Change Date

VIII.iii.7.A.1.a.  Entitlement to Compensation for Conditions Based on Exposure to Asbestos

• in-service asbestos exposure, and
• a diagnosed disability that has been associated with in-service asbestos exposure.

Introduction

• definition of asbestos
• general effects of asbestos exposure
• prevalence of specific diseases resulting from exposure to asbestos
• latent period for development of disease due to exposure to asbestos, and
• diagnostic indicators of asbestosis.

Change Date

VIII.iii.7.A.2.a.  Definition:  Asbestos

• steam pipes for heating units and boilers
• ceiling tiles
• roofing shingles
• wallboard
• fire-proofing materials, and
• thermal insulation.

VIII.iii.7.A.2.b.  General Effects of Asbestos Exposure

• fibrosis, the most commonly occurring of which is interstitial pulmonary fibrosis, or asbestosis
• tumors
• pleural effusions and fibrosis
• pleural plaques (scars of the lining that surrounds the lungs)
• mesotheliomas of pleura and peritoneum, and
• cancers of the
  • lung
  • bronchus
  • gastrointestinal tract
  • larynx
  • pharynx, and
  • urogenital system, except the prostate.

Note:  The biological actions of the various fibers differ in some respects, in that

• chrysotile products
  • have their initial effects on the small airways of the lung
  • cause asbestosis more slowly, and
  • result in lung cancer more often, and
• crocidolite and amosite
  • have more initial effects on the small blood vessels of the lung, alveolar walls, and pleura, and
  • result more often in mesothelioma. 

VIII.iii.7.A.2.c.  Prevalence of Specific Diseases Resulting From Exposure to Asbestos

• lung cancer that
  • originates in the lung parenchyma rather than the bronchi, and
  • eventually develops in about 50 percent of persons with asbestosis
• gastrointestinal cancer that develops in 10 percent of persons with asbestosis
• urogenital cancer that develops in 10 percent of persons with asbestosis, and
• mesothelioma that develops in 17 percent of persons with asbestosis.

• All persons with significant asbestosis develop cor pulmonale (enlargement of the right ventricle of the heart) and heart disease secondary to disease of the lung or its blood vessels.  Those persons who do not die from cancer often die from heart failure secondary to cor pulmonale.
• Disease-causing exposure to asbestos may be
  • brief, and/or
  • indirect.

• Current smokers who have been exposed to asbestos face an increased risk of developing bronchial cancer.
• Mesotheliomas are not associated with cigarette smoking.

VIII.iii.7.A.2.d.  Latent Period for Development of Disease Due to Exposure to Asbestos

VIII.iii.7.A.2.e.  Diagnostic Indicators of Asbestosis

• dyspnea on exertion
• end-respiratory rales over the lower lobes
• compensatory emphysema
• clubbing of the fingers at late stages, and
• pulmonary function impairment and cor pulmonale that can be demonstrated by instrumental methods.