Discussion
Both acute, shift related effects'0 and chronic, accelerated lung volume loss" associated with cotton dust exposure are described in the literature. The design of this study did not enable us to measure across shift changes and measurements were made as near the beginning of each shift as possible to attempt to reduce any "acute" effect of cotton dust exposure. Lung function data were available in most of the operatives in this study. Fourteen operatives either refused to have the investigation performed for varying reasons or were unable to produce a satisfactory reproducible spirometric curve.