The longitudinal study had two components. In the first, the Tulane SCOR investigators collected pulmonary function, respiratory health, immunologic, and industrial hygiene data on 300 workers in nine textile plants (six cotton and three synthetic) for comparison with the company's data. In the second component, Tulane investigators worked closely with the participating company to insure the quality of data the company collected in their respiratory health surveillance program on workers in the nine plants.