Biomedical subjects

D Mergler

Publications and source records attributed to D Mergler.

14 recordsLinked to original sources

PubMed1992

Stability of psychological impairment: two year follow-up of former microelectronics workers' affective and personality disturbance.

For the past twenty years women's complaints in the microelectronics industry have often been diagnosed as mass psychogenic illness, despite evidence of potential exposure to organic solvents, which have been associated with affect and mood changes. In the present study, the standard version of the Minnesota Multiphasic Personality Inventory (MMPI) was used to evaluate affective and personality disturbance among 63 former microelectronics workers (56 women and 7 men) over a two-year period of time. In both 1986 and 1988, the former workers obtained mean scale score elevations beyond two standard deviations above the normative sample (T = greater than 70) on the MMPI clinical scales of schizophrenia, hypochondriasis, psychasthenia, depression and hysteria. For most scales, 86-88 mean score differences did not attain the 0.05 significance level (two-tailed paired t-test) and no significant differences were observed for 86-88 comparison scale scores = greater than 70 (McNemar paired statistic). Although there were too few men to perform gender comparisons, men scored higher than women on 5 scales and all of the men had scores = greater than 70 on hypochondriasis, depression, hysteria, psychasthenia and schizophrenia. These findings reveal that these former microelectronics workers manifested affective and personality disturbances, consistent with organic solvent toxicity, which persisted over a two year period, indicating that they were not reactive, transient hysterical neurosis.

Adult↗

PubMed1992

Olfactory threshold shift following controlled 7-hour exposure to toluene and/or xylene.

The present study was undertaken to examine olfactory perception threshold (OPT) shift following exposure of healthy subjects to toluene and/or xylene in an inhalation chamber. Five volunteers were exposed to 50 ppm toluene, 40 ppm xylene or an additive mixture of the two, for a period of 7 consecutive hr in an inhalation chamber. A Latin square design was used and subjects were exposed over 3 consecutive days/week, with an 11-day interval between each 3-day session. Olfactory perception thresholds, measured in decismels (ds), were ascertained for both toluene and PM-carbinol, contained in 100 ml bottles with serially increasing concentrations (Olfacto-Lab Kits # 191 & 11). Test administration was based on the forced choice method. Analysis of variance of pre-exposure OPTs indicated that for both toluene and PM-carbinol, significant differences were observed between individuals (p less than 0.05), but not between days or weeks. Measurements, made immediately following exposures revealed a significant six-fold increase in OPT for toluene (median: 15 ds), while PM-carbinol OPT remained stable. Individual differences were observed, but there was no effect of type of exposure, day, week, or interactions. OPT for toluene, determined at intervals following cessation of exposure, indicated a return to pre-exposure values at a mean rate of 6.8 ds/hr. The findings of this study suggest that there is a substantial olfactory threshold shift during a 7-hr period, specific to a particular solvent or family of solvents. Receptor-specific saturation is proposed as the underlying mechanism.

Administration, Inhalation↗

PubMed1991

Affective and personality disturbances among female former microelectronics workers.

The production and manufacture of microelectronic components, carried out primarily by women workers, require extensive use of organic solvents. Affective and personality disturbances frequently have been associated with organic solvent toxicity. A group of women, former microelectronics workers (N = 70), primarily of Hispanic origin (77.1%) but raised in the United States, were evaluated for affective and personality disturbance with the MMPI. Profiles were analyzed, and diagnostic classification was performed blind. Results showed that (1) 85.7% of the profiles indicated abnormally high clinical elevations; and (2) MMPI profile classification revealed four clinical diagnostic groups: somatoform (24.3%), depression (15.7%), anxiety (28.6%), and psychotic (14.3%). These findings indicate significant psychopathology among these women, who formerly had worked in a microelectronics plant. The patterns of impairment present similarities to previous reports of organic solvent toxicity.

Adult↗

PubMed1991

Measurement precision of an olfactory perception threshold test for use in field studies.

