• Title, Summary, Keyword: styrene

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Toxicity of Styrene and Styrene-oxide in Embryos of the Japanese Medaka (Oryzias latipes) (Styrene 및 Styrene-oxide가 송사리 알의 초기발생 과정에 미치는 독성)

  • 박형숙;안혜원
    • Environmental health and toxicology
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    • v.15 no.3
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    • pp.61-67
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    • 2000
  • Toxic lesions of styrene in the Japanese Medaka (Oryzias latipes) were compared with those of styrene oxide, the active metabolite of styrene, using embryo-larval assays. The developmental stages of Japanese Medaka (Oryzias latipes) treated with both chemicals were not altered and progressed normally. However, styrene oxide was more toxic than styrene in terms of causing death and lesions . High concentrations of styrene (higher than 4.9 ppm) and styrene oxide (higher than 2.4 ppm), resulting in more than 50% mortality, caused similar lesions of cardiovascular system, craniofacial bone formation and spinal deformities, although a number of lesions were not observed by both chemicals . In the group treated with styrene, eyeball sizes and intereye distances were reduced, while, in the group treated with styrene oxide , the eyes and eye cups were not developed and two eyes were sometimes fused. In addition, styrene oxide caused the lesion which involved the posterior brain and brain stem were herniated through the spinal cord . The noticeable difference of toxic symptoms between these two chemicals was the time of onset. Toxicities of cardiovascular system and craniofacial bone formation appeared on day 3 of development in styrene oxide treated group, but, styrene treated group staned to show hemorrhages on day 3 and the craniofacial malformation were appeared on day 5, These differences between two chemicals may be due to the metabolism of styrene to styrene oxide, the reactive intermediate.

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Effects of Styrene-metabolizing Enzyme Polymorphisms and Lifestyle Behaviors on Blood Styrene and Urinary Metabolite Levels in Workers Chronically Exposed to Styrene

  • Kim, Ki-Woong
    • Toxicological Research
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    • v.31 no.4
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    • pp.355-361
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    • 2015
  • The aim of this study was to investigate whether genetic polymorphisms of CYP2E1, GSTM1, and GSTT1 and lifestyle habits (smoking, drinking, and exercise) modulate the levels of urinary styrene metabolites such as mandelic acid (MA) and phenylglyoxylic acid (PGA) after occupational exposure to styrene. We recruited 79 male workers who had received chronic exposure in styrene fiberglass-reinforced plastic manufacturing factories. We found that serum albumin was significantly correlated with blood styrene/ambient styrene (BS/AS), urinary styrene (US)/AS, and US/BS ratios as well as urinary metabolites, that total protein correlated with US/MA and US/PGA ratios, and that low density lipoprotein (LDL)-cholesterol significantly correlated with US/BS, US/MA, and US/PGA ratios. Multiple logistic regression analyses using styrene-metabolizing enzyme genotypes and lifestyle habits as dependent variables and blood and urine styrene concentrations and urine styrene metabolite levels as independent variables revealed that $CYP2E1^*5$ was associated with the MA/US ratio and GSTM1 with US/BS, that a smoking habit was associated with US/AS and MA/US ratios and MA and PGA levels, and that regular exercise was correlated with PGA/US. In conclusion, the results suggested that genetic polymorphisms of styrene-metabolizing enzymes, lifestyle behaviors, and albumin and LDL-cholesterol serving as homeostasis factors together are involved in styrene metabolism.

Characterization of Styrene Catabolic Genes of Pseudomonas putida SN1 and Construction of a Recombinant Escherichia coli Containing Styrene Monooxygenase Gene for the Production of (S)-Styrene Oxide

  • Park Mi-So;Bae Jong-Won;Han Ju-Hee;Lee Eun-Yeol;Lee Sun-Gu;Park Sung-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.16 no.7
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    • pp.1032-1040
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    • 2006
  • Some Pseudomonas species can grow on styrene as a sole carbon and energy source. From the new isolate Pseudomonas putida SN1, the genes for styrene catabolism were cloned and sequenced. They were composed of four structural genes for styrene monooxygenase (styA and styB), styrene oxide isomerase (styC), and phenylacetaldehyde dehydrogenase (styD), along with two genes for the regulatory system (styS and styR). All the genes showed high DNA sequence (91% to 99%) and amino acid sequence (94% to 100%) similarities with the corresponding genes of the previously reported styrene-degrading Pseudomonas strains. A recombinant Escherichia coli to contain the styrene monooxygenase from the SN1 was constructed under the control of the T7 promoter for the production of enantiopure (S)-styrene oxide, which is an important chiral building block in organic synthesis. The recombinant E. coli could convert styrene into an enantiopure (S)-styrene oxide (ee >99%) when induced by IPTG The maximum activity was observed as 140 U/g cell, when induced with 1 mM IPTG at $15^{\circ}C$.

