• Safety and Health at Work
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• 제10권2호
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• pp.229-236
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• 2019

Background: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. Methods: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. Results: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from $4.1{\times}10^{10}$ (Ultem filament) to $2.2{\times}10^{11}$ [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (${\mu}g/min$) ranged from $1.9{\times}10^4$ (acrylonitrile butadiene styrene and polycarbonate) to $9.4{\times}10^4$ (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open ($2.3{\times}10^{10}number/min$) than when the lid was closed ($1.5-5.5{\times}10^9number/min$); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. Conclusion: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

• Journal of the Korean Wood Science and Technology
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• 제42권6호
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• pp.747-757
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• 2014

건축재료와 생활용품으로부터 방출되는 실내공기 오염물질들로 인한 피해가 증가하고 있는 현시점에서 친환경 제품에 대한 관심이 높아지고 있다. 이러한 관심 속에 피톤치드에 대한 효능이 알려지면서 다양한 방법으로 사용되고 있다. 피톤치드를 다량 함유한 편백잎 증류추출수의 가습시 발생하는 휘발성유기화합물의 방출특성을 GC-MS를 이용하여 그 효과를 조사하였다. 편백잎추출수 가습시 115종의 화합물이 검출되었다. 검출된 화합물들은 aromatic compound, terpenoid, alkane, ketone, ester, aldehyde, alcohol, acid, miscellaneous compound류로 분류하였으며 aromatic compound류(13종, 38%)와 terpenoid류(23종, 33%) 화합물이 다른 화합물류에 비해 높은 비율로 검출되었다. Aromatic compound류 경우 편백잎추출수에 의한 추가 화합물은 검출되지 않아 그 영향이 없는 것으로 판단되며, terpenoid류 경우 편백잎추출수 가습시 10% 정도 증가하였고 7종의 화합물이 추가로 검출되었다. 편백잎추출수 가습시 방출된 terpenoid류 화합물들은 항균, 방충, 방부 효력뿐만 아니라 항고혈압성과 항암에 효과가 있는 것으로 알려져 있어 건강에 도움을 줄 것으로 판단된다.

• 한국가구학회지
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• 제20권3호
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• pp.198-204
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• 2009

Less used small diameter logs of black locust were heated at $250^{\circ}C$ for improving utilization. The volatile compounds emitted by the heated logs were analyzed. Their effect of formaldehyde absorption was evaluated with PB. Ester and acid compounds were dominant in content. Especially, methyl acetate and acetic acid showed the highest contents. The total content of aromatic compounds decreased as heating time increased. Amoung ketone compounds, The contents of 2-propanone, 2-pentanone, 3-petanone, 3-hexanone and cyclopentenone decreased with the increase of heating time, but the others did not. The contents of the chemicals, furfural and 3-pentanol, increased with heating time, while that of 2-methyl butanal decreased. It was hard to say that formaldehyde was absorbed by the heated black locust samples. Some decorative goods were designed with the heated logs.

• 한국환경보건학회지
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• 제43권6호
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• pp.457-466
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• 2017

Objectives: This study was carried out to investigate the characteristics of volatile organic compounds (VOCs) emitted from sewerage facilities such as a sanitary sewers, outlets, and catch basins. In addition, the dominant malodorous VOCs among the compounds in this study were studied. Methods: Waste gas samples were collected at 27 points in a sanitary sewer in commercial and residental areas. The concentrations of seven volatile organic compounds, including benzene and toluene, in the samples were analyzed by gas chromatograph mass spectrophotometer (GC/MS). Odor concentrations were estimated using the concentration data of the VOCs and each compound's threshold limit value. Results: As a result, it appeared that the average concentration of total observed data for acetaldehyde was 15.98 ppb and benzene 1.87 ppb, toluene 82.31 ppb, ethyl benzene 63.12 ppb, m+p-xylene 15.66 ppb, oxylene 18.73 ppb, and styrene 4.39 ppb. VOC concentrations in the commercial area were higher than those in the residential area. VOC concentrations of waste gas emitted from sewer lines was also higher than those at the outlet and in the catch basins. It was estimated that the main malodorous VOC among the seven VOCs was acetaldehyde. Conclusions: As there is little data on VOC concentrations inside sewer facilities in Korea, these data will be helpful for estimating impact assessment of VOCs and establishing a counter-plan for the abatement of VOCs from sewer facilities in the future.

