In response to epidemiological studies reporting an excess mortality from nonmalignant and malignant lung disease among foundry workers, mortality rates were surveyed for 278 male iron foundry workers employed for at least 10 years at a gray iron foundry. The men died between 1970 and 1981. Standardized proportional mortality ratios for nonmalignant respiratory disease (primarily lung emphysema and pneumonia deaths), lung cancer, and leukemia were significantly higher (177, 148 and 248, respectively) for white foundry workers than for the general white population; nonwhites had a significant excess in proportional mortality due to circulatory diseases (143). Significant, positive, duration dependent associations between nonmalignant respiratory disease, lung cancer, and work in finishing departments were observed for white males; excess proportional mortality was reported only for nonmalignant respiratory disease for whites employed in the core room. After allowing for the effects of age, history of employment in coal mining or foundries, and smoking, case control studies revealed a significant association between nonmalignant respiratory disease and finishing work. When controlling for the same factors, the association between lung cancer and finishing work was positive, but not significant. Available historical industrial hygiene data suggested that silica (7631869) exposure was widespread throughout the plant and not limited to the finishing and core areas. The authors conclude that the dust distribution does not convincingly explain department differences in nonmalignant respiratory disease and that the finding of cardiovascular disease mortality among the nonwhites is consistent with the fact that these workers were exposed to heat and carbon-dioxide (124389).