• 한국대기환경학회지
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• 제30권5호
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• pp.477-491
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• 2014

This study was carried out to evaluate the concentration variations of volatile organic compounds (VOCs) in the office environments located in a large urban area with respect to seasonality, smoking status, types of ventilation and heating. Indoor air sampling was undertaken in 37 and 30 offices in Daegu city during summer and winter, respectively. The VOC samples were collected using adsorbent tubes, and were determined by thermal desorption coupled with GC/MS analysis. The analytical method was validated for repeatability, method detection limits (MDL), and duplication precision. A total of 34 VOCs of environmental concern were determined, including 15 aromatics and 19 halogenated hydrocarbons. Average concentrations of BTEX appeared to 1.91 ppb, 22.98 ppb, 3.44 ppb, and 3.70 ppb, respectively. These values were relatively higher levels than those measured at homes and outdoor roadsides reported by other researches. In general, the concentrations of VOCs were higher in winter than summer, in smoking offices than non-smoking offices, in forced ventilation type than natural ventilation type, and in combustion heating than non-combustion heating offices. However, such differences were not always significant at a level of 0.05 by statistical tests (t-test and/or Mann-Whitney test) with some exceptions for BTEX and styrene. This study demonstrated that smoking status, ventilation type and presence of combustion sources indoors could be important factors on the elevated concentrations of some VOCs in the office environment.

• 한국환경과학회지
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• 제1권1호
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• pp.41-46
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• 1992

주거지역에서 대기오염물 시료채취에 대한 장기간 연구를 수행하기 위해서 휘발성 유기 화합물 분석에 적합한 24시간동안의 종합적인 공기시료를 채취하기 위해 공기시료 채취기가 제작되었다. 이 시료 채취기는 시료채취시 요구되는 모든 특성을 포함할 뿐만 아니라, 일반가정에 근접해서 설치되어야하므로 심미적 특성도 포함한다. 이 공기시료 채취기는 흡착제(티넥스)로 채워진 5/8인치 외경의 스테인레스 스틸 트랩 네개를 수용할수 있고, 분당 5-50 밀리리터의 범위에서 네 종류의 공기유속을 이용할수 있게 고안 되었다. 금속필도(10마이크로미터)가 트랩 어댑터의 입구에 직접 부착되었다. 부가적인 특성은 다음과 같다. : 1) 유기물질에 불활성인 재료로 제작 되었고, 2) 날씨에 영향을 받지 않고, 3) 전지를 이용하고, 4) 사람의 호흡영역에서 공기 시료를 채취하고, 그리고 5) 방음제로 싸여진 작은 펌프를 이용하여 조용하게 작동된다. 펌프/전지 장치는 시료채취기의 본체로부터 분리 되었다. 이 장치로 부터 야기되는 소음수준은 주거지역의 허용기준치(뉴저지주 환경보호국 기준)보다 낮았다. 이 공기시료 채취기는 일상 주거지역과 단층의 한 국민학교 옥상에서 성공적으로 작동되었다.

• 한국분무공학회지
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• 제20권2호
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• pp.121-129
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• 2015

This study was designed to investigate the emission characteristics of unregulated pollutants (Aldehyde, VOCs, PAHs) as well as regulated pollutants (CO, HC, NOx and PM) from diesel medium-duty trucks. The emission characteristics of unregulated and regulated pollutants were assessed based on regulation standards (EURO 4 and EURO 5) and intake weight (2.5 ton and 5 ton). The results show that unregulated and regulated pollutants remained almost unchanged at higher speeds but decreased at below 23.5 km/h. Reduction in unregulated and regulated pollutants was noticeable in vehicles of recent regulation standards and light intake weight. The analysis of aldehyde using UPLC showed that formaldehyde and acetaldehyde of aldehyde were most dominant. The GC/MS analysis showed that benzene, toluene, ethylbenzene and xylene of VOCs was over 80% followed by toluene, xylene, ethylbenzene and benzene. In addition, the analysis of PAHs using GC/TOF-MS indicated that bi- and tricyclic aromatic ring of aromatic compounds was 73% and 53% at 2.5 ton and 5 ton vehicles, respectively. The results of this study will be contributed to establish HAPs inventory.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.183-191
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• 2008

Volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. And VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Benzene is the most widely used prototypical VOC and the toxic mechanisms of them are still unclear. The multi-step process of toxic mechanism can be more fully understood by characterizing gene expression changes induced in cells by toxicants. In this study, DNA microarray was used to monitor the expression levels of genes in HepG2 cells and HL-60 cells exposed to the benzene on IC20 and IC50 dose respectively. In the clustering analysis of gene expression profiles, although clusters of HepG2 and HL-60 cells by benzene were divided differently, expression pattern of many genes observed similarly. We identified 916 up-regulated genes and 1,144 down-regulated genes in HepG2 cells and also 1,002 up-regulated genes and 919 down-regulated genes in HL-60 cells. The gene ontology analysis on genes expressed by benzene in HepG2 and HL-60 cells, respectively, was performed. Thus, we found some principal pathways, such as, focal adhesion, gap junction and signaling pathway in HepG2 cells and toll-like receptor signaling pathway, MAPK signaling pathway, p53 signaling pathway and neuroactive ligand-receptor interaction in HL-60 cells. And we also found 16 up-regulated and 14 down-regulated commonly expressed total 30 genes that belong in the same biological process like inflammatory response, cell cycle arrest, cell migration, transmission of nerve impulse and cell motility in two cell lines. In conclusion, we suggest that this study is meaningful because these genes regarded as strong potential biomarkers of benzene independent of cell type.

• 한국대기환경학회지
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• 제15권1호
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• pp.63-69
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• 1999

To offer a general guideline for the quantitative analysis of airborne pollutants, we designed and conducted a comprehensive QA/QC test using two different strategic approaches, namely (1) field-based comparative measurement and (2) laboratory-based comparative analysis. The former task was performed to make meaningful comparison of combined errors occurring from both sampling and analytical techniques in the measurements of such components as: (1) criteria pollutants, (2) volatile organic compounds (VOCs), and (3) particulate matters with the associated metals and ions. The latter task was also conducted to compare various types of bias arising mainly from the laboratory analytical procedures of (1) gaseous standards of VOCs and (2) of aqueous standards of metals and ions. The concentration data derived from each of these two different types of major tasks were evaluated per chemical species categorized as above. While the very details of these studies are to be reported on an individual basis according to the above classification of the project, this paper is presented to provide an overview of the whole project - its aim and direction.

• 한국환경보건학회지
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• 제33권4호
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• pp.242-249
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• 2007

Indoor air quality has become a topic of interest and concern. Especially changes in construction design and the increased use of synthetic products may result in an increasing of complaints and health effects about the quality of indoor air at home. In this study, nitrogen dioxide($NO_2$) and volatile organic compounds(VOCs) within new and established apartments on the basis of 4 years of building year were measured every 3 days consecutively during 60 days. We selected each 10 house in Seoul, Asan and Daegu, respectively, and produced risk numbers for hazard quotients, and predicted increases in incidence of cancer. The calculations were made for the adult with default exposure values and also made for a worst case scenario using Monte-Carlo simulation as describing the reasonable exposure(RME). Mean of Monte carlo analysis by benzene, in the construction under 4 years (male: $9.2{\times}10^{-5}$, female: $1.0{\times}10^{-4}$) and over 4 years (male: $6.8{\times}10^{-5}$, female: $8.3{\times}10^{-5}$) exceeded $10^{-6}$ of permitted standards in US EPA, RME of Monte carlo analysis. In construction under 4 yews (male: $9.9{\times}10^{-3}$, female: $9.6{\times}10^{-3}$) and over 4 years (male: $9.8{\times}10^{-3}$, female: $7.8{\times}10^{-3}$) exceeded $10^{-4}$ of maximum permitted standards in US EPA. The hazard index of non-carcinogenic pollutants by nitrogen dioxide, toluene, m,p-xylene and o-xylene, both male and female in apartment constructed under 4 yews and over 4 years was found less than the permitted standards of hazardous health effects in CTE. Significant cancer risks and non-cancer hazard quotients were predicted in under 4 yews of building year.

