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PubMed1990

Direct determination of styrene-7,8-oxide in blood by gas chromatography with flame ionization detection.

A simple capillary gas chromatographic method is described for direct determination of styrene-7,8-oxide (styrene oxide) in blood samples of 1 ml, with a detection limit of 1 ng/ml. After the addition of 1-phenylpropylene oxide as internal standard, blood samples were extracted with n-hexane, the n-hexane phases were concentrated under nitrogen, and up to 25 microliters of the resulting solution were injected on-column using a retention gap. Separation was carried out on a fused-silica capillary column coupled to a flame ionization detector. Using this method the metabolism of styrene oxide in rat blood was investigated. Concentrations of styrene oxide in the blood of rats exposed to styrene at atmospheric concentrations between 20 and 800 ppm for 3 h at steady-state conditions are reported.

Animals↗
PubMedDate not supplied

Migration of styrene monomer from thermoset polyester cookware into foods during high temperature applications.

Migration of styrene from thermoset polyester cookware into foods has been studied during normal cooking applications and for the fatty food simulant olive oil under high temperature test conditions. The analysis of foods was by automated headspace gas chromatography/mass spectrometry (GC/MS) in the selected ion mode. Cyclohexane was added to the slurried foods to improve headspace partition and deuterated-styrene was the internal standard. To achieve adequate sensitivity with olive oil, styrene was extracted and concentrated by a steam distillation method and then determined by GC/MS. Styrene in foods cooked in thermoset polyester articles was in the range < 5 to 5 micrograms/kg and 5 to 30 micrograms/kg where the polyester contained 9 and 380 mg/kg residual monomer respectively. Testing for 2 h at 175 degrees C into olive oil resulted in significantly higher migration of styrene than seen for other foods, although there was a marked decrease in migration on repeat-use. Testing of the complete articles as sealed systems filled with olive oil led to higher migration than testing by total immersion of plaques. Of the test methods used with olive oil, testing as filled articles with no lidding gave migration results closest to (but generally higher than) those seen for real foods.

Cooking and Eating Utensils↗
PubMed1992

Lymphohematopoietic cancer in styrene-butadiene polymerization workers.

1,3-Butadiene and styrene are suspected carcinogens and common chemicals used in the synthesis of rubber. To investigate any potential human hazards from exposure to these chemicals, a case-control study of 59 lymphohematopoietic cancers was conducted within a cohort of male workers employed between 1943 and 1982 in eight North American styrene-butadiene rubber polymer-producing plants. A total of 193 controls were matched to the cases by plant, age, year of hire, duration worked, and survival to time of death of the case. Each job was assigned an estimated exposure rank, and each worker's cumulated rank score was calculated on the basis of the time spent in each job throughout his employment. "Exposure" as a dichotomous variable was defined as a log rank score above the mean of the log scores for the total population of cases and controls within a subtype of cancer. Matched-pair analysis identified a strong association between leukemia and butadiene, with an odds ratio of 9.36 (95% confidence interval 2.05-22.9) and an association between styrene and leukemia (odds ratio = 3.13, 95% confidence interval 0.84-11.2) that did not achieve statistical significance. When exposure to both styrene and butadiene was included in a conditional logistic regression model, the odds ratio for butadiene remained high (odds ratio = 7.39), but the estimated association of leukemia with styrene was small. The results of this study support the hypothesis that exposure to butadiene is associated with the risk of leukemia. There also appears to be an additional risk from work in specific subdivisions of the industry.

Butadienes↗
PubMedDate not supplied

Determination of mandelic acid and phenylglyoxylic acid in the urine and its use in monitoring of styrene exposure.

This paper describes a sensitive biological monitoring method for assessing exposure to styrene. Two major metabolites of styrene, mandelic acid (MA) and phenylglyoxylic acid (PGA), were measured in urine using reversed-phase high-performance liquid chromatography with a variable wavelength UV detector. The urine sample (200 microL) was saturated with 60 mg of sodium chloride and spiked with 20 microL of internal standard (O-methyl hippuric acid). Hydrochloric acid (6N HCl) was added for acidification followed by extraction with ethyl acetate. The extract (0.5 mL) was dried and reconstituted with the mobile phase. The mobile phase used was water-methanol (90:10) with 0.5% acetic acid. The filtrate (5 microL) was injected into the HPLC with a C18 column. The detection limits for MA and PGA were estimated to be 5 mg/L and 0.5 mg/L, respectively. The average recovery was 96% for MA and 84% for PGA. The between-days coefficients of variation for both metabolites were generally less than 11%. The average within-day variations were usually less than 5%. The method was verified with urine samples collected from workers exposed to styrene. Excellent correlations were observed between environmental styrene exposure and urinary MA (r = 0.92) and PGA (r = 0.85), determined by using the present method. The procedure is sensitive and reproducible, and can be applied to occupational health measurement of styrene exposure.

