The respiratory effects of chloromethyl methyl ether.

A prospective study of 125 chemical workers was carried out for ten years to investigate the incidence of lung cancer. Some of the men were exposed to chloromethyl methyl ether containing bis(chloromethyl) ether as an impurity. Bronchogenic carcinoma was markedly increased among them, with a strong dose-response relationship. An unexpected inverse relationship was noted between smoking and the incidence of lung cancer. The neoplasms (all small-cell carcinomas) occurred in relatively young men. Symptoms of chronic bronchitis were reported more often among men exposed to chloromethyl ether, and a dose-response relationship was apparent, with smoking a cofactor. Ventilatory function was not significantly affected by chemical exposure. Periodic screening over the first five years of the study showed a decrease in chronic coughing and an increase in dyspnea while chemical exposure was diminishing.