• 한국환경교육학회지:환경교육
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• 제24권3호
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• pp.18-25
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• 2011

This study was conducted to evaluate the effects of volatile organic compounds and formaldehyde of newly-built school classroom indoor air on the neurobehavioral functions of students. The elementary schools that were opened in September 2008(as of September 2008) was selected for newly-built school and the elementary school that were opened in March 2006 was selected for control group schools. The concentration of formaldehyde(HCHO), a hazardous organic compound that exists in the air of classrooms, exceeded the standard value of $108.2{\mu}g/m^3$ in newly-built schools while it was $60.8{\mu}g/m^3$ in control group schools, which is around 60% of the standard concentration. However, the concentration of the total volatile organic compounds(TVOCs) was $788.9{\mu}g/m^3$ and $756.1{\mu}g/m^3$ in newly-built schools and control group schools respectively, which are approximately two times higher than the standard concentration. In newly-built schools, the mean reaction time of additions and symbol digit, respectively 3,020ms and 2,398ms in pre-exposure were increased to 3,167ms and 2,514ms respectively in post-exposure. The difference of mean reaction time between pre and post exposure was 146.8 ms, or 4.6%, and 116.7ms, or 4.8%, respectively, showing statistically-significant increase of reaction time(p<0.05). On the contrary, the difference of reaction time of both tests were not statistically significant in the control group schools. These results showed that the neurobehavioral performance of newly-built schools students were affected by volatile organic compounds and formaldehyde of classroom indoor air.

• Elastomers and Composites
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• 제54권4호
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• pp.294-298
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• 2019

A three-layered PVC sheet consisting of polyvinyl chloride (PVC) and woven polyester fabric was prepared by extrusion and calendering. The flexibility and durability of the PVC were tuned by adding plasticizers, additives, and surface coatings. The tensile and tear strengths of the three-layered PVC sheet were higher than those of commercial two-layered sheet, while exhibiting low weight. The concentrations of the total volatile organic compounds (TVOCs) and formaldehyde (HCHO) emitted from the sheet were also lowered. The PVC sheet remained stable after prolonged exposure to UV light, signifying that the PVC sheet is suitable for cargo screen applications.

• 교육녹색환경연구
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• 제6권2호
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• pp.66-90
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• 2007

The purpose of this study is to measure and analyze primary causes of indoor air pollution, including carbon dioxide, minute dust, and total volatile organic compounds, for each room before the beginning of a class through the time of discharge after the end of the class in general classrooms, computer rooms, and science rooms of three newly-established schools that opened in 2006, examine properties of indoor air environment in each room by educational activities at school, and determine effective management schemes; the results of this study can be summarized as follows: 1) As for implications for each item found in the mean for each place, since minute dust (PM10) was more likely to occur in time slots full of students' activities, such as a traveling class and a recess, than in the middle of a class and could be expected fully, it is necessary to make a scheme for cleaning in order to reduce minute dust within a room, for example, by usually using a vacuum cleaner indoors. 2) While carbon dioxide was expected to vary with the differences in the amount of breath between higher-graders and lower-graders in a general classroom but showed insignificant difference by grades, showing differences in pollution by four times at a maximum according to the opening of a window as expected, it is necessary to implement artificial or natural ventilation and take a positive measure, for example, by presenting a concrete ventilation scheme, in order to improve indoor air pollution at a room practice. 3) Total volatile organic compounds were found to exceed the standard by more than twice in general classrooms, science rooms, and computer rooms of the schools because of building materials, furnitures including desks and chairs, panels and boards for environment beautification, and items which could be detected even from students' clothes; while a field directly-reading tool was used, obtaining high reliability for the results, it is necessary to apply an analytical method based on process test separately for actual correct measurement if a significantly great amount of total volatile organic compounds appear as compared with other schools due to measuring expenses and consecutive measurements. 4) Since formaldehyde (HCHO) was generally found to exceed the standard in general classrooms, science rooms, and computer rooms, it is necessary to establish and operate a ventilator during a class in a computer room which requires airtightness and a science room in which an organic compound should be used for a class.