Chromatography, High Pressure Liquid↗
PubMed1996

Stereospecific dihydroxylation of the styrene vinyl group by purified naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.

Naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 adds both atoms of the dioxygen molecule to styrene to form (R)-l-phenyl-1,2-ethanediol. Product formation is tightly coupled to dioxygen consumption and NADH oxidation. NDO oxidizes styrene-d8 at almost the same initial rate as styrene. The results indicate that dioxygen activation by NDO is different from that by cytochrome P-450 and other monooxygenases, which oxidize styrene to styrene 1,2-oxide.

Dioxygenases↗
PubMed1985

No acute behavioural effects of exposure to styrene: a safe level of exposure?

To determine whether exposure to low levels of styrene (below 110 mg/m3) causes acute behavioural effects and symptoms that may be related to concentrations of styrene in air or urinary mandelic acid or both, 12 men occupationally exposed to styrene were studied and compared with a reference group of 10 unexposed men. Simple reaction time was measured before and after work and information about symptoms was obtained by questionnaire. Active and passive sampling of airborne styrene was carried out and urinary mandelic acid concentrations were measured. Although the size of the study groups is small, the results indicate that exposure to styrene below 110 mg/m3 does not cause any acute adverse effects on the central nervous system.

Adult↗
PubMed1993

Increase in neuropsychiatric symptoms after occupational exposure to low levels of styrene.

The results of this study suggest that exposure to styrene below the current Swedish permissible exposure limit of 20 ppm induces neurotoxic effects expressed as an increased number of neuropsychiatric symptoms. Twenty men exposed to styrene at a plastics factory participated. The reference group included 20 non-exposed men matched for age, working schedule, and physical work load. Exposure to styrene during one workday was assessed by personal air monitoring and biological monitoring. To evaluate the physical work load the pulse(heart) rate was measured. One week before the study each man completed a neuropsychiatric symptom questionnaire containing 16 items. Also 17 questions regarding acute symptoms of local irritation and symptoms of the central nervous system were presented after the psychometric tests were performed. The tests were simple reaction time, colour word vigilance, and symbol digit. A follow up with regard to the symptoms among the exposed men was done after their summer vacation, about two to five weeks after their last exposure. The mean eight hour time weighted average (TWA) concentration of styrene in air, measured by passive dosimetry was 8.6 ppm (range 0.04-50.4 ppm). The exposed men had significantly more symptoms than the referents although there were no significant differences for the psychometric tests. At the follow up the exposed men reported fewer symptoms. This study indicates that symptoms are earlier indicators of adverse effects than complex tests and underlines the importance of regular follow up of people exposed to styrene (and probably organic solvents in general).

Acute Disease↗
PubMed1995

Exposure to styrene and chronic health effects: mortality and incidence of solid cancers in the Danish reinforced plastics industry.

OBJECTIVES: To study the occurrence of non-malignant diseases and solid cancers in workers exposed to styrene in the Danish reinforced plastics industry. METHODS: All 36,610 workers of 386 reinforced plastics companies and 14,293 workers not exposed to styrene from similar industries were followed up from 1970 to 1990. This industry is characterised by simple exposure conditions, exposure to high concentrations of styrene, and a high proportion of small companies, and the exposure assessment was based on experts' classification on a company level. The mortality from non-malignant causes and the incidence of solid cancers were compared with the national rates. Poisson models were used for internal comparisons. RESULTS: A total of 3031 deaths and 1134 newly diagnosed cases of solid cancer were reported in the workers in the reinforced plastics industry. In companies where 50% or more of the workers produced reinforced plastics an increased mortality rate ratio (MRR) for degenerative disorders of the nervous system (multiple sclerosis, parkinsonism, and motor neurone disease; MRR 1.8, 16 cases, 95% confidence interval (95% CI) 0.9-3.8) and an increased incidence rate ratio (IRR) for pancreatic cancer (IRR 2.2, 17 cases, 95% CI 1.1-4.5) was found. For both disease categories increased occurrence was also found among long term workers, workers of the 1960s (the period with the highest exposure to styrene), and workers with a latent period of more than 10 years after the start of employment. No other non-malignant diseases or solid cancers showed these patterns. CONCLUSION: The findings have to be interpreted with caution, due to the company based exposure assessment, but the possible association between exposures in the reinforced plastics industry, mainly styrene, and degenerative disorders of the nervous system and pancreatic cancer, deserves attention.

