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PubMedDate not supplied

Global migration from styrenics to liquid food simulants.

Chemical inertness of typical styrene polymers used in food packaging was investigated by "global migration" measurements. Absorption of liquid food simulants by plastics was also studied. Migrated compounds, detected and identified by gaschromatography-mass spectrometry (GC-MS), are styrene (monomer) and styrene dimers. All migration values, measured under different experimental conditions, turn out to be lower than the overall migration limit, as fixed by current legislation.

Absorption↗
PubMed1989

[The effects of inhalation of styrene on the neurobehavior in the offsprings].

Pregnant Wistar rats were exposed to 0.60 +/- 18.9, 297.7 +/- 72.4 ppm styrene for 6 hours/day during 7 to 21 days of gestation. No significant differences among groups were found in the length of gestation or in the number of offspring delivered. Several neurobehavioral tests detected differences in the offspring exposed to styrene during gestation from controls. Even exposure to relatively low concentrations of styrene delayed some physiological developments, in addition to causing disturbances of the neuromotor coordination function (Rota-Rod performance) and learning acquisition (CRF). Furthermore, large dose led to subtle changes in emotional behavior and increases in spontaneous activities in addition to the delay of neurobehavioral developments.

Animals↗
PubMed1977

Characterization of rat lung epoxide (styrene oxide) hydrase with a modified radioactive assay of improved sensitivity.

The epoxide hydrase assay developed by Oesch et al. (Biochim. Biophys. Acta, 227: 685-691, 1971) using [3H]styrene oxide as substrate was modified in three ways for use with rat lung microsomes: the substrate was purified before use, the volume of the incubation mixture was scaled down 4-fold, and the incubation time was extended to 45 min (activity was found to be linear for at least 60 min). These modifications increased the sensitivity of the assay procedure 75- to 150-fold. The procedure was found to be linear with lung microsomal protein up to at least 1.8 mg protein per incubation mixture. This modified assay for epoxide hydrase was used to characterize the enzyme in rat lung. Its apparent vmax is 0.5 nmole of styrene glycol formed per min per mg microsomal protein, and its apparent Km was 0.11 to 0.25 mM. The pH optimum is around 9.7. Upon subcellular fractionation of lung tissue, expoxide hydrase distributes in the same manner as a marker for the endoplasmic reticulum (reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase) and in a different way from markers for the nuclei, mitochondria, concentric lamellar organelles, lysosomes, Golgi membranes, plasma membrane and soluble cytoplasm. The specific activity of epoxide hydrase in rough and smooth lung microsomes is aobut the same. Treatment i.p. of rats with methylcholanthrene (3 injections of 20 mg/kg), phenobarbital (5 daily injections of 80 mg/kg) or styrene oxide (5 daily injections of 40 mg/kg), did not induce lung microsomal epoxide hydrase activity. 1,1,1-Trichloropropene 2,3-oxide was shown to be an uncompetitive inhibitor, and cyclohexene oxide was a noncompetitive inhibitor of this enzyme. Ethanol and butanol activate the epoxide hydrase of lung microsomes at low concentrations and inhibit it at higher concentrations.

Alcohols↗
PubMed1979

Whole-body autoradiography and allied tracer techniques in distribution and elimination studies of some organic solvents: benzene, toluene, xylene, styrene, methylene chloride, chloroform, carbon tetrachloride and trichloroethylene.

