Merck Manual

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Carrie A. Redlich

, MD, MPH, Yale Occupational and Environmental Medicine Program Yale School of Medicine;

Efia S. James

, MD, MPH, Yale School of Medicine;

Brian Linde

, MD, MPH, Yale Occ and Env Medicine Program

Reviewed/Revised Nov 2023

Asbestosis is widespread scarring of lung tissue caused by breathing asbestos dust..

  • Asbestosis causes shortness of breath and a decreased ability to exercise.

  • Diagnosis is usually made with chest x-rays and computed tomography.

  • Treatments include giving oxygen and other measures to ease breathing.

  • Asbestosis can be prevented by minimizing exposure to asbestos.

Asbestos is a family of naturally occurring silicates (which are a type of mineral) whose heat-resistant and structural properties are useful in construction and shipbuilding materials, automobile brakes, and some textiles.

Asbestosis is a form of interstitial lung disease Overview of Interstitial Lung Diseases Interstitial lung disease (also called diffuse parenchymal disease) is a term used to describe a number of different disorders that affect the interstitial space of the lungs. The interstitial... read more caused by asbestos exposure. The period between exposure to asbestos and disease presentation is usually 20 to 40 years. Asbestosis appears earlier in people who have had longer and more intense exposure to asbestos.

Risk factors

Direct occupational exposure remains the predominant cause of asbestos-related disease. In most developed countries, asbestos use has declined over the past several decades. Asbestos can still be found in old building materials and some products, and today most occupational exposures occur during repair, renovation, removal, or maintenance of asbestos-containing products installed in prior eras. Workplace exposure levels were generally much higher in the past.

Occupations that were traditionally associated with highest risk of exposure include construction trades (insulators, pipefitters, carpenters, electricians, roofers, drywall workers), maintenance workers, shipyard workers and Navy personnel, boilermakers and furnace workers, auto brake mechanics, and individuals involved with asbestos mining and processing.

Symptoms of Asbestosis

Symptoms of asbestosis appear gradually. The first symptoms are a mild shortness of breath and a decreased ability to exercise.

Generally, asbestosis progresses slowly over many years and can continue to progress after the person is no longer exposed to asbestos.

Diagnosis of Asbestosis

  • A history of asbestos exposure

  • Chest imaging (x-ray or preferably high-resolution computed tomography)

Diagnosis of asbestosis is based on history of exposure to asbestos and chest imaging, such as chest x-ray or high-resolution computed tomography (CT).

Bronchoalveolar lavage (a minimally invasive procedure that involves instilling sterile salt water into the lungs, then removing the fluid for analysis) or lung biopsy is potentially useful when the diagnosis is uncertain. The demonstration of asbestos fibers and/or asbestos bodies can help support the diagnosis but is not necessary.

A lung biopsy is rarely needed to make the diagnosis.

Treatment of Asbestosis

  • Treatments to relieve symptoms

No specific treatment exists. People should avoid further asbestos exposure.

Most treatments for asbestosis aim to ease symptoms. Oxygen therapy Oxygen Therapy Oxygen therapy is a treatment that delivers extra oxygen to the lungs when the level of oxygen in the blood is too low. Oxygen is a gas that makes up about 21% of the air we breathe. The lungs... read more Oxygen Therapy relieves shortness of breath. Medications and other measures, including limiting salt intake and losing weight if necessary, can help relieve heart failure.

Antifibrotic agents (for example, pirfenidone and nintedanib) and immunosuppressive drugs (for example, cyclophosphamide and azathioprine) used in other interstitial lung diseases may be effective.

Prognosis for Asbestosis

Asbestosis typically progresses slowly over many years. Many people have mild symptoms and do well, whereas some develop progressive shortness of breath. A few develop respiratory failure and heart failure.

People with asbestosis have a significantly increased risk of lung cancer. Additionally, smoking increases lung cancer risk in people exposed to asbestos.

Prevention of Asbestosis

Preventive measures include eliminating exposure, asbestos abatement in occupational and nonoccupational settings, and smoking cessation Smoking Cessation Most people who smoke want to quit and have tried doing so with limited success. Effective tools to help quit smoking include counseling, nicotine replacement products, and medications. While... read more . People who smoke and have been in contact with asbestos can reduce their risk of lung cancer by giving up smoking and should follow CT lung cancer screening recommendations.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Cyclophosphamide, Cytoxan, Neosar
Azasan, Imuran
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