Analysis of Rheological Properties for Styrene Copolymers (스티렌 공중합체의 유변학적 특성 해석)

  • 한민현
    • The Korean Journal of Rheology
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    • v.4 no.1
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    • pp.46-51
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    • 1992
  • 본 연구에서는 열가소성고무를 중심으로 한 스티렌 공중합체의 유변학적 특성을 Couette 보정치를 사용하여 해석하였다. 실험재료로는 SBS(Styrene-Butadiene-Styrene), SEBS(Styrene-Ethylene/Buthylene-Styrene), SIS(Styrene-Isoprene-Styrene)을 사용하였고 탄성체의 성격을 비교하기 위하여SBS(Styrene-Butadiene Rubber)와 IR(Isoprene Rubber)를 사용하였다, 실험결과 Couette 보정치는 온도가 증가할수록 감소하였다. 또한 열가소성 고부 (SBS, SEBS, SIS)의 보정치는 거의 비슷한 값을 나타내었으며 고무(IR, SBR)의 보정치는 열가소성고무에서보다 다소 높은 값을 나타내었다. 충진제를 첨가하였을 경우 충진제의 양 이 증가할수록 Couette 보정치는 감소하였다.

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Occupational Styrene Exposure on Auditory Function Among Adults: A Systematic Review of Selected Workers

  • Pleban, Francis T.;Oketope, Olutosin;Shrestha, Laxmi
    • Safety and Health at Work
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    • v.8 no.4
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    • pp.329-336
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    • 2017
  • A review study was conducted to examine the adverse effects of styrene, styrene mixtures, or styrene and/or styrene mixtures and noise on the auditory system in humans employed in occupational settings. The search included peer-reviewed articles published in English language involving human volunteers spanning a 25-year period (1990-2015). Studies included peer review journals, caseecontrol studies, and case reports. Animal studies were excluded. An initial search identified 40 studies. After screening for inclusion, 13 studies were retrieved for full journal detail examination and review. As a whole, the results range from no to mild associations between styrene exposure and auditory dysfunction, noting relatively small sample sizes. However, four studies investigating styrene with other organic solvent mixtures and noise suggested combined exposures to both styrene organic solvent mixtures may be more ototoxic than exposure to noise alone. There is little literature examining the effect of styrene on auditory functioning in humans. Nonetheless, findings suggest public health professionals and policy makers should be made aware of the future research needs pertaining to hearing impairment and ototoxicity from styrene. It is recommended that chronic styrene-exposed individuals be routinely evaluated with a comprehensive audiological test battery to detect early signs of auditory dysfunction.

Microbial styrene monooxygenase-catalyzed asymmetric synthesis of enantiopure styrene oxide derivatives (미생물 유래 Styrene monooxygenase를 이용한 광학활성 styrene oxide 유도체의 비대칭합성)

  • Lee, Eun-Yeol;Park, Sung-Hoon
    • KSBB Journal
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    • v.24 no.3
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    • pp.239-245
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    • 2009
  • Enantiopure styrene oxide derivatives are versatile building blocks for the synthesis of enantiopure pharmaceuticals. Styrene monooxygenase (SMO) catalyzes an asymmetric addition of an oxygen atom into a double bond of vinylaromatic compounds. SMO is a commercially potential biocatalyst to synthesize a variety of enantiopure epoxides with high enantiopurity and recovery yield. In this paper development of SMO biocatalyst and commercial feasibility of SMO-catalyzed asymmetric synthesis of enantiopure stylers oxide derivatives are reviewed.

Styrene-Mediated Oxidative Stresses in Rat Sperm Cells

  • Chun Young-Jin;Lee Hyun Min;Han Jee Hye;Oh Young Kun
    • Toxicological Research
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    • v.21 no.2
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    • pp.129-134
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    • 2005
  • Styrene is a commercially important chemical used mainly in the production of plastics. A toxic effect exerted by styrene exposure may cause infertility, congenital anomalies or death in offspring. Treatment with styrene for 0, 50, 100, and 500 mg/kg for 5 days in Sprague-Dawley rats significantly decreased sperm motilities and sperm counts while sperm abnormalities were significantly increased. To determine the relationship between changes in sperm motilities and roles of reactive oxygen species (ROS), we determined the effect of styrene on ROS production and mRNA expression of antioxidant enzymes in rats. ROS production was enhanced by styrene treatment in a dose-dependent manner. The mRNA expression of catalase and superoxide dismutase (SOD) 2 was strongly suppressed by styrene treatment although SOD1 or glutathione peroxidase (GPX) 4 expressions were not significantly changed. Taken together, these results indicate that styrene may cause toxic effect in rat sperm cells by enhancing oxidative stresses.