Whole-body autoradiography has been used to study the distribution and fate of 14C-labeled benzene, toluene, xylene, styrene, methylene chloride, chloroform, carbon tetrachloride and trichloroethylene in mice after inhalational exposure. Total radioactivity, including the volatile part of the solvents were registered by autoradiography of dried, evaporated tape-fastened sections. In addition, dried, evaporated tape-fastened sections were extracted with water, trichloroacetic acid and a series of organic solvents and autoradiographed to register organs where metabolites were firmly bound. In another facet of the study, the quantitative elimination of the solvents and their metabolites via various routes was investigated. The expiration of unchanged solvents was subject to mathematical and computerized compartmental pharmacokinetic analysis. All solvents were rapidly taken up in fatty and nervous tissues where they were retained for different periods of time largely dependent on their fat solubility. Unexpectedly long retention times were noted for the chlorinated solvents, particularly for chloroforn, which showed a specific long-term retention in the cerebellum, meninges and spinal nerves, indicating interactions with specific nervous tissue receptors. Solvent metabolites appeared rapidly in several organs, mainly the liver and kidney, and were excreted both via urine and bile. Toluene and xylene metabolites were completely extractable whereas firmly bound metabolites were registered after inhalation of benzene, styrene and all chlorinated solvents, notably in the liver and kidney but also in the bronchi of the lung. Three-compartment pharmacokinetics were observed for the majority of the solvents selected for study although a two-compartment model was found to fit the elimination rate curves for styrene, methylene chloride and chloroform in the exhaled air. The fat solubility of the solvents was found to influence their pharmacokinetics since lower rate constants were generally obtained for the expiration of more fat soluble solvents.

Adipose Tissue↗
PubMed1984

Congenital malformations, mortality and styrene exposure.

The prevalence of congenital malformations among children born to styrene-exposed male and female workers, as well as the mortality of the exposed workers, was studied. A cohort of 2,209 workers (1,698 men, 511 women) was selected from the personnel files of 160 workplaces using styrene in the manufacture of reinforced plastic products. The earliest exposure histories began in 1960, but the majority of workers had been exposed after 1967. The data on children born to the exposed workers were linked with those of the Register of Congenital Malformations. The number of malformations of children born to the workers was, both before and during the styrene exposure, below the expected values. In the cohort there were 37 observed deaths (expected 74.0), six of which were due to cancer (expected 13.0). The cancer sites were the stomach (2 cases), bronchus (1), breast (1), ovary (1), and kidney (1 case). There were no cases of lymphatic or haematopoietic cancer. Most of the cancers appeared after short exposure times and soon after the commencement of exposure.

Abnormalities, Drug-Induced↗
PubMed1981

[Functional-morphologic features of the adrenal cortex in white rats during protracted exposure to styrene].

Experiments on rats showed that long-term styrene exposure suppresses both specific and nonspecific cell metabolic indices in different adrenocortical areas. However, the sensitivity of the different areas proved to vary under styrene exposure. This allows the suggestion that each area undergoes different degree of damage which brings about the disturbance of optimum correlations between various functions of the adrenal cortex. Administration of metapirone during the first weeks of exposure diminishes the main effect of styrene. It is concluded that one of the possible factors leading to the development of abnormalities under chronic exposure to aromatic hydrocarbons may involve the breach of the correlations between different structural components of the adrenal cortex thereby favouring the maintenance of the whole body discordance.

Acid Phosphatase↗
PubMed1980

The problem of negative results for styrene in the in vitro mutagenesis test with metabolic activation (microsomal assay). - 2. Behaviour of epoxide hydrolase in the incubation mixtures.

The behaviour of epoxide hydrolase and monooxygenase was studied in incubation mixtures for the in vitro mutagenesis test with metabolic activation (microsomal assay) both in the presence and in absence of styrene 50mM. Epoxide hydrolase activity was much more stable than monooxygenase in all tested systems (S-9 fractions or microsomes of rats or mice, males or females) both in the presence and in absence of styrene. Membrane bound epoxide hydrolase was slightly less stable than the soluble one. These results further substantiate the explanation for the negative results of in vitro mutagenesis tests with styrene.

Aminopyrine N-Demethylase↗
PubMed1978

Monitoring of styrene exposure in the polyester industry.

