Chest pain in rubber chemical workers exposed to carbon disulphide and methaemoglobin formers.

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 weTe 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 Coronary artery disease has been associated with chronic exposure to CS2.'-5 Acute adverse effects on the heart may occur as a result of exposure to methaemoglobin formers because of reduced Oxygen supply to the myocardium.6 The purpose of the present study was to determine (1) the prevalReceived 20 January 1983 Accepted 6 June 1983 ence of chest pain in A, (2) the prevalence of coronary heart disease (CHD) in A, (3) whether either prevalence exceeded the expected, and (4) whether the chest pain reported was the result of acute or chronic effects of workplace exposures, or both.There are no reports in the English language of excess cardiovascular mobidity and mortality in rubber chemical workers exposed to CS2 but an increased prevalence of cardiovascular disease has been reported in viscose rayon textile workers exposed to CS2. Tiller et al carried out one of the early controlled studies of the effects of long term exposure to relatively low levels of CS2' and found that the death rate for CHD among men aged 45 to 64 working in the spinning department of a viscose rayon factory exceeded the expected by a factor of 2 in those with more than ten years' employment. Comparing a group of Finnish viscose rayon workers with a group of controls, Hemberg et a12 and Tolonen et a13 5 found an increased death rate from CHD 296

Cardiovascular diseases and the work environment. A critical review of the epidemiologic literature on chemical factors.

“…The relationship between carbon disulfide and IHD has been confirmed during the 1980s in American studies (255,256), of which the latest (256) is the largest ever undertaken, the cohort studied comprising more than 10 000 workers .…”

Critical review of the epidemiological literature on the potential cardiovascular effects of occupational carbon disulfide exposure

“…The studies by Franco et al, Oliver and Weber,Stanosz et al and Sugimoto et al [10,38,47,50,51] were problematic for several reasons. None of these assessed or controlled for confounding by cardiac risk factors other than age and gender, and limited analyses of exposure precluded the assessment of the effect of duration or presence of a dose-response relationship.…”

“…Four used matching in the construction of the study populations, but reported unmatched analyses with no explanation [4,9,10,51]. Three reported low and differential participation rates for the exposed and unexposed cohorts [1,8,43], and one reported analyses of rubber industry employees who experienced very low levels of exposure to CS 2 in addition to a number of additional, potentially cardiotoxic exposures that were unlikely to be adequately controlled for in the analysis [38]. Although these papers were inadequate for inclusion in a quantitative assessment of the effect of low-level exposure to CS 2 , their results were influential in our overall conclusions, and are therefore summarized in the text that follows.…”

“…Oliver and Weber [38] investigated the effect of exposure to CS 2 and other chemical agents in 89 potentially exposed US rubber workers and 65 unexposed workers from the same plant (Table 2). Unspecified chest pain and possible or definite angina were reported by a significantly higher proportion of exposed (50% for chest pain, 36.4% for angina) than unexposed workers (20% for chest pain, 7.6% for angina; P<0.0002 and P<0.008 respectively).…”

Re: Response to: Mortality among rubber chemical manufacturing workers by M.M. Prince et al. Am. J. Ind. Med. 2000. 37:590–598. I. Reply to Valentgas et al.'s letter to the editor

“…The existence of an intervention program with evaluation of cardiac risk factors from 1975 on would appear to make the ®ndings of Oliver and Weber (1984) of increased chest pain and possible/de®nite IHD among workers in the rubber chemicals department examined in 1980, and our ®nding of increased IHD mortality in the 1980±1994 time period, of even greater concern.``H owever well intended the authors' recommendations, they are not well supported by the results of the study.' ' We continue to believe that the presentation of results was well balanced in this paper and that the recommendations are reasonable.…”