. In this study, the concentrations of pollutants were measured, especially those pollutants that endanger vulnerable households such as PM10, HCHO, TVOCs, TBC and fungi. The measurements were taken from September to October of 2013 in the Chungnam area. The results were as follows: PM10 33.2 μg/m3, HCHO 20.35 μg/m3, VOCs 132.30 μg/m3, TBC 562.71 CFU/m3 and fungi 362.04 CFU/m3. In the case of TBC and fungi, there were excessive concentrations at 30.9% and 49.3% compared to the standards set by WHO. In the case of fungi, buildings built before the 1980s showed a concentration of 446.23 CFU/m3, those built in the 1980s and 1990s had a concentration of 320.21 CFU/m3 and those built in the 2000s had a concentration of 313.43 CFU/ m3 indicating that fungi concentration was higher when the building was older. The correlation analysis between indoor air pollutants and factors affecting indoor concentrations indicate that HCHO (r = 0.423), TVOCs (r = 0.329), and humidity (r = 0.359) showed a significant difference (p < 0.01). The current study focused on vulnerable households that were unable to protect themselves from indoor pollutants and where poor living circumstances prevailed such as households that do not receive much sunlight; thus, more attention and focus needs to be given to these particular households

In this study, the characteristic of the facilities and indoor environment for the senior citizens nursing facilities of Kyeonggki and Seoul-total 30 facilities;10 facilities in Seoul and 20 facilities in Kyeonggki from January to December in 2007. In the result of surveying indoor and outdoor pollution degree of 30 senior citizens nursing facilities, the average geometric concentration of indoor and outdoor TVOCs were 264.11 ㎍/㎥ and 162.63 ㎍/㎥, respectively. On the other hand, the average geometric concentration of indoor and outdoor HCHO were 22.76 ㎍/㎥ and 9.55 ㎍/㎥, respectively. The concentration ratio of indoor and outdoor air pollutants were 1.21, 1.23, 1.62 and 2.38 for benzene, toluene, TVOCs and HCHO, respectively. The concentrations of toluene, TVOCs and HCHO were 31.40 ㎍/㎥, 274.30 ㎍/㎥ and 24.17 ㎍/㎥ in the building constructed after 2000. On the other hand, The concentrations of toluene, TVOCs and HCHO were 27.99 ㎍/㎥, 248.54 ㎍/㎥ and 20.48 ㎍/㎥ in the building constructed before 2000. As the constructed year was not late, low concentration was indicated. In the facilities using carpet or not, the concentration of toluene, TVOCs and HCHO were 50.50 ㎍/㎥, 342.73 ㎍/㎥ and 32.94 ㎍/㎥, respectively, in the facilities using carpet. On the other hand, the concentration of toluene, TVOCs and HCHO were 29.35 ㎍/㎥, 261.41 ㎍/㎥ and 22.40 ㎍/㎥, respectively, in the facilities using no carpet. The concentrations were presented higher in the facilities where carpet exits.

An elementary school is an important public place for children and it is where they spend most of their days. Ten elementary schools of environmental pollutants were measured in the classroom, playground and school zones (June 19 ~ Nov 1, 2012). Dust measurements of some schools were more indoor air. Measurements of black carbon concentrations were higher overall school zones. Also, in the case of formaldehyde, benzene and some environmental standards were exceeded. In the case of outdoor pollutants not statistically significant, but in some cars and vans that were correlated with pollutants. Thus, strategies and actions are necessary that will protect the health of children in schools from environmental pollutants.

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.

This study was carried out to provide the stable and homogeneous sample for the proficiency test which was applied for the olfactory dilution method of the offensive odor. For this purpose, the relationship between VOCs concentration and air dilution test results were analysed. As the results, the mixture of 7.1 ppm of toluene and m-xylene were suitable as a low level of PTM(proficiency test material) for air dilution olfactory method. In addition, time stability and homogeneity between samples were investigated through the time of 6 hr ~ 48 hr. As the results, the stability of sample concentration with GC analysis was shown as 5.1% RSD for toluene and 6.8 %RSD for xylene, respectively. The stability of sample was 5.4 %RSD in terms of air dilution olfactory method.