Changes in olfactory function have been associated with workplace exposure to a variety of substances. In the workplace, smell can be particularly important, since it is commonly used to detect potentially hazardous situations or as an indicator of mask cartridge breakthrough. Sensitive quantitative measures of olfactory loss would be useful in epidemiological studies and workplace surveillance. The objective of the present study was to determine the reproducibility of an olfactory perception threshold test and variations with age, gender, and smoking status. The test was a standard olfactory kit (Olfactolab No. 11), including 18 serial dilutions of PM-carbinol, with an equal number of blanks. The forced choice method was used, with both tester and subject blinded as to which bottle contained the odorant. Olfactory perception threshold was recorded when the subject identified the same dilution three times. To assess reproducibility, testing was repeated four times over a period of 4 weeks, on the same weekday and the same time of day. Subjects (n = 63) ranged in age from 20 to 60 years (mean age: 39.7 +/- 12.5 years), 47.6% were women, 29.5% currently smoked, and 27.9% were former smokers. Results showed no inter-week differences in olfactory perception threshold (Analysis of variance for repeated measures: F = 0.59; p much greater than 0.05). Inter-class correlation for assessment of agreement of continuous variables was 0.76. Inter-week concordance of hyposmia showed fair to good agreement (0.55 greater than or equal to kappa less than or equal to 0.66). Three-way analysis of variance (ANOVA) revealed significant differences with respect to age category (F = 7.36; p less than 0.001) and current smoking status (F = 4.54; p less than 0.05), but not for gender (F = 2.32; p greater than 0.05). The multiple regression model with age and smoking as independent variables was highly significant (F = 13.03; p less than 0.001), explaining 28% of the variance; olfactory threshold increased 0.47 ds/year (t = 4.01; p less than 0.001) and 0.27 ds/cigarettes/day (t = 2.46; p less than 0.05). The findings of this study indicate that this test is reproducible and sensitive to expected changes with age and smoking status. It corresponds well to criteria for testing in the field and should be considered for studies characterizing olfactory functions and sensory loss among working populations.

Adult↗

PubMed1991

Contrast-sensitivity loss in a group of former microelectronics workers with normal visual acuity.

The measurement of contrast sensitivity at varying grating frequencies is used increasingly to study visual and neural disorders. It provides more information than conventional acuity measures. Refractive errors initially affect high spatial frequencies, whereas lower spatial frequencies are affected only when these errors are pronounced. Neurophysiological alterations are reflected by depressed sensitivity to coarse gratings. Visual dysfunction has been associated with workplace exposures to a wide range of organic solvents. In microelectronics assembly where large quantities of organic solvents are used in many aspects of the work processes, visual deficits have been observed. The objective of the present study was to compare contrast sensitivity among former microelectronics assembly workers, with normal far and near visual acuity, and a reference group from the same region, with similar acuity. No significant differences were observed between scores at the two ends of the contrast sensitivity curves; however, at the intermediate spatial frequencies, the former microelectronics workers' scores were significantly lower (Student's t-test; p less than 0.05). For the microelectronics workers, no relation was observed between age and contrast sensitivity at any spatial frequency, whereas for the reference group, contrast sensitivity scores were progressively lower with age at spatial frequencies greater than or equal to 6.0 cpd (r2 = 0.15 at 6 cpd to r2 = 0.45 at 18.0 cpd), suggesting that for the former there is some form of interference with the expected contrast sensitivity loss with age. Lower contrast sensitivity scores in intermediate spatial frequencies, observed among the former microelectronics workers, possibly reflect neural alterations, which may have resulted from exposure to neurotoxic substances. These findings suggest the need for further studies on visual functions in microelectronics workers.

Adult↗

PubMed1991

Neuropsychological impairment among former microelectronics workers.

Although chemicals posing potential neurotoxic hazards are commonly used in the microelectronics industry, there has been no systematic study of possible chronic nervous system effects in microelectronics workers. The objective of the present study was to assess neuropsychological functions of a group of former microelectronics plant assembly workers and a group of referents, using a matched pair design. During employment, the former microelectronics workers had been exposed to multiple organic solvents, including trichloroethylene, xylene, chlorofluorocarbons and trichloroethane. Referents were recruited from the same geographic region. From a pool of 180 former workers and 157 referents, 67 pairs were matched on the basis of age, sex, ethnicity, educational level, sex and number of children. Comparison of results on the subtests of the California Neuropsychological Screening Battery-Revised (CNS-R) revealed significantly lower performance by the former microelectronics workers on tests of attention/concentration, verbal ability, memory functions, visuospatial functions, visuomotor speed, cognitive flexibility, psychomotor speed, and reaction time (t-test for pairs or Wilcoxon Signed Rank p less than 0.05). No significant differences were observed for performance on tests assessing mental status, visual recall, tactile function and learning. This overall pattern of impairment is consistent with organic solvent-related chronic toxic encephalopathy, and possible early stages of dementia. These findings underline the need for more studies among workers currently or previously employed in microelectronics industries.

Adult↗

PubMed1990

Measurement precision of a portable instrument to assess vibrotactile perception threshold.

The objective of the present study was to evaluate the reliability of a modified version of the commercially available Biothesiometer, and to examine vibrotactile perception thresholds with respect to age and gender. A standardized protocol for measuring vibrotactile perception threshold was administered to 80 subjects, once a week over 4 weeks. Inter-session variability was stable (analysis of variance for repeated measures; P greater than 0.05) and correlations were high (Pearson's: 0.87 less than or equal to r less than or equal to 0.90; P less than or equal to 0.001). For sites on both hands and feet, there was a significant increase with age (0.19 less than or equal to r2 less than or equal to 0.52; P less than or equal to 0.001). Five factor analysis of variance model showed that vibrotactile perception threshold was significantly different with stimulus site, age category and gender; no differences were observed with alcohol consumption or smoking status. The findings indicate that the measurements from this device are highly reproducible and sensitive to expected threshold differences with age and gender. The authors attribute this to technical improvements of the original apparatus, rigid adherence to test protocol and maintenance of standard conditions. This type of instrument would be useful in assessing vibrotactile perception loss in occupational health studies.

