Small airways disease in coal miners. A longitudinal study.
Hall DR; Lapp NL; Reger R; Seaton A
Bull Physio-Pathol Respir 1975 Oct; 11(5):863-877
Seventeen of an original cohort of 25 non-smoking coal miners with simple pneumoconiosis in the absence of large airway obstruction and six age-matched controls studied in 1969 are re-examined in 1973 for respiratory mechanics. Miners, when compared with controls, show a marked decline in maximal expiratory flow at mid-vital capacity without significant change in the one-second forced expiratory volume. In addition, nine miners show abnormal elevated closing capacity expressed as a percentage of total lung capacity (CC/TLC) percent, and four show abnormal closing volume as a percentage of vital capacity (CV/VC) percent. The presence of an elevated (CC/TLC) percent and (CV/VC) percent correlate mainly with the presence of hyperinflation as indicated by an elevated residual volume.
NIOSH-Author; Hazards; Respiratory-system-disorders; Coal-mining; Mining-industry; Respiratory-functions; Lung-volume; Respiratory-airflow; Lung-fibrosis
Bulletin de Physio-Pathologie Respiratoire