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Gas-liquid chromatographic headspace method for vinyl chloride in vinegars and alcoholic beverages.

Vinyl chloride (VC) is determined in vinegars and alcoholic beverages by gas-liquid chromatographic headspace analysis. The lower limit of detection is 10 ppb and confirmation by gas chromatography-mass spectrometry, single ion monitoring at m/e 62, is possible at this level. Comparison of the headspace and the direct injection methods for the determination of VC in vinegars and alcoholic beverages showed that the results obtained by the 2 methods were not significantly different (P greater than 0.05).

Acetates↗

Occupational acroosteolysis in vinyl chloride workers in Israel.

Exposure to vinyl chloride monomer (VCM) may result in a bizarre syndrome, which is characterized by lytic changes in the distal phalanges, cutaneous stigmata of scleroderma, and Raynaud's phenomenon. Detailed case histories of two such patients are presented. Epidemiologic, pathogenetic and radiological aspects of occupational acroosteolysis are briefly reviewed. The possibility is emphasized that the condition may result not only from industrial (i.e., occupational) exposure to VCM but also from exposure in the home or neighborhood (i.e., nonoccupational).

Adult↗

Studies on metabolic activation of vinyl chloride in Drosophila melanogaster after pretreatment with phenobarbital and polychlorinated biphenyls.

It is known that vinyl chloride is metabolized by the mixed function oxygenase system in the liver to reactive mutagenic and carcinogenic metabolites. This metabolic activation was studied in Drosophila melanogaster by measuring the uptake of 14C from labelled vinyl chloride in different strains and with different pretreatments with phenobarbital and polychlorinated biphenyl (PCB) Clophen A50), well known inducers of cytochrome P-450. In accordance with previously obtained data on vinyl chloride induced sex linked recessive lethals, it was shown that pretreatment with inducers increased the uptake of labelled compound up to ten times. There was, however, a marked difference in response between the five strains used. In particular, the strain Hikone, known to be resistant to insecticides, had a comparatively high initial radioactivity from vinyl chloride without any pretreatment, but it was not or insignificantly inducible with phenobarbital or PCB. Crosses between Hikone and an inducible strain indicated essentially a dominance for the Hikone genotype. Tests on inducible strains showed the same response to phenobarbital by 2 h old larvae and adult male and females. Dimethylsulphoxide (DMSO) used as a solvent decreased both the initial uptake of 14C and particularly the induction by PCB. The use of Tween 80 as an emulsifier did not have such an effect. It is emphasized that the interstrain variation in metabolic activation and inducability has to be taken into consideration in order to optimize the use of Drosophila for mutagenicity testing. This variation also opens up new possibilities of analyzing the mixed function oxygenase system biochemically and genetically.

Animals↗

Early detection and signs of hepatoangiosarcoma among vinyl chloride workers.

Health examinations of 108 workers exposed to vinyl chloride monomer (VCM) at a Japanese chemical plant were carried out in 1979. The polymerization of vinyl chloride was started at the plant in 1949. In this study, the highest concentration of VCM in autoclaves was determined to be 250 ppm in 1961. However, the workers at the plant had been exposed to higher concentrations of VCM several times before 1960. More recent VCM exposure was considered negligible. Examinations assessed data on age, height, weight, obesity index, sake consumption, VCM exposure concentration, latent period, cumulative exposure, ICG (indocyano green test), serum bilirubin, GOT (glutamic oxaloacetic transaminase), GPT (glutamic pyruvic transaminase), A1-P (alkaline phosphatase), GGT(gamma-glutamyl transpeptidase), ZTT (zinc turbidity test), LDH (lactate dehydrogenase), cholesterol, TTT (thymol turbidity test), A/G (albumin globulin ratio), and thrombocytes. Variation in VCM exposure did not affect tests of pigment excretion from the liver, such as ICG; thrombocytes; and enzyme activity (such as GPT); nor bilirubin or flocculation reaction in serum.

Adult↗

Pharmacokinetics of vinyl chloride in the Rhesus monkey.

The metabolic elimination of vinyl chloride in Rhesus monkeys is a dose-dependent, satruable process, as in rats. Below 200-300 ppm of vinyl chloride (VC) in atmosphere, elimination obeys a first-order law; the clearance rate is much closer to that found in man than the values for rats, mice and gerbils. The maximal velocity of metabolic elimination of VC at high concentrations in Rhesus monkeys is only about half that of rats when related to kg body weight. It s suggested that Rhesus monkeys mimic the quantitative aspects of VC metabolism better than rats or mice.

Animals↗

Plasma p53 protein and anti-p53 antibody expression in vinyl chloride monomer workers in Taiwan.

