438Original Article Airway Function and Respiratory Resistance in Taiwanese Coal Workers with Simple Pneumoconiosis

Background: Occupational exposure to coalmine dust consisting of coal particles and free silica eventually results in massive lung fibrosis. However, clinical observa-tions of patients with coal workers ’ pneumoconiosis (CWP) suggest that air-way dysfunction may be a predominant feature in the initial development of the disease. Methods: Forced expirogram, plethysmographic determination of lung volumes, and measurement of respiratory resistance (Rrs) by the forced oscillation tech-nique at 3, 9, and 18 Hz were conducted in a sample of 71 coal miners with simple pneumoconiosis and 36 healthy subjects. Results: The forced vital capacity (FVC) was well-preserved even in miners with cat-egory 2 and 3 CWP. There were no differences in the mean forced expiratory volume in 1 second (FEV1) values between healthy subjects and miners wit