A survey was conducted among 266 railroad workers to determine exposures to asbestos (1332214). Of the workers, 65 percent had a minimum of 2 years of tenure in the railroad shop environment prior to 1950. The testing program included administration of a questionnaire detailing previous occupations and smoking history. Chest radiography was performed and evaluated. Most participants were between 60 and 69 years of age and had been employed in an asbestos environment for less than 10 years. Of the participants, 43 percent were 30 to 39 years from initial exposure, and 57 percent were 40 or more years from initial exposure. Pleural abnormalities were found in 20 percent of workers examined. Evidence of pneumoconiosis was found in 3 percent. In six of eight workers with pneumoconiosis, irregular small opacities predominated and rounded opacities alone were seen in two others. Of the six with irregular opacities, three had associated pleural abnormalities. Boiler makers and machinists had 33 and 30 percent, respectively, of pleural abnormalities. No difference in prevalence rates was seen after adjustment for smoking. Pleural abnormalities were present in 6 of 38 workers who had exposures to other noxious dusts. The authors conclude that a history of asbestos mortality and morbidity among steam era railway workers exists.