Factors associated with early-stage pulmonary fibrosis as determined by high-resolution computed tomography among persons occupationally exposed to asbestos

Scand J Work Environ Health. 2004 Jun;30(3):206-14. doi: 10.5271/sjweh.781.


Objectives: Asbestosis remains difficult to diagnose, particularly in its early stages. The aim of this study was to determine criteria for independently associated features of pulmonary fibrosis in high-resolution computed tomograms among persons occupationally exposed to asbestos.

Methods: Retired persons with documented occupational asbestos exposure and no known asbestos-related diseases were assessed for occupational, clinical, functional respiratory, and chest X-ray criteria. In addition, they all underwent high-resolution computed tomography (HRCT) in the prone position.

Results: Altogether 51 (7.2%) of the 706 enrolled participants had features of pulmonary fibrosis consistent with asbestosis in the HRCT. Among those with small irregular opacities of <1/0 according to the 1980 International Labour Office Classification (ILO-C) in their X-rays, 5% had asbestosis in the HRCT. In a multivariate analysis, only age [odds ratio (OR) per year 1.08, 95% confidence interval (95% CI) 1.02-1.14], cumulative-exposure index (CEI) for asbestos (OR 6.4, 95% CI 1.5-28.4 for a CEI of > or =100 fibers/ml x years), and the presence of small irregular X-ray opacities of > or =1/0 ILO-C (OR 3.0, 95% CI 1.6-6.0) were independently associated with HRCT asbestosis. No combinations of these criteria simultaneously yielded high sensitivity and specificity for the diagnosis of early-stage HRCT asbestosis. Moreover, only 2% of the persons with a CEI of <25 fibers/ml x years had HRCT asbestosis, the finding confirming the low incidence of asbestosis for such low exposure, as previously reported on the basis of X-ray data.

Conclusions: Additional research is needed to better identify the persons most likely to benefit from HRCT screening for asbestosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Asbestos / toxicity
  • Asbestosis / diagnostic imaging*
  • Asbestosis / epidemiology
  • Asbestosis / etiology
  • Female
  • France / epidemiology
  • Humans
  • Interviews as Topic
  • Male
  • Mass Screening
  • Middle Aged
  • Occupational Exposure / adverse effects*
  • Occupational Exposure / analysis
  • Physical Examination
  • Plethysmography
  • Pulmonary Fibrosis / diagnostic imaging*
  • Pulmonary Fibrosis / epidemiology
  • Pulmonary Fibrosis / etiology
  • Retirement
  • Risk Factors
  • Sensitivity and Specificity
  • Smoking / adverse effects
  • Tomography, X-Ray Computed*
  • Total Lung Capacity / physiology


  • Asbestos