• 한국대기환경학회지
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• 제16권4호
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• pp.299-308
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• 2000

This study analyzed solid wastes generated from a school. The emission potential of hazardous pollutants generated from incineration of the school solid wastes (SSWs) was analyzed. Components of the SSWs were identified and the SSWs were classified into combustible and non-combustible wasts. The combustible wastes consisted of papers of 56.5^ plastics of 30.2% woods of 7.1% and fibers of 6.1% based on weight of the wastes. The moisture content and the ash content of the combustible wastes were 18~20% and 11~13% respectively. The combustible wastes of the SSWs were incinerated by using a small-scale incinerator. Fly and bottom ashes and volatile organic compounds (VOCs) were collected from the incineration. Also the metal leaching experiments on the fly and bottom ashes were performed, In analysis of metals leached from the ashes the total amounts of metals leached in the acid solution (pH=3) were much greater than those in the neutral solution (pH=5.8~6.2) For the same amounts of the fly and bottom ashes the total amounts of metals leached from the fly ashes were much greater than those from the bottom ashes. The VOCs produced from incineration of the SSWs consisted of aromatics of 42.1% aliphatic alkenes of 26.3% oxidized forms of 17.3% and aliphatic alkanes of 14.3% In addition the considerable amounts of hazardous air pollutants (e.g benzene chloro-benzene and chloro-alkanes) and compounds (e. g, aliphatic alkenes) with high potential of ozone or photochemical smog formation were identified from the incineration experiment of the SSWs.

• 센서학회지
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• 제22권4호
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• pp.249-255
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• 2013

Gas-sensor array technology, which has been much utilized in the field of food technology by the name of 'electronic nose' is drawing attention in diagnosing lung cancer based on the analysis of the exhaled human breath. Much understanding has been accomplished about the composition of the volatile organic compounds (VOCs) of the human exhaled breath, in spite of some variations depending on research groups due mainly to lack of the standardization of the sensing procedures. Since VOCs may be produced during the process of cellular metabolism, difference in the cellular metabolism between healthy cells and lung cancer cells are expected to be reflected on the composition variation of the exhaled VOCs. Several studies have attempted to apply the gas-sensor array technology to lung cancer analysis using many different types of sensors including metal oxide, carbon black-polymer composite, surface acoustic wave, and gold nanoparticles. In this mini-review VOC as biomarkers, sensor array technology and application of the array technology for the diagnosis of cancer disease have been described.

• Molecular & Cellular Toxicology
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• 제4권4호
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• pp.267-277
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• 2008

Benzene and ethylbenzene (BE), the volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Chronic exposure of benzene is responsible for myeloid leukemia and also ethylbenzene is also recognized as a possible carcinogen. To evaluate the BE effect on human, whole human genome 35 K oligonucleotide microarray were screened for the identification of the differential expression profiling. We identified 280 up-regulated and 201 down-regulated genes changed by more than 1.5 fold by BE exposure. Functional analysis was carried out by using DAVID bioinformatics software. Clustering of these differentially expressed genes were associated with immune response, cytokine-cytokine receptor interaction, toll-like signaling pathway, small cell lung cancer, immune response, apoptosis, p53 signaling pathway and MAPKKK cascade possibly constituting alternative or subordinate pathways of hematotoxicity and immune toxicity. Gene ontology analysis methods including biological process, cellular components, molecular function and KEGG pathway thus provide a fundamental basis of the molecular pathways through BEs exposure in human lymphoma cells. This may provides a valuable information to do further analysis to explore the mechanism of BE induced hematotoxicity.

• 한국입자에어로졸학회지
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• 제7권1호
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• pp.31-44
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• 2011

The hourly volatile organic compounds(VOCs) concentrations between 2005 and 2008 at Bulgwang photochemical assessment monitoring station were investigated to establish a method for quality assurance and quality control(QA/QC) procedure. Systematic error, erratic error, and random error, which was manifested by outlier and highly fluctuated data, were checked and removed. About 17.3% of the raw data were excluded according to the proposed QA/QC procedure. After QA/QC, relative standard deviation for representing 15 species concentrations decreased from 94.7-548.0% to 63.4-125.8%, implying the QA/QC procedure is proper. For further evaluation about the adequacy of QA/QC procedure, principal components analysis(PCA) was carried out. When the data after QA/QC procedure was used for PCA, the extracted principal components were different from the result from the raw data and could logically explain the major emission sources(gasoline vapor, vehicle exhaust, and solvent usage). The QA/QC procedure based on the concept of errors is inferred to proper to be applied on VOCs. However, an additional QA/QC step considering the relationship between species in the atmosphere needs to be further considered.