Relationship of pulmonary function to radiographic interstitial fibrosis in 2,611 long-term asbestos insulators. An assessment of the International Labour Office profusion score

Am Rev Respir Dis. 1992 Feb;145(2 Pt 1):263-70. doi: 10.1164/ajrccm/145.2_Pt_1.263.


Radiographic evidence of interstitial fibrosis (IF) secondary to asbestos inhalation (using the International Labour Office [ILO] profusion of small irregular opacities) was compared with FVC as an independent indicator of IF. In addition, spirometric indices of airflow (FEV1/FVC and FET25-75%) were correlated with the radiographic profusion score. A study of 2,611 long-term insulators was well designed for these analyses since all subjects were from the same trade, there were sufficient (n = 515) nonsmokers to assess the effects of asbestos exposure in the absence of smoking, most (60%, n = 1,557) of the workers had parenchymal abnormalities (scores greater than or equal to 1/0), and there was a greater prevalence of high scores than in other published series (347 workers or 13.3% had scores greater than or equal to 2/1). Looking at all subjects, the FVC decreased as profusion score increased. The FVC was abnormal (88.0% of predicted) even when the profusion score was clearly normal (0/0). The FVC was lower at any score in smokers and in workers with pleural thickening (more so with diffuse thickening). There was, however, no difference in FVC between intermediate scores 0/1 versus 1/0 and 1/2 versus 2/1. Airflow increased with greater profusion, tending to overcome a decrease seen at lesser profusion scores. These results provide a greater understanding of the relationships among profusion scores, smoking, pleural diseases, and pulmonary function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Asbestosis / diagnosis*
  • Asbestosis / diagnostic imaging
  • Forced Expiratory Volume
  • Humans
  • Lung / diagnostic imaging*
  • Maximal Midexpiratory Flow Rate
  • Middle Aged
  • Occupational Diseases / diagnosis*
  • Occupational Diseases / diagnostic imaging
  • Occupational Diseases / etiology
  • Pulmonary Fibrosis / diagnosis*
  • Pulmonary Fibrosis / diagnostic imaging
  • Pulmonary Fibrosis / etiology
  • Radiography
  • Smoking
  • Spirometry*
  • Vital Capacity