• 제목/요약/키워드: Benzene

검색결과 1,928건 처리시간 0.028초

Indolent B-Cell Lymphoid Malignancy in the Spleen of a Man Who Handled Benzene: Splenic Marginal Zone Lymphoma

  • Lee, Jihye;Kang, Young Joong;Ahn, Jungho;Song, Seng-Ho
    • Safety and Health at Work
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    • 제8권3호
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    • pp.315-317
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    • 2017
  • We present the case of a 45-year-old man with a history of benzene exposure who developed splenic marginal zone lymphoma. For 6 years, he had worked in an enclosed space cleaning instruments with benzene. He was diagnosed with splenic marginal zone lymphoma 19 years after retirement. During his time of working in the laboratory in the 1980s, working environments were not monitored for hazardous materials. We indirectly estimated the cumulative level of past benzene exposure using job-exposure matrices and technical assumptions. Care must be taken in investigating the relevance of occupational benzene exposure in the occurrence of indolent B-cell lymphoma. Because of the long latency period and because occupational measurement data do not exist for the period during the patient's exposure, the epidemiological impact of benzene exposure may be underestimated.

Predicting Atmospheric Concentrations of Benzene in the Southeast of Tehran using Artificial Neural Network

  • Asadollahfardi, Gholamreza;Mehdinejad, Mahdi;Mirmohammadi, Mohsen;Asadollahfardi, Rashin
    • Asian Journal of Atmospheric Environment
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    • 제9권1호
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    • pp.12-21
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    • 2015
  • Air pollution is a challenging issue in some of the large cities in developing countries. In this regard, data interpretation is one of the most important parts of air quality management. Several methods exist to analyze air quality; among these, we applied the Multilayer Perceptron (MLP) and Radial Basis Function (RBF) methods to predict the hourly air concentration of benzene in 14 districts in the municipality of Tehran. Input data were hourly temperature, wind speed and relative humidity. Both methods determined reliable results. However, the RBF neural network performance was much closer to observed benzene data than the MLP neural network. The correlation determination resulted in 0.868 for MLP and 0.907 for RBF, while the Index of Agreement (IA) was 0.889 for MLP and 0.937 for RBF. The sensitivity analysis related to the MLP neural network indicated that the temperature had the greatest effect on prediction of benzene in comparison with the wind speed and humidity in the study area. The temperature was the most significant factor in benzene production because benzene is a volatile liquid.

The Effect of Benzene on the Activity of Adenosine Deaminase in Tissues of Rats

  • Turhan, Ali;Dere, Egemen
    • BMB Reports
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    • 제40권3호
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    • pp.295-301
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    • 2007
  • Swiss Albino (Rat rattus norvegicus) rats were intraperitoneally injected with a 100 mg $kg^{-1}$ dosage of benzene, a toxic and carcinogenic agent widely used for industrial purposes. Changes in the adenosine deaminase (ADA) activity in the liver, kidney and serum of rats were investigated at 0, 2, 4, 8, 16, 32 and 64 h following injection. Serum physiological was administered to each control group. Enzyme activities were measured spectrophotometrically. Our purpose was to further investigations of some diseases caused by benzene, and present evidence of variations in the activity of ADA enzyme effected by benzene. While benzene caused significant inhibitions in ADA activity in the liver at 16 and 32 h and at 0.05 probability level, no significant inhibition or activation occurred at other test periods (hours). ADA activity did not present any significant variation in the kidneys. It was observed that ADA activity displayed similar patterns in the control groups. Comparisons of ADA activities in the two groups showed a statistically significant decrease between $4^{th}$ and $64^{th}$ hours (p< 0.05), demonstrating a direct correlation between benzene and its effects on ADA enzymes.