Vinyl chloride (VC) workers are known to be at risk for development of angiosarcoma of the liver (ASL), a rare tumor. Previously, a study of p53 gene mutations in tumors of VC-exposed workers found that 50% of liver angiosarcomas contained such mutations. Mutant p53 oncoprotein and anti-p53 antibodies can also be found in the sera of ASL patients and VC-exposed workers without cancer. Workers in Taiwan have also been exposed to VC, and some have contracted liver tumors. In this study, we used enzyme-linked immunosorbent assays to detect mutant p53 protein and anti-p53 antibodies in the plasma of VC-exposed workers in Taiwan. Thirty-three of 251 (13.2%) VC-workers tested positive for the p53 overexpression (10% with positive mutant p53 protein and 3.6% with positive anti-p53) in their plasma, but only 2 of 36 controls (5.6%) tested positive (2.8% with positive mutant p53 protein and 2.8% with positive anti-p53). There was a significant association between cumulative VC exposure concentration and positive p53 expression (P = 0.032) among VC workers after we adjusted for age, hepatitis, drinking, and smoking status. In summary, P53 overexpression (mutant p53 protein or anti-p53 antibody) can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma p53 overexpression and VC cumulative exposure concentration.

Adult↗

Plasma Asp13-Ki-ras oncoprotein expression in vinyl chloride monomer workers in Taiwan.

Vinyl chloride (VC) workers are known to be at risk for development of liver angiosarcoma, a rare tumor. Previously, more than 80% of VC workers with liver angiosarcoma have been found to have an Asp-13 c-Ki-ras oncogene mutation, and more than 50% of VC-exposed workers without liver tumors were found to have Asp13-Ki-ras oncoprotein in their plasma. Some workers in Taiwan had also been exposed to VC, and some have contracted liver tumors. In this study, we used enhanced chemiluminescence Western blotting to detect Asp13-p21-Ki-ras in the sera of VC-exposed workers in Taiwan. There were 14 of 113 (12.4%) VC workers positive for the Asp13-Ki-ras oncoprotein in plasma, but 0 of 18 controls were positive. There were 10 of 69 (14.5%) plasma-positives among the more highly exposed (> 1000 ppm-months) workers and 4 of 48 (9.1%) plasma-positives among the lesser exposed (< or = 1000 ppm-months). Compared with the unexposed controls, the odds ratios (and 95% confidence intervals [CI]) for plasma-positivity were 4.11 (95% CI = 0.21, 80.4) in the lower-exposed workers and 6.53 (95% CI = 0.37, 116.9) in the higher-exposed workers, and there was a linear trend between exposure and plasma-positivity (P = 0.073). After adjusting for age and drinking status, the odds ratios (and 95% CIs) were 1.64 (95% CI = 0.17, 15.8), and 2.65 (95% CI = 0.42, 16.8), respectively, and there was a significant linear trend between exposure and plasma-positivity (P = 0.048). In summary, Asp13-Ki-ras oncoprotein can be found in the plasma of VC workers in Taiwan, and a significant dose-response relationship exists between plasma oncoprotein expression and VC exposure.

Adult↗

Retention of vinyl chloride in the human lung.

Experiments with volunteers showed that 42% of an inhaled dose of vinyl chloride is retained in the lungs. This value is independent of the concentration of vinyl chloride in the air. Elimination of vinyl chloride through the lungs is negligible since its concentration in expired air decreases immediately after the cessation of exposure.

Absorption↗

Induction of gene mutations and gene conversions by vinyl chloride metabolites in yeast.

Chloroethylene oxide and 2-chloroacetaldehyde, two metabolites of vinyl chloride, and 2-chloroethanol, a putative metabolic intermediate, were assayed for their genetic activity in the yeasts Schizosaccharomyces pombe and Saccharomyces cerevisiae. Chloroethylene oxide was found to be the most effective in inducing forward mutations in Sch. pombe and gene conversions in S. cerevisiae, increasing the mutation and conversion frequencies 340 and 50 times, respectively, over those of the controls. In either the presence or the absence of mouse liver microsomes, 2-chloroacetaldehyde showed only feeble genetic activity, and 2-chloroethanol was completely inactive in both yeast strains. In contrast to vinyl chloride, 2-chloroacetaldehyde did not induce forward mutations in Sch. pombe inthe host-mediated assay in mice. The results strongly support the hypothesis that chloroethylene oxide is one of the principal mutagenic agents formed from vinyl chloride in the presence of mouse liver enzymes.

Acetaldehyde↗

Laboratory evaluation of stain-length passive dosimeters for monitoring of vinyl chloride and ethylene oxide.

