What Causes Asbestosis?

Inhaling asbestos fibers causes asbestosis, a serious lung condition characterized by progressive lung tissue scarring. The human body can’t remove every inhaled asbestos fiber, and accumulation of these toxic fibers leads to asbestos-related diseases. 

Asbestos is a naturally occurring mineral used historically by many American industries until its use became regulated in the 1970s. Most asbestos exposure occurs in occupations such as construction, shipping, aerospace engineering and mining.

Key Facts About Asbestosis
  • Asbestosis causes progressive lung scarring such as pulmonary fibrosis and interstitial lung disease.
  • Long-term exposure to asbestos increases the risk of asbestosis.
  • No cure currently exists for asbestosis, but treatment can slow progression and improve symptoms.

Although asbestosis is not cancerous, it is associated with a significantly increased risk of developing pleural mesothelioma, which occurs in the tissue layers covering the lungs, and lung cancer. Other possible asbestosis complications include respiratory failure, cancers of other organs and heart disease.

Risk Factors for Asbestosis

Asbestos exposure is the main risk factor for asbestosis. As people have longer, more intense asbestos exposure, their risk of asbestosis increases. 

All humans are exposed to small amounts of asbestos in the air, water and soil. However, this low-level exposure usually doesn’t cause illness. Most people who become ill from asbestos have a history of frequent, prolonged exposure.

Common Risk Factors
  • Amount of asbestos exposure
  • Asbestos fiber size, shape and makeup
  • Exposure source
  • Inherited genetic factors
  • Length of time of exposure
  • Preexisting lung disease
  • Smoking

Asbestosis shares many risk factors with mesothelioma. As a result, people with these risk factors who develop asbestosis also have an increased risk of developing mesothelioma. 

Where Does Asbestos Exposure Occur?

Most asbestos exposure occurs in the workplace. Direct exposure can occur through direct physical contact with asbestos-containing products or through breathing in small particles. Indirect exposure, also known as secondary exposure, occurs when someone comes into contact with asbestos fibers on clothing, furniture or another person’s body.

Sources of Asbestos Exposure
  • Asbestos Products: Because of its popular use in American industry prior to the 1970s, asbestos appears in a wide range of materials and products. These include building materials, automotive parts, cement and adhesives, among others.
  • Environmental Asbestos: Asbestos exposure in the environment occurs when mining, disturbing of natural asbestos deposits or processing of asbestos ore releases asbestos fibers into the air. Hurricanes, tornadoes, earthquakes and other natural disasters can also release asbestos fibers.
  • Occupational Exposure: Most occupational asbestos exposure affects construction workers, firefighters, industrial workers, power plant workers, shipyard workers and U.S. Navy veterans who worked in these occupations prior to the 1970s. The profession with the greatest potential for dangerous asbestos exposure is asbestos mining, which ended in the U.S. in 2022.
  • Secondary Exposure: People exposed to asbestos indirectly have secondary asbestos exposure. People working with asbestos often brought asbestos fibers home to their families unknowingly on their clothing and bodies.

Asbestos exposure remains a significant concern for workers and others at risk of exposure. The U.S. Environmental Protection Agency is working to improve safety standards to reduce asbestos exposure risk. As of March 2023, the EPA was collecting further data about asbestos dangers to support its proposed ban on ongoing asbestos use. 

Latency Period of Asbestosis

Asbestosis can have a long latency period, with symptoms usually taking between 20 and 30 years to develop after the initial exposure to asbestos. However, this period can shorten significantly for people exposed to greater amounts of asbestos, such as shipbuilders and insulation workers. 

Other asbestos-related diseases, including mesothelioma and lung cancer, can also take decades to develop after exposure. A recent study in South Korea examined the latency period of mesothelioma and lung cancer related to asbestos exposure. Researchers found that job type, asbestos type and the initial age at exposure have a significant effect on the latency period in addition to the amount and duration of the exposure. 

Fortunately, imaging tests can identify signs of asbestosis before symptoms arise. If you’ve been exposed to asbestos and feel out of breath occasionally, it’s important to discuss this with your doctor so they can recommend appropriate screening tests. 

Asbestos-Related Diseases

There are other asbestos-related diseases in addition to asbestosis. Some of these diseases are malignant, or cancerous; others are benign, or noncancerous.

Malignant Diseases
  • Colon cancer
  • Laryngeal cancer
  • Lung cancer
  • Mesothelioma
  • Ovarian cancer
  • Pharyngeal cancer
  • Stomach cancer
Benign Diseases
  • Asbestosis
  • Atelectasis (partial lung collapse)
  • Hyaline pleural plaques
  • Pericardial effusion (fluid around the heart)
  • Peritoneal effusion (fluid accumulation in the belly)
  • Pleural effusion (fluid in the pleural cavity)
  • Pleural thickening

When it occurs in isolation, without signs or symptoms of cancer, the disease is benign. Although benign cases are considered less serious than malignant ones, they can still be life-threatening. 

Preventing the Development of Asbestosis 

Preventing asbestosis requires avoiding asbestos exposure. People who work in environments with significant exposure need to be proactive in order to limit their risk. Workers can reduce their exposure by ensuring their employer follows regulations and that they have proper training and certification to work with asbestos. 

It’s important to know where asbestos exposure happens in order to prevent it. For example, if you’re working on a home renovation or demolition, check for asbestos beforehand if the home’s construction predates 1980. Avoiding old asbestos insulation products can also reduce exposure risk. If you discover asbestos in your home, you shouldn’t remove it yourself. A professional must assist with the disposal process. 

These methods are useful for preventing mesothelioma and other asbestos-related diseases. If you think you have experienced asbestos exposure or have an asbestos-related disease such as asbestosis, you should talk with your doctor about testing and prevention strategies to avoid future exposure.