다성분계 휘발성 유기화합물(VOCs; Volatile Organic Compounds)의 분리를 위하여 상전이법을 이용하여 방사 한 poly (ether imide) (PEI) 중공사 지지체에 poly (dimethylsiloxane) (PDMS)를 코팅하여 중공사 복합막을 제조하였다. VOCs 회수용 중공사막으로서 적합성을 알아보기 위해서 중공사막의 모폴로지, 질소 및 산소 기체 투과도를 측정하고, 벤젠, 톨루엔 그리고 자일렌에 대한 내구성을 조사하였다. 다성분계 휘발성 유기화합물의 효과적인 분리성능을 조사하기 위하여 Stage-cut과 feed 농도에 따른 다성분계 VOCs 투과 성능 변화를 관찰하였다. PEI 지지체 중공사막에 PDMS를 코팅시킴 에 따라 산소와 질소 투과도는 각각 45,000 GPU와 49,450 GPU에서 63 GPU와 30 GPU로 감소하는 것을 확인하였다. VOCs 투과농도는 Stage-cut이 감소함에 따라 증가하나, 회수율은 감소하였다. 반면에 공급농도 증가에 따라 투과농도는 비례적으로 증가하였지만, 농축비나 회수율은 큰 변화가 없었다.

도장공정에서 발생되는 휘발성 유기화합물의 회수를 위하여 중공사 분리막 모듈을 이용한 공정을 준비하여, 공급 압력과 시간변화에 따른 휘발성 유기화합물의 회수에 대한 특성평가를 실시하였다. 중공사 분리막 모듈을 도장공정에 직접 적용한 결과, 투과된 휘발성 유기화합물의 농도는 투과시간과 압력의 증가됨에 따라 증가되었으며, 단일공정보다 다단공정이 더 우수한 분리성능을 나타내는 것을 확인하였다.

This study was performed to evaluate the type and concentration of TVOC and formaldehyde emitted from asbestos stabilizers, because the stabilizers can be applied on the surface of asbestos contained building materials(ACBM). The emission test of three organic and synthetic resins(OSBS) and five inorganic based stabilizers(IBS) were tested for 7 days. The amount of emission and concentrations of TVOC were measured using GC/FID and GC/MS. In case of formaldehyde, quantitative analysis was carried out using HPLC. The average concentrations of TVOC and formaldehyde of 8 stabilizers were 1.173 mg/m²․h and 0.007 mg/m²․h, respectively. The maximum TVOC concentration among five OSBS was 5.698 mg/m²․h and exceeded the TVOC emission standard(4.0 mg/m²․h) for general building materials. According to the this study results, the applied stabilizer can be role one of pollutant sources like paints, floor tile etc. The emission test has to be tested one of stabilizers efficiency to manage the indoor air quality of building.

Information on time spent in microenvironments has a critical role in individuals’ exposure assessment. Time-activity studies have become an integral part of comprehensive exposure assessment and personal exposure modeling. The aims of this study were to estimate the exposure level of NO₂, PM₁₀ and VOCs, and to compare the estimated exposure by using time-activity pattern and indoor air concentration. This study was performed upon 28 university students living in Daegu. We measured air pollutants of NO₂, PM₁₀ and VOCs at houses where the university students spent most their times. In this study, according to the summer and winter, time-activity patterns of university students were different. The 28 university students average spending times in house indoors and other indoors time were 11.52±2.14 and 7.63±2.65 hours in summer, and 14.78±3.30 and 6.59±3.03 hours in winter, respectively. The university students personal exposure NO₂ concentrations were average 21.62±5.88 ppb and I/O ratio was 0.89±0.27. Personal average exposure of PM₁₀ concentration was between house indoors and outdoors concentrations which indoor house concentration was 37.68±7.57 μg/m³ and outdoor house concentration was 43.85±9.80 μg/m³ with 0.88±0.17 of I/O ratio. Personal exposure to benzene and the average concentration of benzene did not exceed in atmosphere environmental standard (annual 1.5 ppb) and the outdoor houses concentration was much higher than indoor houses.

This study was aimed to elucidate the cause of odor in a park, which was used for the landfill site about 20 years ago. For this purpose, VOCs concentration was measured using passive sampler at 10 sampling sites around a park for two times (spring and summer). The VOCs concentration measured in summer showed very low concentration and the relative VOCs ratio also showed no special patterns relating with other studies, which was caused to heavy rainfall during the sampling period. However, the relative ratio of toluene concentration of two sampling sites in spring appeared very high relating with other studies. It was thought that the high VOCs concentration in this park was caused not by landfill but by a neighboring painting materials company.