The effects of vapor concentration in the range of 1.2 to 5.1 ppm (vinyl chloride) and 8.3 to 29.1 ppm (ethylene oxide) on the response of new stain-length passive dosimeters were evaluated separately in a dynamic exposure chamber. The vinyl chloride dosimeter was prepared with a permanganate impregnated blend of Chromosorb W and silica gel, while a silica gel-coated plastic strip (TLC plate) impregnated with dichromate was used to detect ethylene oxide. The use of a TLC plate as the inert support allowed us to reduce the amount of reagent loaded per length of tube, thus significantly enhancing in the sensitivity of the unit, which was necessary for accurately detecting ethylene oxide at these low concentrations. At the vinyl chloride exposure of 8 ppm-hrs the length of stain was 0.76 cm and the 95% confidence interval about this point was +/- 1.4 ppm-hrs (18%). For the ethylene oxide dosimeter the length of stain at the exposure of 80 ppm-hrs was 0.90 cm and the 95% confidence interval about this point was +/- 16 ppm-hrs (20%). Although some shortening of the stain was noted at low relative humidity (26%) in the vinyl chloride device, no effect on the dosimeter response was observed over the range of relative humidity of 35 to 96%. The ethylene oxide dosimeter response was not affected by relative humidity in the range of 28 to 90%. The use of a TLC plate as the inert support of the colorimetric reagent has proven to be an excellent means of improving the sensitivity of these stain-length passive dosimeters.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants, Occupational↗

[Usefulness of different methods of air sampling for the evaluation of workers' occupational exposure to vinyl chloride].

In a selected plant, average airborne concentrations of vinyl chloride were estimated by stationary sampling and autoanalyser. In addition, workers' exposure was estimated by means of individual pumps. The analysis of the obtained results gives evidence that estimation of workers' exposure is correct when sampling is done in the breathing-zone. Average concentrations determined by stationary sampling estimate the environment, but provide no information on workers' exposure. The comparison of the obtained results with the hygienic standard is improper, since the hygienic formation on the values of workers' exposure to vinyl chloride was highly differentiated (from 1.8 to 209.5 mg/m3/8 h) and a positive correlation was found between occupational activities and exposure indices.

Air Pollutants↗

The effect of vinyl chloride monomer, chloroethylene oxide and chloracetaldehyde on DNA synthesis in regenerating rat liver.

Vinyl chloride monomer used in the manufacture of polyvinyl chloride is a chemical of increasing industrial importance but has recently been incriminated as a carcinogen, producing a mutagenic effect after being metabolized to active metabolites. The initial effect of vinyl chloride monomer and two of its presumed metabolites, chloracetaldehyde and chloroethylene oxide, on DNA synthesis was investigated in vivo in regenerating rat liver. The established control curve for the DNA synthesis rate after partial hepatectomy demonstrated two waves of synthetic activity at 21 and 30 h. Vinyl chloride, injected intravenously immediately on completion of the operation, depressed the first wave of DNA synthesis by 49.6%. The second peak of DNA synthetic activity was similar to that of the control. Chloracetaldehyde and chloroethylene oxide both produced similar effects on the first wave of DNA synthesis after partial hepatectomy, inhibiting the DNA synthesis rate by approx. 50%. After a regenerating period of 27 h, however, they produced very different effects, chloroethylene oxide raising the control DNA synthesis rate at 30 h by 49% while chloracetaldehyde tended to desynchronize the well-defined second peak of the control. The test compounds have been compared to literature reports of the inhibitory effects of various carcinogens on DNA synthesis.

Acetaldehyde↗

Chromosomal analysis in vinyl chloride exposed workers: comparison of the standard technique with the sister-chromatid exchange technique.

A group of 21 workers occupationally exposed to vinyl chloride and 6 controls were examined for the presence of chromosomal aberrations or sister-chromatid exchanges in their peripheral lymphocytes. These people comprised a second sampling from a group of exposed workers and controls first examined 18 months earlier. The vinyl chloride exposed workers showed levels of chromosomal aberrations elevated above those of the controls, but there was only a slight increase in sister-chromatid exchanges (per cell or per chromosome) and this increase was not statistically significant. Sister-chromatid exchanges (SCEs) were also examined from in vitro cultures of lymphocytes exposed in G0/early G1 and late G1/early S phase to vinyl chloride, both with and without metabolic activation. There was no increase in SCEs in vitro without metabolic activation but there was a marked increase with metabolic activation and this increase was shown to be independent of cell-cycle phase. It thus was apparent that the small increases of SCEs in workers were not due to the inability of vinyl chloride to induce SCEs in human lymphocytes but were probably because of low exposures and SCE levels could have returned to normal relatively quickly after exposure. The present study suggested that the analysis of longer-living conventional chromosomal aberrations appeared to be a more sensitive monitor of exposure to vinyl chloride in exposed workers than the estimation of SCEs; however, it should be noted that in a 3rd sampling taken 24 months later the exposed workers had chromosomal aberration levels similar to the controls.

