• 제목/요약/키워드: Particulates

검색결과 338건 처리시간 0.032초

저압용 절연재료의 염수분무 및 분진에 따른 특성비교 (The characteristics comparison of LV insulated materials based on the salt vaporization and the particulates)

  • 송길목;김영석;김선구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.1359-1360
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    • 2007
  • In this paper, it is described the characteristics comparison of LV insulated materials contaminated by the salt vaporization and the particulates. The contact angle of normal PVC is measured $75^{\circ}$ but its of PVC contaminated by the salt vaporization for 500 hours is measured $63^{\circ}$. The contact angle of normal bakelite is measured $66^{\circ}$ but its of bakelite contaminated by the salt vaporization for 500 hours is measured $44^{\circ}$. And the contact angle of normal acrylic resin is measured $65^{\circ}$ but its of acrylic resin contaminated by the salt vaporization for 500 hours is measured $60^{\circ}$. In the surface of insulated materials contaminated by the particulate, the contact angle is decreased. The surface of bakelite is not good as an insulator.

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자주달개비 미세핵 분석법을 이용한 작업환경내 총 먼지 중 수용성 추출물의 유전독성 평가 (Genotoxicity of Heavy Metals among the Particulates in the Working Environment as Assessed by Tradescantia-Micronucleus (Trad-MCN) Assay)

  • 신해식;김진규;이재환;황갑성;김균;이정주;이진홍
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.639-646
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    • 2003
  • In this study, we evaluated genotoxicity of heavy metals among particulates with Tradescantia-micronucleus (Trad-MCN) assay in the various working environment. In a synthetic fiber factory and a rubber factory, chromium concentration was higher than any other heavy metals. On the other hand, nickel concentration was the highest in a semi-conductor factory. The difference in genotoxicity among the working environment was statistically significant as Trad-MCN frequencies were 4.07 $\pm$0.35 MCN/100 tetrads (p< 0.01) for the synthetic fiber factory,5.73 $\pm$0.81 MCN/100 tetrads (p< 0.01) for the rubber factory, and 15.60$\pm$2.58 (p< 0.01) (p< 0.001) for the semi -conductor factory. As a result, heavy metals among particulates in the working environment can be considered to have hazardous potential to human health, although they cannot directly induce DNA damage to the workers in the working environments.

Distribution and Source of Atmospheric Polycyclic Aromatic Hydrocarbons and Nitropolycyclic Aromatic Hydrocarbons in Tieling City, Liaoning Province, a Typical Local City in Northeast China

  • Tang, Ning;Araki, Yuki;Tamura, Kenji;Dong, Lijun;Zhang, Xuemei;Liu, Qiuhua;Ji, Ruonan;Kameda, Takayuki;Toriba, Akira;Hayakawa, Kazuichi
    • Asian Journal of Atmospheric Environment
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    • 제3권1호
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    • pp.52-58
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    • 2009
  • Airborne particulates were collected in three different size fractions (>7 ${\mu}m$; 2.1-7 ${\mu}m$; < 2.1 ${\mu}m$) by using Andersen low-volume air samplers at three sites in Tieling city, Liaoning Province, a typical local city in northeast China, in every season during the period from July 2003 to May 2004. Nine polycyclic aromatic hydrocarbons (PAHs) and seven nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined by HPLC with fluorescence and chemiluminescence detection, respectively. The mean total concentrations of the nine PAHs and seven NPAHs were highest at The mixed residential and light industrial site, and lowest at the residential site near the suburbs. At all sites, more than 70% of the total PAHs and more than 60% of the total NPAHs were found in the finest particulate (< 2.1 ${\mu}m$) fraction. Both cluster analysis and several diagnostic ratios showed that the major contributors of PAHs and NPAHs in airborne particulates were coal combustion systems such as domestic stoves and coal boilers in all seasons in Tieling city.

다양한 위해성평가 방법에 따라 도출한 오염토양 선별기준의 차이에 관한 연구 (I): 매체 간 이동현상 해석에 따른 차이 (Analysis on the Risk-Based Screening Levels Determined by Various Risk Assessment Tools (I): Variability from Different Analyses of Cross-Media Transfer Rates)

  • 정재웅;류혜림;남경필
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제16권2호
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    • pp.12-29
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    • 2011
  • Risk-based screening levels (RBSLs) of some pollutants for residential adults were derived with risk assessment tools developed by United States Environmental Protection Agency (USEPA), American Society for Testing and Materials (ASTM), and Korea Ministry of Environment (KMOE) and compared each other. To make the comparison simple, ingestion of soil, dermal contact with soil, outdoor inhalation of vapors, indoor inhalation of vapors, and inhalation of soil particulates were chosen as exposure pathways. The results showed that the derived RBSLs varied for every exposure pathway. For direct exposure pathways (i.e., ingestion of soil and dermal contact with soil), the derived RBSLs varied mainly due to the different default values for exposure factors and toxicity data. When identical default values for the parameters were used, the same RBSLs could be derived regardless of the assessment tools used. For inhalation of vapors and inhalation of soil particulates, however, different analysis methods for cross-media transfer rates were used and different assumptions were established for each tool, identical RBSLs could not be obtained even if the same default values for exposure factors were used. Especially for inhalation of soil particulates pathway, screening level derived using KMOE approach (most conservative) was approximately 5000~10000 times lower than the screening level derived using ASTM approach (least conservative). Our results suggest that, when deriving RBSL using a specific tool, it is a prerequisite to technically review the analysis methods for cross-media transfer rates as well as to understand how the assessment tool derives the default values for exposure factors.

