A Study on the Ventilatory Function of Coal Miners

Abstract

Clinically,coal workers'pneumoconiosis (CWP) may result in several pulmonary functional abnormalities. In order to further understand the patterns of ventilatory defect of patients with CWP in Taiwan, this study collected 98 coal miners includind 25 with X-ray category 0, 49 with simple pneumoconiosis and 24 with progressive massive fibrosis (PMF )。 Tests were conducted to determine their ventilatory function, lung volumes and airway resistance (Raw). Our data revealed that patients with CWP demonstrated a normal FVC ( forced vital capacity) and a normal TLC (total lung capacity ). However, expiratory flow parameters such as FEV1 (forced expiratory volume in 1s) and FEV1/FVCwere decreased . The maximal expiratory flow-volume curves in approximately half (49%) of the patients with simple pneumoconiosis were normal , and were of a obstructive pattern in additional 43% of them. The types of ventilatory defect did not vary with shapes of small opacities in simple pneumoconiosis. Remark- able reduction in FVC and TLC were observed mainly in patients with PMF. However, Raw was consistently elevated in all groups, even in patients with category 0 of CWP. We conclude that CWP in Taiwan, from functional point of view, is primarily manifested with an obstructive ventilatory defect.