Evaluation of the Suitability of Establishing Biological Exposure Indices of Styrene

  • Choi, Ah-rum;Im, Sung-guk;Lee, Mi-young;Lee, Se-Hoon
    • Safety and Health at Work
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    • v.10 no.1
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    • pp.103-108
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    • 2019
  • Background: This study was designed to provide logical backgrounds for the revision of biological exposure indices (BEIs) for styrene exposure in Korea. In order to investigate the correlation between airborne styrene and biological exposure indices, we measured urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) in workers exposed to styrene occupationally, as well as airborne styrene at workplaces. Methods: Surveys were conducted for 56 subjects. The concentrations of airborne styrene and urinary metabolites of styrene were measured in 36 workers who were occupationally exposed to styrene, and in 20 controls. Air samples were collected using personal air samplers and analyzed by gas chromatography. Urine samples were collected at the end of the shift and analyzed by high performance liquid chromatography. Results: The geometric mean concentration of airborne styrene was 9.6 ppm. The concentrations of urinary MA, PGA, and MA+PGA in the exposure group were 267.7, 143.3, and 416.8 mg/g creatinine, respectively. The correlation coefficients for correlation between airborne styrene and MA, PGA, and MA+PGA were 0.714, 0.604, and 0.769, respectively. The sum of urinary MA and PGA corresponding to an exposure of 20 ppm styrene was 603 mg/g creatinine. Conclusion: The correlation of the sum of urinary MA and PGA with airborne styrene was better than the correlation of each individual urinary determinant. It is considered appropriate to amend the concentration of urinary MA+PGA to 600 mg/g creatinine as a BEI, which corresponds to an airborne styrene concentration of 20 ppm in Korea.

Improvement of Oxidative Stability for Non-fluorinated Membranes Prepared by Substituted Styrene Monomers (스티렌 유도체를 이용한 비불소계 고분자 전해질막의 산화적 안정성 개선)

  • Moon, Seung-Hyeon;Woo, Jung-Je;Fu, Rong-Qiang;Seo, Seok-Jun;Yun, Sung-Hyun
    • Membrane Journal
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    • v.17 no.4
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    • pp.294-301
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    • 2007
  • To improve oxidative stability of non-fluorinated styrene-based polymer electrolyte membranes, copolymerized membranes were prepared using styrene derivatives such as p-methylstyrene, t-butylstyrene, and ${\alpha}-methylstyrene$ by monomer sorption method. Prepared membrane was characterized by measurement of weight gain ratio, water content, ion-exchange capacity, proton conductivity, and oxidative stability under the accelerated condition. It was found that each step of monomer sorption method including sorption, polymerization and sulfonation could be affected by the properties and the structures of styrenederivatives. Due to difficulty of polymerization, ${\alpha}$-methylstyrene was copolymerized with styrene or p-methylstyrene. Prepared membrane using ${\alpha}-methylstyrene$ and styrene showed higher performance and stability comparing to copolymerized membrane with styrene. However, copolymerized membranes with ${\alpha}-methylstyrene$ did not showed much improved oxidative stability comparing to styrene membrane due to their lower molecular weight. The t-butylstyrene membrane showed a low performance due to substituted bulky-butyl group which prevents sorption and sulfonation reaction. However, copolymerized t-butylstyrene membranes with p-methylstyrene showed good performance and much improved stability than the styrene membranes.

Asymmetric resolution of racemic styrene oxide using recombinant Escherichia coli harboring epoxide hydrolase of Rhodotorula glutinis (Rhodotorula glutinis 유래의 고효율 재조합 Epoxide Hydrolase를 이용한 라세믹 Styrene Oxide의 비대칭 광학분할)

  • Park, Kyu-Deok;Choi, Sung-Hee;Kim, Hee-Sook;Lee, Eun-Yeol
    • KSBB Journal
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    • v.23 no.5
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    • pp.369-374
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    • 2008
  • The effects of reaction temperature and the addition of various detergents on the enantioselective hyrolysis activity of the recombinant Escherichia coli containing the epoxide hydrolase (EH) gene of Rhodotorula glutinis were investigated for the production of enantiopure styrene oxide. The recombinant E. coli harboring the EH gene from R. glutinis exhibited the enantiopreference toward (R)-styrene oxide with the maximum hydrolytic activity of $165.04{\mu}mol/min/mg$ of dry cell weight (dcw). The addition of 0.5% (w/v) Tween 20 at $10^{\circ}C$ increased the initial hydrolysis rate and enantioselectivity by 1.45-fold and 2.0-fold, respectively. Enantiopure (S)-styrene oxide was prepared with 99% ee enantiopurity and 46.0% yield (theoretical yield=50%) from 20 mM racemic styrene oxide.