Abstract

The ventilatory capacity of 46 men exposed to jute dust in the manufacture of felt and wadding was estimated at the beginning and end of shifts on the first and last days of a working week. A smoking history was obtained from all subjects, and for those speaking English a more detailed questionnaire on respiratory symptoms was completed. Each man was also instructed to cough under observation, and a loose cough, as judged by ear or by production of a sputum specimen was recorded as productive. A significant mean decrease in forced expiratory volume at one second was observed in the series as a whole on the first day at work, but no significant change was found over the final day nor over the entire week. Closer analysis reveals that this decrease was largely confined to those with a productive cough on request, and to those who smoked, most of the former group being smokers. In these groups the decrease observed on the first day tended to persist throughout the week. Insofar as those who smoked, and particularly those who had a productive cough, tended to have a lower F.E.V._1·0, expressed either in absolute units or as a percentage of the forced vital capacity, the men with the greater initial impairment of ventilatory capacity showed the more significant decreases on exposure to dust. Evidence is produced to suggest that the sign of productive cough defines better than the history a group with a lower ventilatory capacity and a greater tendency to react to inhaled irritants.