간접흡연의 정량적 노출측정 방법의 고찰 (Review of Various Quantitative Methods to Measure Secondhand Smoke)

  • 임수길;김정윤;임완령;손홍지;이기영
    • 한국환경보건학회지
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    • 제35권2호
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    • pp.100-115
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    • 2009
  • Secondhand smoke (SHS) is one of major public health threats. Since secondhand smoke is complex mixture of toxic chemicals, there has been no standardized method to measure SHS quantitatively. The purpose of this manuscript was to review various quantitative methods to measure SHS. There are two different methods: air monitoring and biological monitoring. Air monitoring methods include exhaled carbon monoxide level, ambient fine particulates, nicotine and 3-ethenylpyridine. Measurement of fine particulates has been utilized due to presence of real-time monitor, while fine particulates can have multiple indoor sources other than SHS. Ambient nicotine and 3-EP are more specific to SHS, although there is no real-time monitor for these chemicals. Biological monitoring methods include nicotine in hair, cotinine in urine, NNK in urine and DNA adducts. Nicotine in hair can provide chronic internal dose, while cotinine in urine can provide acute dose. Since biological monitoring can provide total internal dose, identification of specific exposure source may be difficult. NNK in urine can indicate carcinogenicity of the SHS exposure. DNA adducts can provide overall cancer causing exposure, but not specific to SHS. While there are many quantitative methods to measure SHS, selection of appropriate method should be based on purposes of assessment. Application of accurate and appropriate exposure assessment method is important for understanding health effects and establishing appropriate control measures.

공동주택 전열교환기 필터종류 및 두께에 따른 미세먼지 제거율 평가 (Evaluation of Particulate Matter Removal Rate according to Filter Type and Thickness of Total Heat Exchanger in Apartment Houses)

  • 송용우
    • 토지주택연구
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    • 제11권4호
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    • pp.93-98
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    • 2020
  • This study examined the particulate removal performance of three different types of air filters inside a heat exchanger. Of interest was the ability of each filter type in reducing the transmission of outdoor particulate matter of PM10 from entering an apartment while the heat exchanger was in operation. The study tested one commonly used medium filter (E11 grade) and two HEPA filters (H13 grade) of different thicknesses. Two different concentrations of particulate matter were used in the experiment to address different ambient air quality conditions in Korea, 32.75 ㎍/㎥ and 67.26 ㎍/㎥. Study results indicated that under the particulate matter concentration of 32.75 ㎍/㎥, all three filters were capable of removing more than 95% of the fine dust. However at a particulate matter concentration of 67.26 ㎍/㎥, the medium E11 grade filter was only able to remove about 90% of the particulates whereas the HEPA H13 grade filters were able to remove 95% or more of the particulates. The thicker HEPA filter (40T) was also more effective in removing particulates than the thinner HEPA filter (20T) by about 1.6 to 3 percentage points. Based on the findings of this study, it is recommended that HEPA filters of 20T thickness or greater be used during the high air pollution seasons of winter and spring in Korea while medium filters can be used during the other seasons to reduce outdoor air pollution transmission indoors.

미술대학 조소작업 중 발생하는 분진 및 소음에 대한 노출평가 (Exposure Assessment to Particulates and Noise among Sculptors at a College of Fine Art)

  • 조현우;윤충식;함승헌;이임규;박지훈;박동진;정진호;염종수;서규진
    • 한국환경보건학회지
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    • 제37권4호
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    • pp.267-278
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    • 2011
  • Objectives: A great number of hazardous agents can be emitted from various types of art-creation in a fine arts college, but little data on exposure assessment has been published. A variety of processes encompassing toxic or non-toxic materials, tools, and components are involved in a sculptor work at a fine art college. The aim of this study was to assess exposure levels to particulates and noise during sculpture classes in a college of fine arts. Methods: Students in sculpture classes participated in this study. Mass, number, and surface area concentrations of particulates, noise level, temperature and relative humidity were monitored by both personal and area sampling during the tasks of metal, wood, and stone sculpting. Results: The number and surface concentration of particulates was the highest in the task of wood sculpting, followed by metal and stone work. The mass concentration of particulates was the highest in stone sculpting (personal GM 3.0 mg/$m^3$, GSD 3.0), followed by wood (personal GM 1.5 mg/$m^3$, GSD 1.8) and metal work (personal GM 0.95 mg/$m^3$, GSD 1.51) in that order. Occupational exposure limits (OEL) for particulates depends on the type of particulate. For wood dust, 86% (six subjects) of the personal samples and all area samples exceeded the Korean OEL for wood dust (1 mg/$m^3$), while 20% (two subjects) among stone sculpting students were exposed above the Korean OEL (10 mg/$m^3$). In contrast, metal sculpting did not exceed the OEL (5 mg/$m^3$). For noise level, metal sculpting students (Leq 95.1 dB(A) in the morning, 85.3 dB(A) in the afternoon) were exposed the most, followed by stone sculpting (88.3 dB(A)), and wood sculpting (84.8 dB(A)) in that order. Compared with the 90 dB(A) of the Korean OEL and 85 dB(A) of the American Conference of Governmental Industrial Hygienists' threshold limit value (ACGIH-TLV) for noise, 100% of the subjects (five subjects) and area samples during metal sculpting in the morning session exceeded both OELs, but only three subjects (60%) exceeded the ACGIH-TLV in the afternoon session. For stone sculpting, 50% (one subject) and 100% (two subjects) exceeded the Korean OEL and ACGIH-TLV, respectively, but the area sample did not exceed either OEL. During wood sculpting, two subjects (40%) exceeded ACGIH TLV. Conclusions: This work evaluated the sculptors' exposure to particulate matter and noise in fine art college, and revealed a poor working environment for the participating students. Effective measures should be supplemented by the administration of colleges.