Respiratory function and bronchial reactivity in mill workers.

Professional exposure to vegetable dusts affect the respiratory function of the exposed subjects. A previous survey conducted in an industrial flour-mill demonstrated a higher frequency of respiratory symptoms in workers compared to a control group. Ten subjects employed in a work site particularly exposed to dust were studied. Each subject answered a questionnaire and performed on Mondays and Fridays, at the beginning and end of his work shift, a flow volume curve and an isocapnic hyperventilation test. The aerobiology of the professional environment was also measured. We noted: 1) in the flow volume curves: a drop in the FEV1 during the Monday morning shift, a significant difference between the FEV1 (p less than 0.05) and the MMEFR 25-75 (p less than 0.05) measured at 6 am on Monday and Friday, and between the MMEFR 25-75 values obtained at 12 noon on Monday and Friday (p less than 0.05). 2) after isocapnic hyperventilation, a significant drop in the MMEFR 25-75 at 6 am on Monday (p less than 0.01) and in the FEV1 and MMEFR 25-75 at 12 noon on Mondays (p less than 0.05), a significant drop in the FEV1 at 1 pm on Monday (p less than 0.01).