Obtaining reliable results of exposure to styrene in field studies requires an appropriate methodology not only for analytical methods but also for the main strategy of conducting the surveys. This paper briefly describes how and why analytical methods for styrene in air, for its main metabolites in urine (mandelic and phenylglyoxylic acids) and for critical biological function tests were either chosen from the literature or adapted or developed to fit our criteria of convenience and reliability. In a second step of the preparation of field studies, experimental exposures to styrene were carried out on volunteers so that the best indicators of exposure could be determined and data could be obtained on the elimination kinetics of the urinary metabolites and the quantitative relationships between exposure and the urinary concentrations of mandelic and phenylglyoxylic acids. Finally field investigations, including air and biological monitoring, complete industrial hygiene surveys and medical examinations, have been organized and are being carried out in the Swiss polyester industry. Preliminary results concerning biological monitoring are given.

Air Pollutants↗
PubMed1978

Acute biotoxic effect of styrene on rat liver. Correlation with enzyme-mediated mutagenicity of benzpyrene and acrylonitrile.

Styrene is commonly used in western Europe for the manufacture of plastics suitable for packaging foodstuffs. This report demonstrates that, injected intraperitoneally at a dose as low as 10 mg/kg, styrene modifies the catalytic properties of aryl hydrocarbon hydroxylase by reducing its KM value. A similar effect is reported for two potent chemical carcinogens, 3-methylcholanthrene and benzo(a)pyrene. Ethylbenzene and benzo(e)pyrene and phenobarbital do not produce the same effect. Pretreatments of the rats with chemicals which modify aryl hydrocarbon hydroxylase also increase the capacity of the liver enzymes to activate benzopyrene to a mutagenic intermediate in vitro, as measured by the Ames test for mutagenicity. Exposure to both styrene and the other modifiers of the xenobiotic-metabolizing enzymes could thus influence the carcinogenic and toxic effects of chemicals which are activated by these enzymes. This hypothesis needs further investigation.

Animals↗
PubMed1978

Neurotoxicity of styrene in occupational and experimental exposure.

Occupational styrene exposure caused an increased frequency of abnormal electroencephalograms which correlated to degree of exposure. No dose-response relationship could be shown concerning a slowing of nerve conduction velocities in workers exposed to styrene. Experimental exposure of rats to 300 ppm of styrene caused a transient increase in the nerve conduction velocity in 6 weeks, but in a comparison to control rats no difference was found in measurements performed on rats exposed for 8 and 11 weeks.

Animals↗
PubMed1978

Morbidity among persons employed in styrene production, polymerization and processing plants.

BASF has been producing styrene and polystyrene since 1931. An investigation of morbidity was undertaken for 84 workers employed in the styrene plant and exposed for 1--36 years and 93 workers employed in the polystyrene plant and exposed for 1--38 years. In all groups the concentration of styrene in the atmosphere was measured at various points of the workplace. All workers underwent a thorough physical examination and also extensive laboratory tests, including the determination of urinary mandelic acid. The absenteeism and accident rates were also taken into consideration in both plants. Blood samples were also taken and mandelic acid tests made on a small group of 16 persons employed in polyester processing plants not attached to the BASF.

Absenteeism↗
PubMed1978

Mutagenicity study of workers employed in the styrene and polystyrene processing and manufacturing industry.

Mutagenicity studies were undertaken on lymphocytes from the following groups of persons exposed to styrene or polystyrene: one group from a styrene manufacturing plant, one from a polystyrene plant, and three from plants processing unsaturated polyester resins with different manufacturing methods. For all the groups the concentration of styrene in the atmosphere of the workplace was measured at various points and the amount of urinary mandelic acid was determined. In each case 100 metaphases were analyzed for chromosomal aberrations. The results were compared with reference groups.

Adult↗
PubMedDate not supplied

[A new environmental pathology: styrene-induced rhinitis].