Cells, Cultured↗

[Determination of vinyl chloride in the air by the gas chromatography method].

The purpose of the paper was to work out a gas chromatographic method for determination of vinyl chloride in the air at work places in the chemical plants. The best results have been obtained at 50 degrees C on 3-meter column containing 10% SE-30 on Chromosorb W AW DMCS, 80--100 mesh. Two methods of sampling have been considered: that of collecting samples in vacuum pipettes and that of adsorption on charcoal. In the former method stability of collected samples has been investigated (Fig. 3). A slight decrease in concentration of the vinyl chloride (approximately 3%) was found in four hours. In the latter method two ways of determination of vinyl chloride desorption coefficient from charcoal have been investigated. Since no essential difference in values of desorption coefficient has been observed, both ways for determination of desorption coefficient may be employed. A modified device for preparation of standard concentrations of vinyl chloride in the air has been utilized in our research (Fig. 2). The relative standard deviation resulting from analysis of samples was +/- 0.075. The minimum determinable amount of vinyl chloride was found to be 10 ng per injection.

Air↗

Headspace sampling and gas-solid chromatographic determination and confirmation of greater than or equal to 1 ppb vinyl chloride residues in polyvinyl chloride food packaging.

The determination and confirmation of residual vinyl chloride (VC) in polyvinyl chloride (PVC) food packaging materials are described. PVC packaging materials are dissolved in dimethylacetamide (DMAC). VC is sparged from solution with helium gas and collected in sealed vials of ethanol. VC is detected and quantitated by using a headspace sampling technique and standard gas-solid chromatography (GSC) with flame ionization detection. GSC peak heights of about 5% full scale deflection are obtained for samples of PVC containing 1 ppb VC. Polymer samples taken from tubing, blood bags, food packaging films, bottles, and unprocessed resin were analyzed. Residual VC levels ranged from 0.3 to 913 ppb. VC was confirmed by GSC-mass spectrometry, using selected ion recording of m/z 62 and 64 in conjunction with full mass scans to identify components eluting near VC.

Chromatography, Gas↗

[Determination of time-weighted average concentration for vinyl chloride in the air of workplace].

OBJECTIVE: To establish a gas chromatographic method with carbon disulfide desorption for time-weighted average (TWA) concentration of vinyl chloride in the air of workplace. METHODS: Vinyl chloride in the air was sampled individually with activated charcoal tube. Vinyl chloride was desorbed by carbon disulfide for 30 minutes and analyzed by GC (FID). Time was used for qualitative analysis and peak area was for quantitative analysis. RESULTS: Linearity range was 0.0264-1.6896 mmol/L and the coefficient of correlation was 0.9999. Limit of detection: 1.2 ng (injection of 1microl). Relative standard deviation that expressed precision ranged from 3.8% to 6.7% for different concentrations. And average desorption efficiency of carbon disulfide was 90.77%. CONCLUSION: These indicators were corresponding to the Chinese guideline of the method for determination of toxic substances in workplace air and confirmed to be suitable for determining TWA concentration of vinyl chloride in workplace.

Air Pollutants, Occupational↗

Changes in pulmonary function in workers exposed to vinyl chloride and polyvinyl chloride.

To determine whether occupational exposure to vinyl chloride gas and polyvinyl chloride dust is associated with changes in pulmonary function, spirometry and maximum expiratory flow-volume curves were obtained in 348 workers in a VC polymerization plant. The major finding was diminution in air flow in 200 workers (57.5 percent). This abnormality correlated with age and duration of exposure. A relationship with smoking was noted only in younger workers with exposures of less than 10 years. When age exceeded 40 years or exposure 20 years, prevalence of this impairment was similar in smokers and nonsmokers, suggesting that occupational or other environmental factors were operative.

Adult↗

[Clinical characteristics of early symptoms caused by chronic exposure to vinyl chloride].

Analysis of clinical signs seen in chronic vinyl chloride intoxication proved that early stages of the disease are characterized by functional neurologic disorders (vegetoneurosis, astheno-neurotic and astheno-vegetative syndromes) and vegetative sensory neuropathy. Periodic medical examinations of workers having continuous contact with vinyl chloride proved that neuropathologist plays major role in diagnosis and indispensably participates in the examination.

Adolescent↗