• Environmental Analysis Health and Toxicology
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• 제17권2호
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• pp.147-160
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• 2002

Volatile organic compounds (VOCs) are an important public health issue in Korea and many important questions remain to be addressed with respect to assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in their analytic determination Valid Personal exposure assessment methods are needed to evaluate exposure frequency, duration and intensity, as well as their relationship to personal exposure characteristics. Biological monitoring is also important since it may contribute significantly in risk assessment by allowing the estimation of effective absorbed doses. This study was on ducted to establish the environmental measurement, personal dosimetry and biological monitoring methods for VOCs. These methods are needed to compare blood, urinary and exhalation breath VOC levels and to provide tools for risk assessment of VOC exposure. Passive monitors (badge type) and a active samplers (trap) for the VOCs collection were used for air sampling. Methods development included determining the minimum detectable amounts of VOCs in each media, as well as evaluating collection methods and developing analytical procedures. Method reliability was assessed by determining breakthrough volumes and comparing results between laboratories and with other methods. A total capacity of trap used in this study was 60ι. Although variable by compound, the average breakthrough was 20％. Also, there was no loss of compounds in trap even if keep for 45 day in -7$0^{\circ}C$. The recovery of active and passive methods was 69％ ~ 126％ and method detection limit was 0.24 $\mu\textrm{g}$/trap and 0.07 $\mu\textrm{g}$/badge. There was no statistical difference (P > 0.05) between active and passive methods.

• Journal of the Korean Wood Science and Technology
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• 제30권4호
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• pp.80-86
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• 2002

졸참나무 (Quercus serrata), 맹종죽 (Phyllostachys pubescens) 및 소나무 (Pinus densiflora)로부터 제조한 미정제 초액의 휘발성 성분을 고상(固相) 미량추출(solid phase microextraction; SPME)법을 이용하여 분석하였다. 이들 초액 중의 휘발성화합물 분석을 위하여 극성 (CBP 20) 및 무극성 (CBP 1) 칼람을 사용하였으며, 이로부터 총 264개의 피크를 검출하였다. 이들 성분들 중 주요 화합물은 2-butanone, acetic acid, guaiacol, phenol, 4-ethyl guaiacol, cresol류, 4-ethyl phenol, 그리고 syringol이었다. 무극성 칼람을 사용함에 의하여 7개의 성분, 즉, 1-hydroxy-2-butanone, ethisolide, furfuryl acetate, 1-(2-furanyl)-1-propane, 1,2-dimethoxybenzene, 1,2-dimethoxybenzyl alcohol, phenyl acetate를 새로이 동정할 수 있었다. 이 성분들 중 페놀류가 주성분이었으며, 휘발성 성분의 49~65%를 차지하였다. 죽초액의 경우 페놀류의 비율은 다른 두 목초액보다 낮았다. 그러나 중성화합물류 및 유기산류는 소나무 및 졸참나무로부터 제조한 목초액보다 그 비율이 더 높았다. 따라서 이들 죽초액과 목초액 간의 훈취의 차이는 목초액의 서로 다른 휘발성분의 함유량의 차이에 기인한다고 생각된다.

• 한국식품영양과학회지
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• 제46권7호
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• pp.822-832
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• 2017

돼지감자의 품종별 유기산, 유리당 함량 및 휘발성 향기성분을 측정한 결과는 다음과 같다. 돼지감자에 함유된 유기산은 citric acid, malic acid, succinic acid였으며, malic acid의 함량이 가장 높았고 다음으로 citric acid로 나타났다. 총유기산 함량은 흰색이 2,065 mg/100 g, 자색은 2,482 mg/100 g으로 자색 돼지감자의 함량이 유의적으로(P<0.05) 높았다. 유리당은 sucrose, fructose, glucose로 나타났으며, sucrose의 함량이 가장 높았고 총유리당 함량은 흰색이 24.95 g/100 g, 자색이 11.57 g/100 g으로 나타나 흰색 돼지감자의 총유리당 함량이 유의적으로(P<0.05) 높게 나타났다. 휘발성 향기성분에서 돼지감자는 품종별, 처리방법과는 관계없이 acid류 5종, alcohol류 13종, aldehyde류 19종, hydrocarbon류 12종, ketone류 15종, 기타 8종, pyrazine류는 27종, terpene류는 18종이었으며, 총 117개의 휘발성 성분이 확인되었다. 돼지감자에는 terpene류가 가장 많았으며, terpene류 중에서는 ${\beta}$-bisabolene이 주된 성분이었다. 두 번째로 많은 화합물은 aldehyde류였으며, hexanal이 가장 높게 나타났다. 처리방법에 따른 차이로 볶은 시료에서는 pyrazine류가 대부분을 차지하였으며, 2,5-dimethyl-3-ethylpyrazine이 가장 높았고 다음으로 2,5-dimethylpyrazine으로 나타났다. 자색시료보다 흰색시료에 함량이 높은 화합물은 aldehyde류, hydrocarbone류였으며, 흰색시료보다 자색시료에 많은 화합물은 terpene류와 alcohol류로 나타났다.