Twenty-three papers including work in progress as well as previously published data were considered (1-23). Populations at risk are 500 000 workers in the United States (4), and 30 000 in Canada (2) (excluding farmers) who are employed in the grain storage and transporting industry. These include elevator agents, dock workers, longshoremen, mill workers, and bakers (3). Nonpulmonary manifestations of grain dust exposure include skin irritation, conjunctivitis, and irritation of the nose and sinuses (1-11, 13, 15-21). Although these were recognized as important, no information was presented to explain their pathogenesis. The pulmonary manifestations include chronic cough with sputum production,