VOCs의 분리 및 회수를 위해 PEI 고분자를 이용하여 상분리법으로 중공사 지지체 분리막을 제조하였고 PDMS 고분자를 코팅하여 PEI-PDMS 중공사 복합막을 제조하였다. 제조된 기체 분리막의 특성을 알아보기 위하여 산소와 질소를 이용하여 순수 기체 투과도를 측정하였으며, xylene, ethyl benzene, toluene, cyclohexane을 이용하여 stage cut과 feed 농도 변화에 따른 투과성능을 측정하였다. 또한 VOCs에 대한 내용매성을 알아보기 위하여 DMA을 이용하여 용매 함침 시간에 따른 stress-strain 특성을 알아보았다. 산소와 질소의 순수 투과도는 각각 63 GPU와 30 GPU를 나타내었고, stage cut이 증가할수록 permeate VOCs 농도는 감소하는 경향을 나타내었다. Recovery efficiency의 경우 permeate 농도와는 반대로 state cut이 증가할수록 증가하는 경향을 나타내었다. DMA 인장 테스트 결과 stress는 11.93 MPa, strain은 13.52%로 측정되었다.

There has been a growing concern about the emissions of formaldehyde and VOCs from automotive interior materials which could have an important impact on the in-vehicle air quality(IVAQ) of automotive vehicles. Many leading automobile manufacturers have now introduced their own specification standards for testing and limiting emissions from products produced by their suppliers. In addition, ISO (International Standard Organization) has been established ISO 12219-1, 2, 3, 4, 5 to determine the emissions of volatile organic compounds from automotive vehicle. The objective of this paper is to compare the area specific emission rates determined from surface emissions testing using the microchamber(MC) in comparison with a 1 m³ emission test chamber(ETC) operated in accordance with ISO 12219-3, ISO 12219-4. Measured emission concentrations in absolute terms were different between Microchamber and 1 m³ chamber. However, qualitative comparison of the chromatograms shows that the Microchamber is able to perform a screening test

A bake-out process using auto switchgear was carried out to evaluate the reduction effect of the concentration of volatile organic compounds (VOCs) and formaldehyde in newly-built apartments for seven days. The reduction rate of VOCs was observed as followings: 19%, 38%, 89%, 90%, and 96% for benzene, toluene, ethylbenzene, xylene, and styrene, respectively, which satisfies at the indoor air quality standards of newly-built apartment houses in Korea. The reduction rate of formaldehyde was 75%. Those results proved that the bake-out process using auto switchgear was effective for reducing indoor air pollutants.

This study was to assess the lifetime cancer and non-cancer risk on exposure to volatile organic compounds This study was assessed the lifetime cancer and non-cancer risk of volatile organic compounds (VOCs) exposure in young children at elementary-schools and academies in Korea. The samples were collected at children's facilities (50 elementary-schools and 42 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods, and analyzed by GC-MSD. We estimated the lifetime excess cancer risks (ECRs) of benzene and the hazard quotients (HQs) of non-carcinogens toluene, ethylbenzene, xylene and styrene. In addition, for carcinogens, the excess cancer risk (ECR) was calculated by considering the process of deciding cancer potency factor (CPF) and age dependent adjust Factor (ADAF) from the data in adults. The average ECRs of benzene for young children were 1×10^-7~1×10^-9 level in all facilities. HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities.

This paper presented experimental results for circulation type UV-TiO₂ photocatalytic oxidation process. We have developed UV-TiO₂ photocatalytic oxidation process with activated carbon to control odor and VOCs in indoor and industrial applications. In this study, common indoor air pollutants, namely ammonia, formaldehyde, hydrogen disulfide, toluene were selected to investigate their efficiencies for UV-TiO₂ photocatalytic oxidation. In high concentration test, the decomposition efficiency was high in order as ammonia, toluene, formaldehyde, hydrogen disulfide. Three type of individual processes are tested for ability to increase decomposition efficiency. UV-TiO₂ photocatalytic oxidation combined process with activated carbon was excellent among the three type processes without reference to gas species. It was considered that this circulation type process will overcome short retention time for treatment for UV-TiO₂ photocatalytic oxidation. It will promise that this circulation type UV-TiO₂ photocatalytic oxidation combined process can apply indoor and industrial applications to remove odor and VOCs quickly.