벤젠 대사에 있어서 CYP2E1유전자다형성의 영향 (Influences of CYP2E1 Gene Polymorphism on the Metabolism of Benzene)

  • 정효석;김기웅;장성근
    • Toxicological Research
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    • 제18권4호
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    • pp.325-330
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    • 2002
  • In this study, the biochemical role of genetic polymorphism in modulating urinary excretion of benzene metabolite as phenol level has been investigated in 90 workers exposed to benzene in the petroleum refinery plant of Korea. The mean concentration of volatile benzene in the refinery environment was 0.042 mg/㎥ (SD, 0.069) and that of urinary phenol was 7.42 mg/g creatinine (SD, 11.3). The frequencies of CYP2E1 genotypes, namely CYP2E1$^*1$/$^*1$, CYP2E1$^*1$/$^*2$ and CYP2E1$^*2$/$^*2$ were 2.2% (2 subjects), 6.7% (G subjects) and 91.1% (85 subjects), respectively, and allele frequencies for CYP2E1$^*1$ and CYP2E1$^*2$ were 0.06 and 0.94. The airborne benzene concentration was significantly related to the concentration of phenol in urine (r = 0.640, p < 0.01). The urinary phenol level was significantly correlated with CYP2E1$^*2$/$^*2$ (r = 0.590, p < 0.05). The various biological (i.e. age and liver function parameters) or lifestyle factors (i.e. medication, smoking, alcohol and coffee intake), also taken into account as potential confounders, did not influence the correlation found. These results suggested that CYP2E1 genotypes might play an important role in the metabolism of benzene.

TMA-Zeolite Comphx 에 의한 수용액(水溶液)중 Benzene 제거(除去) (Removal of benzene from aqueous solution by TMA-Zeolite complex)

  • 이창일;이동훈;최정
    • 한국환경농학회지
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    • 제17권1호
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    • pp.43-47
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    • 1998
  • 한국산(韓國産) 천연(天然) zeolite에 양이온 계면활성제(界面活性劑)인 TMA(Tetrametyl ammonium)를 흡착시킨 TMA-zeolite complex로 수용액 중의 휘발성 유기화합물인 benzene을 흡착시켜 제거하는 실험을 행하였다. 천연 zeolite의 CEC는 95.9 cmol/kg이었고, X-선 회절분석과 IR분석 결과 clinoptilolite와 mordenite가 주성분이었다. TMA는 zeolite표면에 CEC의 약 8% 정도가 신속히 흡착되었으며 이와 같이 TMA를 흡착한 TMA-zeolite complex에 의하여 수용액중의 benzene이 효과적으로 제거(除去)되었다.

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벤젠의 점성도에 대한 온도와 압력의 영향 (Effect of Temperature and Pressure on the Viscosity of Benzene)

  • 김정림;경진범;유미현
    • 대한화학회지
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    • 제37권12호
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    • pp.1003-1009
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    • 1993
  • 여러 온도와 압력에서 벤젠의 점성도를 결정하여, 액체 벤젠의 점성도에 미치는 온도와 압력의 영향에 대하여 연구하였다. 여러 온도와 압력으로 유지되고 있는 일정한 밀도의 벤젠 속에서 공 낙하 시간을 측정함으로써 벤젠의 점성도를 산출할 수 있었다. 그 결과로부터 벤젠의 비부피에 미치는 온도와 압력의 영향, 자유부피에 미치는 온도와 압력의 영향에 대해서 알아보았으며, 결론적으로 벤젠의 점성도에 대한 온도와 압력의 영향을 온도와 압력의 변화에 따르는 자유부피의 변화에 의하여 고찰하였다.

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메탄, 벤젠 및 톨루엔 제거용 바이오커버의 세균 군집 특성 (Characterization of the Bacterial Community in a Biocover for the Removal of Methane, Benzene and Toluene)

  • 류희욱;조경숙
    • 한국미생물·생명공학회지
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    • 제40권1호
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    • pp.76-81
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    • 2012
  • Removal of methane, benzene and toluene was evaluated in a lab-scale biocover packed with a soil mixture of forest soil and earthworm cast (75:25 weight ratio). The bacterial community in the biocover was characterized using quantitative real-time PCR and terminal restriction fragment length polymorphism. Methane was removed at the upper layer of the biocover (-0.1 ~ -0.4 m), where the oxygen concentration was remarkably lower. The average removal efficiencies for methane and benzene/toluene were 90% and 99%, respectively. The pmoA gene copy numbers, responsible for methane oxidation, in the upper layer were higher than those in the lower layer. While type I methanotrohs dominated the lower layer, type II methanotrophs, such as Methylocystis and Methylosinus, were noted to be predominant in the upper layer. Benzene and toluene were removed from the lower layer (-0.6 ~ -0.9 m) as well as the upper layer. Moreover, the tmoA gene copy number, responsible for benzene/toluene oxidation, seen in the upper layer was not significantly different from those seen in the lower layer. These results suggest that a biocover packed with a soil and earthworm cast mixture is a promising method which could be utilized for the control of methane and volatile organic compounds such as benzene and toluene.