Adult↗

PubMed1990

Evidence for adverse reproductive outcomes among women microelectronic assembly workers.

Microelectronics assembly entails complex processes where several potentially fetotoxic chemical compounds are used extensively. This study was undertaken to assess the potential adverse reproductive outcomes among former women workers in a microelectronics assembly plant in New Mexico with respect to a comparable population from the same geographical region and to examine the relation between these outcomes and employment history in this plant. After matching a pool of 143 former microelectronic female workers and 105 referents, 90 former microelectronic female worker-referent pairs were constituted (representing 302 and 324 pregnancies in former workers and referents respectively). The odds ratio (for pair matching design) of spontaneous abortion among women workers, before beginning to assemble microelectronic components, was 0.9 (chi 2 = 0.04; NS). After the beginning of employment this odds ratio became 5.6 (chi 2 = 9.8; p less than 1%). This estimated odds ratio decreased to 4.0, taking into account the increased risk for spontaneous abortion in previous pregnancies before employment (chi 2 = 5.4; p less than 5%). It was not possible to determine if this effect was reversible owing to the small number of pairs available after employment. The findings of this study corroborate the results of former studies that suggest a potential association between electronic manufacturing activity and risk of spontaneous abortion. Although the organic solvents were suspected of being the potential risk factor, this study was inconclusive from this point of view. Nevertheless, these investigations may provide some insight into reproductive outcomes among female workers exposed to solvents.

Abortion, Incomplete↗

PubMed1990

[Go take care of yourself, your factory is sick: the place of mass hysteria in the problem of women's health at work].

Mass hysteria is defined as the epidemic occurrence of a series of physical symptoms in the absence of organic disorder and identifiable pathogen agents. In spite of substantial individual and contextual variations, there are striking similarities that unite the different episodes reported in the literature: existence of a triggering event, progression and rapid regression of unrelated symptoms, and cases involving predominantly women. The authors summarize research in that field and discuss the overrepresentation of women through hypotheses linked with: 1) biology and the weight of differential socialization of women and men; 2) the poor evaluation of environmental, organizational and ergonomical risks in areas where mass hysteria is witnessed. Feminist interpretation tacitly confronts the preconcept notion of feminine vulnerability in order to shed light on the fact that women's adverse working conditions are indeed underestimated.

Female↗

PubMed1989

Cardiac strain among women workers in an industrial laundry.

Occupational heat exposure standards define permissible thermal conditions on the basis of metabolic heat production. However, even when energy expenditure is low, upright posture and repetitive upper limb motion may influence thermoregulatory behaviour through increased cardiovascular stress. The present study was undertaken to examine the relationship between work activity, thermal exposure and cardiac strain among women laundry workers engaged in sedentary, repetitive work activity. Ambient temperatures, work activity and heart rate were recorded during complete work shifts for 11 women over three days in summer and three days in winter. Workstation temperatures were significantly higher in summer. Analysis of continuous recordings of heart rate with respect to work activity showed (i) parallel increases in pulse rate and dominant arm movement frequency; (ii) different patterns of heart rate fluctuations for the two work cycles, with peaks during particular sub-tasks and when arms were in elevated positions. Recommended limits for cardiac strain indices were surpassed in both seasons, although in summer they were exceeded significantly more frequently. The part of cardiac effort attributable to thermoregulatory adjustments was also higher in summer while the fraction reflecting metabolic needs did not change with the season. These findings demonstrate high levels of cardiac strain in this work situation and raise the question of redefining heat exposure standards to include the prevention of excessive cardiac strain resulting from cumulative effects of heat load and ergonomic stressors.

Adult↗

PubMed1988

Chromal focus of acquired chromatic discrimination loss and solvent exposure among printshop workers.

