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Biomedical subjects

D C Glass

Publications and source records attributed to D C Glass.

10 recordsLinked to original sources
PubMed1992

Occupational exposure to carbon monoxide and sulphur dioxide during the manufacture of carbon black.

The manufacture of carbon black is known to generate carbon monoxide and sulphur dioxide in the 'production gas' and the pyrolysis products of the 'production gas', respectively. Adverse health effects have been reported as associated with both contaminants (coronary heart disease with carbon monoxide and respiratory morbidity with sulphur dioxide). A major cross-sectional and longitudinal respiratory morbidity study is being conducted to assess the effects of exposure to carbon black on lung function, on chest X-rays and on responses to a questionnaire. The questionnaire includes questions on respiratory and cardiovascular symptoms, so that information regarding confounding exposure is essential. The working population of 18 manufacturing plants in seven European Countries was split into 13 job title numbers (1-13) which were then amalgamated into five job categories (A-E), with an appropriate (statistically) number of samples taken from each plant-job category. In total, 1322 carbon monoxide samples and 1301 sulphur dioxide samples were taken, using actively pumped longterm colorimetric tubes. In the majority of cases, more than half of the samples in each plant-job category were either zero or trace, thereby preventing the accurate estimation of the average exposure. The highest median carbon monoxide concentration was from the amalgamated data from all 18 plants in job number 9 (furnace operators), the highest median sulphur dioxide concentration was only 'trace'. The large number of zero and trace values also precluded the generation of current and retrospective exposure indices.

Air Pollutants, Occupational↗
PubMed1992

Occupational exposure to carbon black in its manufacture.

Carbon black is manufactured by the vapour phase pyrolysis of heavy aromatic hydrocarbon feedstocks. Its manufacture is worldwide and the majority of its production is for use in the rubber industry especially tyre manufacture. Its carbonaceous nature has led many to investigate the occurrence of exposure-related medical conditions. To quantify any such relationships, it is necessary to assess exposure accurately. As part of such an epidemiological investigation survey involving the measurement both of respirable and of total inhalable carbon black was undertaken in 18 plants in seven European countries between mid-1987 and mid-1989. A total of 1298 respirable samples (SIMPEDS cyclone) and 1317 total inhalable samples (IOM head) were taken and deemed of sufficient quality for inclusion in the study. The distributions of the time-weighted average values were assessed and found to be best described by a log-normal distribution, and so exposure is characterized by geometric means and standard deviations. The data are presented in terms of 13 separate job titles for both dust fractions and shows a wide variation between job titles, with the highest mean exposure experienced by the site cleaners, and 30% of the samples taken from the warehouse packers being in excess of the relevant countries' occupational exposure limits for total inhalable dust. The quality and extent of this data allows both for comparison with exposure standards and for generation of occupational exposure indices, which will be presented in another paper (Gardiner et al., in preparation).

Carbon↗
PubMed1991

Effects of emotional imagery on physiological and facial responses in Type A and Type B individuals.

Type A behavior was examined in relation to physiologic and facial-expressive changes associated with anger, fear and distress. Affect was induced by an imagery procedure in which subjects recalled and described actual, emotion-related episodes. Type A was assessed by a structured interview. Subjects were healthy men, 21 Type As and 21 Type Bs, whose mean age was 39 yr. Type Bs showed higher systolic blood pressure responses and greater expression of negative affect than Type As. Data analysis also revealed a tendency for enhanced physiologic and facial responses of Type Bs relative to Type As to be greater during fear and distress than during anger. These results appear to reflect a coping process whereby Type A individuals show attenuated facial-expressive and physiologic reactivity as a means of maintaining a sense of control over aversive conditions.

Adult↗
PubMed1979

Harm-doing and victim's racial or orthopedic stigma as determinants of helping behavior.

Three experiments tested a prediction derived from an ambivalence theory of behavior toward the stigmatized. The prediction was that unintentional harm-doers would be more likely to make restitution by doing a favor for a stigmatized victim than for a nonstigmatized one. In Experiment 1 it was upheld for black versus white victims. In Experiment 2, where the victim of harm-doing was either physically handicapped or normal, the prediction was upheld only among older subjects, following the post hoc introduction of an age variable. Experiment 3 also used a physical disability variable. The data were consistent with the prediction, although the adequacy of the harm-doing manipulation was not checked empirically. On the whole, these results are seen as complementing previous findings of amplified post-harm-doing denigration of black and disabled victims. An assumption that the relationship between harm-doing and altruism was mediated by guilt arousal received only fragmentary support. That is, self-reports of guilt were highest in the harm-doing black confederate condition in Experiment 1, and self-reports of negative affect were highest in the harm-doing/wheelchair confederate condition in Experiment 3, but there were no significant relationships between individual differences in guilt or negative affect on the one hand, and amount of helping, on the other.

Adolescent↗
PubMed1978

When courtesy offends: effects of positive and negative behavior by the pbysically disabled on altruism and anger in normals.

The initial hypothesis was that physically disabled help-seekers will receive more aid from normal people than will help-seekers when both types of actors display positive personal qualities, whereas the reverse outcome will occur when both display negative qualities. In the first experiment a wheelchair-bound or normal confederate was either friendly and achievement oriented (positive condition) or caustic and apathetic (negative condition) while administering verbal tasks to subjects who were later asked to help the confederate. Contrary to prediction, subjects offered more help to the normal than to the disabled tester in the positive condition, and showed the reverse pattern in the negative condition. It was conjectured that subjects in the positive condition were annoyed by the disabled person's display of "normal" characteristics, whereas in the negative condition they sympathetically accepted the disabled person's inadequacies as befitting a victim of severe misfortune. A new experiment was done, which replicated the independent variables of the first study, but substituted two new dependent variables: covert anger arousal and perception of the confederate as happy-unhappy. As expected, covert anger was greater in the wheelchair-positive condition than in the normal-positive condition, and greater in the normal-negative condition than in the wheelchair-negative condition. Regardless of the confederate's physical status, subjects perceived negative behavior as a sign of unhappiness.

Adolescent↗
PubMed1976

The coronary-prone behavior pattern and the suppression of fatigue on a treadmill test.

A study was conducted to test the hypothesis that Type A (coronary-prone) individuals would show greater suppression of subjective fatigue than Type B (non-coronary-prone) individuals in order to persist at a tiring but challenging task. Type A and Type B college students completed a Balke treadmill test (at a walking pace) while rating their fatigue at 2-minute intervals. Each subject also completed another treadmill test (at a running pace) that was designed to assess maximum aerobic capacity. Subjects' aerobic capacities and their aerobic performance levels attained on the Balke test were determined by analysis of expired air. Each subject's walking performance was scored as a proportion of his maximum aerobic capacity. Analysis of the resulting percentage values indicated greater effort among A's than B's. Moreover, the subjective fatigue ratings of A's were lower than those of B's. The results were discussed in terms of fatigue suppression as an instrumental response for attaining mastery over the environment. consideration was also given to the role of fatigue in the onset of coronary heart disease.

Attitude to Health↗