국내 이동오염원에서 발생되는 벤젠 배출량 산정 (Estimation of Benzene Emissions from Mobile Sources in Korea)

  • 이주형;차준석;홍지형;정동일;김지영
    • 한국대기환경학회지
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    • 제24권1호
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    • pp.72-82
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    • 2008
  • Benzene is a very harmful and toxic compound known as human carcinogen by all routes of exposure. Owing to the risky feature of benzene, several countries such as Japan, UK and EU have established the ambient air quality standard and protect from that risk of it. Korea also has designated it as one of the criteria air pollutants and established the concentration limit ($5\;{\mu}g/m^3$) in the air and is going to apply the standard from 2010. Benzene is emitted from various sources such as combustion plants, production processes, waste treatment facilities and also automobiles. Mobile source is known as one of the major emission sources of benzene. In this study, we estimated the domestic emissions of benzene from mobile source and compared the results with those of advanced countries. Mobile source was divided into 2 categories, Le., on-road source and non-road source. The total emissions of benzene from mobile source were estimated as 3,106 tons/yr and 1,612 tons/yr was emitted from on-road source and 1,494 tons/yr was from non-road source. Emission ratio of benzene from on-road source showed that 80.0% was from passenger cars, 10.1% was from taxis, 7.2% was from light-duty vehicles, 2.5% was from heavy-duty vehicles and 0.2% was from buses. In the case of non-road source, the distribution showed that 66.3% was from construction machineries, 14.5% was from locomotives, 11.7% was from ships, 7.1% was from agriculture equipments and 0.5% was from aircrafts. The cold-start emissions were estimated as 942 tons/yr and this value was almost 1.5 times greater than that for hot engine emissions (608 tons/yr). In addition, the fuel-based distribution was 65.9%, 31.1% and 2.8% from gasoline, LPG and diesel vehicles, respectively. The emission ratio from mobile source occupied 65% and 30% of total benzene emissions in USA and UK, respectively. In case of Korea, the emission ratio of benzene from mobile source occupied 29% (15% from on-road source, 14% from non-road source) which showed similar value with UK.

Isentropic Compressibility for Binary Mixtures of Propylene Carbonate with Benzene and Substituted Benzene

  • Wankhede, D.S.
    • 대한화학회지
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    • 제56권1호
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    • pp.7-13
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    • 2012
  • Ultrasonic velocities (u) for binary mixtures of propylene carbonate (PC) (1) with benzene and substituted benzenes (2) viz. benzene, ethylbenzene, o-xylene and p-xylene have been measured at 288.15-308.15 K over the entire range of composition. The experimental values of ultrasonic velocities (u) have been utilized to calculate isentropic compressibility ($K_s$), intermolecular free length ($L_f$), acoustic impedance (Z).

내성(耐性) 라텍스를 이용한 도공지(塗工紙)의 인쇄적성(印刷適性)에 관한 연구(硏究)(I) - 라텍스필름에서 벤젠환의 배향성(配向性) - (Studies on Printability of Amphoteric Latex-Based Coated Paper(I) - Orientation of Benzene Ring in the Latex Film -)

  • 이용규
    • Journal of the Korean Wood Science and Technology
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    • 제22권1호
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    • pp.80-84
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    • 1994
  • The orientation of bezene ring in latex film was investigated with raman spectroscopy. The benzene ring of anionic latex ran parallel with the film surface of latex, whereas that of amphoteric latex did not. Consequently, it showed the possibility of interactions or interrelations between the orientation of benzene ring and ink, contact angle, printability and so on.

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