Acquired dyschromatopsia has been associated with exposure to organic solvents. However, the chromal focus of the loss may be indicative of its gravity. According to Kollner's rule, blue-yellow loss reflects changes in external retinal layers, while red-green loss appears to be indicative of internal retinal or optic nerve damage. The objective of the present study was to examine chromatic discrimination capacity of 30 printshop workers exposed to organic solvent mixtures, and of a non-exposed reference group. Colour vision was assessed with a colour arrangement test designed to detect acquired dyschromatopsia, the Lanthony D-15 desaturated panel. Quantitative analysis, using Bowman's colour confusion index, revealed significantly higher scores indicative of colour vision loss among the exposed workers as compared to the non-exposed. Analysis of covariance, with age as co-variate, showed colour confusion index to be significantly associated with job category. Similarly, qualitative analysis showed that the exposed workers presented a significantly higher prevalence of acquired dyschromatopsia as compared to the non-exposed group. However, analysis of the type of chromatic discrimination loss showed that among the nonexposed persons, dyschromatopsia was localized only in the blue-yellow range, while for 35% of the dyschromatopic-exposed persons, red-green loss as well as blue-yellow loss were present. Three-dimensional chi 2-analysis showed that the complex pattern of dyschromatopsia was not related to age, but to job category. These findings suggest that the type of dyschromatopsia, reflecting the gravity of neural alterations, may be a function of exposure level and/or the ophthalmotoxic properties of the particular solvents used.

Adult↗

PubMedDate not supplied

Colour vision impairment and alcohol consumption.

The relationship between alcohol intake and colour discrimination capacity was examined among 136 persons of whom 16 were undergoing treatment in a detoxification centre. Current weekly alcohol consumption (or prior to treatment for those in the centre) was obtained with a detailed questionnaire, which divided week and weekend drinking into types of alcohol (beer, wine, spirits). Alcohol consumption varied from 0-5824 g/week; median: 266 g/week. Qualitative and quantitative assessment of acquired dyschromatopsia was obtained with a colour arrangement test, the Lanthony D-15 desaturated panel. In all age categories, the prevalence of dyschromatopsia increased with alcohol intake. Moreover, all the heavy drinkers (greater than 751 g/week) presented a certain degree of dyschromatopsia, whether or not they were undergoing treatment for alcoholism in a detoxification centre. Colour loss was primarily in the blue-yellow range; however, 4 of the 16 persons from the detoxification centre presented complex dyschromatopsia patterns including red-green loss. This raises the question of possible progressive deterioration. Multiple regression analysis showed that colour vision loss was significantly related to both age (p less than 0.001) and alcohol intake (p less than 0.01). These results underline the importance of taking into account the contribution of alcohol consumption in studies on acquired dyschromatopsia.

Adult↗

PubMedDate not supplied

Colour vision loss among disabled workers with neuropsychological impairment.

Test performance on a neurobehavioural battery was examined with respect to acquired colour vision loss among patients with a history of neurotoxin exposure. The study group included 14 men and 7 women with clinically diagnosed neuropsychological impairment (mean age: 41.3 +/- 8.1 years; mean educational level: 13.4 +/- 1.4 years). Verbal and visual ability, memory and psychomotor function were assessed with the California Neuropsychological Screening Battery. Colour vision was assessed with the Lanthony D-15 desaturated colour arrangement panel. Acquired dyschromatopsia was present in 17 patients (80.9%), 11 of whom manifested patterns of Type II colour vision loss. Simple regression analysis of neuropsychological test performance with respect to colour vision loss, using age-adjusted Z-scores, revealed significant relationships (p less than or equal to 0.05) solely for tests which rely heavily on the visual system. Significant differences in visual task test scores were also observed with the type of dyschromatopsia (Kruskal-Wallis, p less than or equal to 0.05). These findings suggest that poor performance on visual tasks and colour vision loss may both result from damage to neuro-ophthalmic pathways or that loss of integrity of the peripheral visual pathways may affect visual task performance. The authors propose that visual testing should be incorporated into neurobehavioural test batteries.

Adult↗

PubMedDate not supplied

Visual dysfunction among former microelectronics assembly workers.

Although known neurotoxins with potential ophthalmotoxic properties are commonly used in microelectronics assembly, there has been no systematic study of visual disturbances among past or present workers in this industry. The objective of the present study was to compare visual functions, using a matched-pair design, between former workers from a microelectronics plant and a local reference population. From an initial population of 180 former workers and 157 potential referents, 54 pairs were matched for age (+/- 3 y), education (+/- 2 y), sex, ethnic origin, and number of children. Near and far visual acuity, chromatic discrimination, and near contrast sensitivity were assessed monocularly. Paired comparisons (Signed-rank Wilcoxon test) revealed that the former microelectronics workers had significantly lower contrast sensitivity, particularly in the intermediate frequencies, independently of near visual acuity loss. There were no differences for far visual acuity in both eyes. Even though near visual acuity and color vision were compromised among the former workers, the differences were only significant for one eye, as was the prevalence of acquired dyschromatopsia (chi-square for matched pairs, p less than .001). These findings suggest a pattern of contrast sensitivity deficits consistent with impairment to foveal and/or neuro-optic pathways among these former microelectronics workers. Exposure to ophthalmotoxic chemicals is proposed as the most probable risk factor.

Adult↗