Respiratory symptoms and pulmonary function in farmers.

A questionnaire was given to 1,824 farmers and 556 control subjects in Saskatchewan to assess respiratory health and pulmonary function tests. With data corrected for age and smoking, farmers were found to have increased prevalences of the respiratory symptoms of phlegm, wheeze, shortness of breath, and the condition of chronic bronchitis. In addition, farmers had significantly lower values for the pulmonary function test variables forced vital capacity (FVC), forced expired volume in one second (FEV1) and maximum midexpiratory flow rate. However, the FEV1/FVC ratio was slightly but significantly greater in farmers than in control subjects. These findings suggest an increase in respiratory symptoms in farmers compared with rural control subjects who are not farmers and a decrease in lung volume and expired flow rates. The slightly high FEV1/FVC ratio may indicate a mixed obstructive and restrictive picture.