Cause of Death↗
PubMed1988

Effects of styrene on wheel-running and ambulatory activities in mice.

Effects of styrene on wheel-running and ambulatory activities were investigated in mice. Sixty male mice (ICR strain) were divided into 10 groups of six mice each, and they were exposed to styrene of about 930, 425, 60, 25 or 0 ppm (control group) for 4 hours a day, 5 days a week over 2 weeks. The wheel-running and ambulatory activity tests were conducted during 2 weeks of the styrene exposure, and 1 week before and after the exposure. The wheel-running activity decreased at the high concentrations (930 and 425 ppm), and the decreased activity did not recover to the control level after cessation of the exposure. In the ambulatory activity test, styrene exposure resulted in the decrease in the activity, though the change was not concentration-dependent. The present results suggest that the behavioral effect of styrene is clearly detectable by means of wheel-running and ambulatory activities in mice.

Administration, Inhalation↗
PubMed1994

Cancer mortality in a historical cohort study of workers exposed to styrene.

OBJECTIVES: The goal of this study was to determine whether exposure to styrene is associated with an increased risk for neoplasms of the lymphatic and hematopoietic tissues. METHODS: A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden, and the United Kingdom. It involved 40,688 workers ever employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories and environmental and biological monitoring data. Cause-specific national death rates were used as the reference. Poisson regression was applied for internal comparisons. RESULTS: Among the exposed workers, no excess was observed for mortality from all neoplasms. Mortality from neoplasms of the lymphatic and hematopoietic tissues increased with time since first exposure and average level of exposure to styrene, but was not consistently associated with duration of exposure or with cumulative exposure. CONCLUSIONS: These findings leave open the possibility of an excess risk of neoplasms of the lymphatic and hematopoietic tissues among workers exposed to styrene.

Cohort Studies↗
PubMed1995

Peripheral neuropathy in styrene-exposed workers.

BACKGROUND: The toxicity of styrene on the peripheral nervous system is still debated. CASES: The paper presents two cases of peripheral sensorimotor neuropathy in styrene-exposed workers. Exposure, evaluated by biological monitoring, ranged between 100 and 150% of the current limits proposed by the American Conference of Governmental Industrial Hygienists (ACGIH). The subjects complained of leg weakness and numbness, cramps, and paresthesia. Electrophysiology revealed a moderate peripheral sensorimotor neuropathy of a demyelinating type. Color-vision testing showed a subclinical deficit. Common inherited and acquired causes of peripheral neuropathy and dyschromatopsia other than styrene were ruled out by personal history, medical examination, laboratory data, and chest X-ray. CONCLUSIONS: The results suggest that long-term occupational exposure to environmental levels of styrene that are equal, or slightly above, the ACGIH limits can induce a clinical form of peripheral neuropathy and a subclinical impairment of color vision. As a consequence, a careful reappraisal of the real preventive meaning of the current ACGIH occupational limit for styrene, at least on an individual basis, is needed.

Adult↗
PubMed1992

[The effect of elevated amounts of ascorbic acid on the status of the vitamin and lung disorders in guinea pigs inhaling styrene].

An inhalation intoxication with styrene is performed on guinea pigs--600 mg.m-3, 5 hrs daily, 5 days weekly for a period of 4 weeks. The animals are put on regime lacking vitamin C. Ascorbic acid is introduced orally on 3 levels: 20 mg.kg-1 body mass (control) and with increased quantities 60 mg.kg-1 and 240 mg.kg-1 body mass. On the third day the content of ascorbic acid in some biochemical parameters of the lung is determined. Histochemical examinations of the lung tissue are made. The styrene causes decrease in the ascorbic acid content in the lung, considerable increase of the studied enzymes (lactate- and glucose-6-phosphate-dehydrogenase, alkaline and acidic phosphatase) and the concentration of the total protein in the lung. There are inflammatory, dystrophic and obturation changes. The raised intake of ascorbic acid 60 mg.kg-1 body mass doesn't effect the negative influence of styrene. The high dose (240 mg.kg-1 body mass) provokes increased activity of the examined enzymes. At inhalation with styrene this dose of ascorbic acid increases the styrene effect on the enzyme activity, especially of LDH and glucose-6-phosphate-dehydrogenase, without invigorating the pathomorphological disturbances in the lung.

Administration, Inhalation↗
PubMed1991

[The effect of occupational exposure to styrene on the metabolism of lipids and lipoproteins].

