Chemical and nonchemical causes of occupational heart disease were reviewed. Several chemical agents were considered to have a direct effect on the myocardium. Evidence for a direct causal relationship between carbon-disulfide (75150) and coronary artery disease (CAD) was strongest. Epidemiologic studies of cardiovascular disease in exposed workers from Pennsylvania, Finland, and Belgium were quoted. Researchers in Japan found no increased CAD in exposed workers, but a striking increase in retinal microaneurysms. The association between CAD and occupational exposure to nitroglycerin (55630), ethylene-glycol-dinitrate (628966) and other aliphatic nitrates, carbon-monoxide (630080), nonhalogenated and halogenated industrial solvents, arsenic (7440382), and cobalt (7440484), as well as blood pressure problems caused by cadmium (7440439) and lead (7439921) were discussed. Passive smoking was described as an important public health factor in deaths from CAD. Nonchemical factors in occupational CAD were shift work, noise, and stressors due to organization, work or psychosocial factors. Cardiac disease secondary to occupational lung disease was a result of pulmonary hypertension. The prevalence of CAD was reduced in occupations with very high levels of energy expenditure.