We describe the case of a 36 ys aged woman complaining of symptoms of oculorhinitis with itching, occasional dyspnea and laryngeal constriction. The patient related her symptoms with the emission of dusts and steam from a factory in the neighbourhood producing manufactures using polyester resins dissolved in styrene. No bronchospastic response was obtained after challenge with methacoline and ultrasonic nebulization of distilled water, which instead provoked a significant increase of nasal resistance. The inhalation challenge with styrene produced a dual nasal response. To our knowledge this is the first case of non occupational neighbourhood rhinitis provoked by styrene.

Adult↗
PubMed1996

[Mental health deterioration in workers exposed to styrene].

Emotional instability which might be an early symptom of more severe disorders, is one of the first manifestations of chronic exposure to organic solvents. The present study measures the association between exposure to styrene and mood states of active workers. A total of 128 workers (85% of the total population) from 3 factories where styrene is used, participated on a voluntary basis. They filled out the following self-administered questionnaires: Profile of Mood States (POMS), Psychiatric Symptom Index and Well-being Index. The results indicate a significant relationship between post work-shift urinary mandelic acid (biological indicator of styrene exposure) and the scores obtained on the POMS scales of tension-anxiety (Spearman's rank correlation rho = 0.30; p < 0.01), anger-hostility (rho = 0.29; p < 0.01), fatigue-inertie (rho = 0.34; p < 0.01), and confusion-bewilderment (rho = 0.23; p = 0.04), as well as the Psychological Distress Index (rho = 0.30; p < 0.01). All scores were adjusted for the effects of 4 potentially confounding variables: age, schooling, alcohol and cigarette consumption. These indicators of mood states do not constitute a diagnosis of mental disease but reveal progressive deterioration of well being associated with neurotoxic exposure in the workplace.

Adult↗
PubMedDate not supplied

Toxicity of the styrene metabolite, phenylglyoxylic acid, in rats after three months' oral dosing.

Male Wistar rats were dosed with 0, 1250, 3750 or 5000 mg/l of phenylglyoxylic acid (PGA) (CAS no. 611-73-4) in the drinking water ad libitum for 3 months. During the entire treatment period, there were no gross signs of toxicity related to PGA. No changes in neurobehavior were found after using a functional observational battery or radial arm maze. An increased relative kidney weight was seen in the highest dose-group (Controls: 0.504 +/- 0.031 g/100 g b.wt.; 5000 mg PGA/l: 0.579 +/- 0.033 g/100 g b.wt.; p<0.01). No other organ weights were affected. Histopathology revealed no change in kidney structure. No changes in clinical biochemistry. In the highest dose-group three animals out of ten showed reduction in peripheral nerve myelin sheath thickness. No such changes were seen in the control group. The study revealed no changes in auditory brain stem response but minor changes in electroretinography. The noradrenaline (NA) concentration decreased in pons and thalamus whereas it increased in medulla oblongata and whole brain. The dopamine (DA) concentration increased in cerebellum, hippocampus, pons, and whole brain. The most marked DA increase was seen in hippocampus (Controls: 0.56 +/- 0.10 nmol/g tissue; 5000 mg/l: 1.04 +/- 0.11 nmol/g tissue; p<0.001). The 5-hydroxytryptamine (5-HT) concentration decreased in cerebellum, cerebral cortex, hippocampus, and medulla oblongata, whereas it increased in thalamus. The yield of synaptosomal protein, synaptosomal NA, DA, and 5-HT concentrations, and DA uptake rate were not affected. When dosed males were mated with naive females, there were no differences between groups in the pregnancy rate, number of corpora luteae, implantations, live or dead fetuses, resorptions, preimplantation loss, or postimplantation loss. It is concluded that a part of the effects on kidney, peripheral nerves, and vision, which have previously been reported after exposure to styrene, might be induced by the styrene metabolite, PGA. If PGA has ototoxic effects in rats, the dosing in the present study is not sufficient to induce the necessary ototoxic concentration in blood. Alternatively, the ototoxicity of styrene, like toluene, may be caused the parent compound itself and not by a metabolite like PGA.

