Abstract

A cross sectional prevalence study of chest pain in 94 rubber chemical workers exposed to carbon disulphide (CS2) and methaemoglobin forming aromatic amines was carried out. The purpose of the study was to determine whether the prevalence of chest pain or coronary heart disease (CHD), or both, in exposed individuals exceeded that of a group of non-exposed individuals from the same plant. Cardiovascular, smoking, and occupational histories were obtained. Blood pressure, height, weight, serum cholesterol, and fasting blood glucose were measured. Resting electrocardiograms (ECGs) were obtained on all study participants, as were exercise stress tests on selected exposed individuals. Matching eliminated important known risk factors for coronary artery disease. Both chest pain and angina were significantly related to exposure, controlling for age and cigarette smoking. This association was not dependent on duration of exposure as defined by 10 or more years of employment in the department of interest. CHD as defined by angina, a history of myocardial infarction, or a coronary ECG or a combination of these occurred more frequently among exposed workers. The number of abnormal ECGs in the exposed group was twice that in the control group, but the difference was not statistically significant. Age rather than exposure appeared to be the important variable associated with raised blood pressure. Neither biological measures of exposure nor ECGs showed an acute effect of workplace exposures on the myocardium. Possible additive or multiplicative effects of individual chemical agents could not be evaluated. Appropriate modification of medical surveillance of rubber chemical workers with exposure to CS2 and aromatic amines is warranted.