A total of 53 subjects with working exposure to styrene (1-29 years) has been investigated. On lipid and lipoproteins examination, only 8 persons (15%) showed normal values. The amount of 26 (49%) persons had the increase in HDL-cholesterol values. Subjects with protracted exposure to styrene (11-29 years) had higher level of cholesterol, absolute HDL-cholesterol values, total VLDLs and atherogenic index as compared to those which have worked at risk of styrene for 1-10 years. However, there was no statistically significant difference. Occupationnaly styrene exposed persons had statistically higher HDL-cholesterol (expressed both absolutely and relatively) in comparison with 21 clinically healthy controls. Changes of total cholesterol, VLDLs and of atherogenic index may partly be explained with factor of age. However, this is no such an explanation for HDL-cholesterol, since in adverse to that it decreases with more age in a normal population. Authors assume the pathologically higher HDL-cholesterol levels may exhibit causal interaction with occupational exposure to styrene, probably through the induction of microsomal liver enzymatic systems.

Adolescent↗
PubMed1991

Acquired dyschromatopsia among styrene-exposed workers.

We investigated the occurrence of color vision loss in 75 styrene-exposed workers and in 60 referents. Color vision was evaluated by adopting the Lanthony D 15 desaturated panel, a test specifically suited to detect mild acquired dyschromatopsia. The results of the test were expressed as Color Confusion Index. Styrene exposure was evaluated with both environmental and biological monitoring. Airborne levels of the solvent were 3.2 to 549.5 mg/m3. In styrene-exposed workers color vision was significantly impaired when compared with referents matched for age. A significative correlation was found between environmental and urinary levels of styrene and Color Confusion Index excluding the influence of age in multiple regression analysis, indicating the possibility of a dose-effect relationship. The findings suggest that styrene can induce an early appearance of a dose-dependent color vision loss.

Adult↗
PubMed1988

[Styrene-induced occupational asthma and rhinitis].

Styrene is an aromatic compound widely used in the production of plastic polymers and rubbers. Studies of the effect of styrene on the respiratory tract are scarce. We describe three cases of occupational asthma and one case of occupational rhinitis due to styrene, which have been recently observed in our center. There is evidence that styrene can be a primary cause of occupational asthma and rhinitis. The mechanisms of action are unknown. Our findings suggest the need for preventive strategies for styrene exposed workers.

Adult↗
PubMed1985

Fetal distribution of styrene in rats after vapor phase exposures.

Pregnant rats were subjected to a 5-hour exposure of either 2,000 or 1,000 ppm atmospheres of styrene. Concentrations of styrene in the maternal blood and in each fetus were measured. The fetal concentrations in the 2,000 ppm exposure group were significantly more than double that in the 1,000 ppm group. Fetal weight and distribution of styrene appear to be related to the fetal position on the uterine horn. Those at the ovarian and cervical ends of the uterine horn were of lowest weight and those at the ovarian end had the highest concentration of styrene. Concentrations of styrene appeared to be much lower in the fetuses than in maternal organs and tissues after similar exposures.

Aerosols↗
PubMedDate not supplied

Effect of gestational and neonatal styrene exposure on dopamine receptors.

The effect of styrene (200 mg/kg, orally) on dopamine receptor binding using 3H-spiroperidol as a specific ligand was studied in developing rats. Gestational exposure caused no significant change in the binding of 3H-spiroperidol to striatal membranes of pups at 2 and 3 weeks of age. However, styrene exposure during lactation and the gestation-lactation period caused a significant increase in binding of 3H-spiroperidol. Scatchard analysis revealed that styrene exposure caused an increase in the number of receptor sites without affecting their affinity. Results of behavioral studies (amphetamine-induced locomotor activity and apomorphine-induced stereotypy) showed that styrene exposure during the gestation-lactation period caused a significant increase in motor activity and stereotypy of the rat pups. These behavioral and biochemical studies suggest that early postnatal exposure to styrene affects dopaminergic function.

Amphetamine↗
PubMed1983

Determination of styrene migration from food-contact polymers into margarine, using azeotropic distillation and headspace gas chromatography.

Migration studies were conducted to determine the quantity of styrene that migrates from polymers into fatty foods, specifically margarine. Azeotropic distillation was used to isolate styrene from the margarine. Headspace gas chromatography with a Chromosorb 104 column and a flame ionization detector was used for quantitation. The quantitation limit for the method was about 25 ppb (wt/wt) styrene in margarine. On the average, greater than 90% of the styrene was recovered. Several commercial margarines were examined. The method and results of the migration studies are presented. There was no detectable migration of styrene into margarine.

Chromatography, Gas↗