Animals↗
PubMed1998

Influence of GSTT1 genotype on sister chromatid exchange induction by styrene-7,8-oxide in cultured human lymphocytes.

The genetic polymorphisms of glutathione S-transferases (GSTs), which are involved in the metabolic inactivation of various toxicants, have been suggested to be an important source of variation in individual response to genotoxic carcinogens. We have previously shown that donor GSTM1 genotype does not influence the induction of sister chromatid exchanges (SCEs) in cultured human lymphocytes by styrene-7,8-oxide (SO), a metabolite of styrene. Here, we expanded the study to GSTT1 polymorphism. SCEs were analyzed from 72-hr whole-blood lymphocyte cultures of five GSTT1 positive (at least one undeleted allele) and five GSTT1 null (gene homozygously deleted) donors, all GSTM1 positive, after a 48-hr treatment with 50 microM and 150 microM SO. SO clearly increased SCEs in cultures of all donors. The mean number of SCEs/cell induced by SO (individual mean SCEs from acetone-treated control cultures subtracted) was 1.7 (50 microM) and 1.4 (150 microM) times greater among the GSTT1 null individuals (4.83 at 50 microM, 18.98 at 150 microM) compared with the GSTT1 positive individuals (2.78 at 50 microM, 13.74 at 150 microM), the differences being statistically significant (P=0.006 and P=0.022, respectively). These findings show that the lack of the GSTT1 gene increases the genotoxic effects of SO in human whole-blood lymphocyte cultures, suggesting that GSTT1 is involved in the detoxification of SO in humans. Although glutathione conjugation is considered a minor metabolic pathway for SO in vivo, the high GSTT1 activity in erythrocytes may be important locally and might affect the level of genotoxic damage observed in peripheral lymphocytes of styrene-exposed reinforced plastics workers. The GSTT1 polymorphism could also influence the urinary excretion of SO-specific mercapturic acids.

Adult↗
PubMed2006

Novel anti-Markovnikov regioselectivity in the Wacker reaction of styrenes.

The Wacker reaction is one of the longest known palladium-catalysed organic transformations, and in the vast majority of cases proceeds with Markovnikov regioselectivity. Palladium(II)-mediated oxidation of styrenes was examined and in the absence of reoxidants was found to proceed in an anti-Markovnikov sense, giving aldehydes. Studies on the mechanism of this unusual transformation were carried out, and indicate the possible involvement of a eta(4)-palladium-styrene complex. With a heteropolyacid as the terminal oxidant, oxidation of styrene to give the anti-Markovnikov aldehyde as the major product was found to be catalytic.

Journal Article↗
PubMed2005

Poly(styrene)-supported co-salen complexes as efficient recyclable catalysts for the hydrolytic kinetic resolution of epichlorohydrin.

Here we describe an unprecedented synthetic approach to poly(styrene)-supported chiral salen ligands by the free radical polymerization of an unsymmetrical styryl-substituted salen monomer (H2salen = bis(salicylidene)ethylenediamine). The new method allows for the attachment of salen moieties to the polymer main chain in a flexible, pendant fashion, avoiding grafting reactions that often introduce ill-defined species on the polymers. Moreover, the loading of the salen is controlled by the copolymerization of the styryl-substituted salen monomer with styrene in different ratios. The polymeric salen ligands are metallated with cobalt(II) acetate to afford the corresponding supported Co-salen complexes, which are used in the hydrolytic kinetic resolution of racemic epichlorohydrin, exhibiting high reactivity and enantioselectivity. Remarkably, the copolymer-supported Co-salen complexes showed a better catalytic performance (>99 % ee, 54 % conversion, one hour) in comparison to the homopolymeric analogues and the small molecule Co-salen complex. The soluble poly(styrene)-supported catalysts were recovered by precipitation after the catalytic reactions and were recycled three times to afford almost identical enantiomeric excesses as the first run, with slightly reduced reaction rates.

Acetates↗