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.

Mutagenicity of vinyl chloride. External chromosome studies on persons with and without VC illness, and on VC exposed animals.

Chromosome analysis was undertaken on lymphocyte cultures taken from (1) six workers with estimated exposure to VC and four workers with monitored exposure to VC (employed in the BASF); (2) 20 workers showing symptoms of VC illness with unknown exposure and one angiosarcoma case, due to VC exposure (not employed in the BASF); and, (3) on bone marrow cells of Chinese hamsters after inhalation of 2,500 ppm or 5,000 ppm, or after intraperitoneal injections of 300 mg/kg or 600 mg/kg. The proband groups showing symptoms of VC illness, the only living angiosarcoma case, and the animal test show a significant increase in the rate of aberrations in comparison to the control group.

Chromosome investigations on workers exposed to styrene/polystyrene.

Chromosomes investigations were undertaken on 12 employees with three to 34 years possible exposure to styrene in order to determine if there was a possibility of chromosome impairment. The data did not reveal any significant differences between persons exposed to styrene and members of the control group. The concentrations of styrene at the workplace were far below the MAC value and also the mandelic acid content of the urine was far below the norm.

Analysis of chromosomes of workers exposed to acrylonitrile.

Examination of 18 workers who had been exposed to acrylonitrile for 15.3 years on average and 18 workers who had not been exposed to acrylonitrile showed no difference in the incidence of chromosome aberrations; for each person concerned 100 metaphases were evaluated.

Cytogenetic studies in lymphocytes of workers exposed to 2,3,7,8-TCDD.

Chromosome aberrations and sister chromatid exchanges (SCEs) were evaluated in 27 workers with current 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) blood lipid concentrations exceeding 40 parts per trillion (ppt) and in 28 unexposed referents of similar age. No statistical differences were found between the two groups in the percentages of gaps, chromatid or chromosome exchanges, chromatid or chromosome breaks/fragments/deletions, multiple aberrations, or the overall percentage of aberrations including gaps (1.33% in the exposed group vs 1.75% in the referent group) or excluding gaps (0.54% in each group). There was an increased rate of SCEs per cell (P = 0.051) and a higher percentage of cells with more than 10 SCEs (P = 0.064) in the exposed group; however, these associations were no longer significant when smoking status was included as covariate. Additionally, neither current nor back-calculated TCDD concentration was a significant predictor of these parameters based on multiple linear and rank regression analyses.

Chromosome investigations of workers exposed to cadmium in the manufacturing of cadmium stabilizers and pigments.

Chromosome analyses were undertaken on 14 workers exposed to cadmium and the results were compared with a corresponding control group. All probands have been employed for many years in cadmium pigment and stabilizer production plants (between 6 and 25 years). The results of the clinical investigations were, for the most part, unspecific, although at the same time some parameters were above the normal (transaminase, beta 2-microglobulin deposit in the urine, as well as cadmium in the blood and urine). The chromosome analyses were undertaken on the lymphocytes of the peripheral blood with the aid of the so-called "micromethod." Metaphases, 150 per person, were analyzed. The statistical evaluation was made according to the Fisher-Yates test. The chromosome aberration rate of the group investigated was not higher than that of the control group, inclusive and exclusive of gaps.

Mutagenicity study of workers exposed to alkylene oxides (ethylene oxide/propylene oxide) and derivatives.

Employees of plants where alkylene oxide is manufactured or processed were subjected to mutagenicity studies carried out on lymphocyte cultures in accordance with the methods of Moorhead at al, de Jong and Anders. The employees were divided into four groups, according to their periods of exposure: (1) Long-term exposure for more than 20 years; (2) exposure for less than 20 years; (3) long-term exposure and accident (ethylene oxide inhalation or skin contact); and (4) accident, i.e., brief high exposure to ethylene oxide. Measurement of the concentrations in various sections of the plant yielded values of up to 3 ppm under conditions of normal operation. However, this figure rose briefly to 1900 ppm under plant breakdown hat workers were subjected to higher exposure in the past. One hundred metaphases per person were analyzed for chromosome aberrations. The results are given in Tables 1 through 4. A significant increase in the aberration rate was found only in employees in Group 1. This was confirmed by a control examination carried out one year later. The employees of groups 2, 3 and 4 displayed no significant increases. However, in evaluating these findings, it should be noted that the employees had been in contact with a wide range of substances and products in the course of their occupation, which means that the increased aberrations rate found cannot be attributed unequivocally to exposure to a particular substance.