Asbestos causes malignant pleural mesothelioma decades after a person inhales asbestos dust. The mineral’s needle-like fibers lodge in the lungs and gradually migrate into the pleural lining.



Plaque forming on the pleural lining of the lungs
Over a long period of time, asbestos fibers cause irritation, chronic inflammation and genetic changes that turn cells cancerous.

These cancerous cells grow fast and uncontrollably, threatening the organs around them.

Two layers make up the pleura lining. The outer layer lines the entire inside of the chest cavity, and the inner layer covers the lungs.

A malignant tumor can develop on either layer and quickly spread to the other layer. As tumors develop on the pleural surface, they grow to form a mass around the affected lung

Mesothelioma was virtually unknown until the 20th century. After decades investigating the disease, medical researchers identified the cause: Asbestos exposure. Mesothelioma rates rose as industries expanded the use of asbestos.

Diagram showing how asbestos exposure affects the body
Diagram of mesothelioma causes by location.
Research studies proved inhaling or swallowing microscopic asbestos fibers can start a chain reaction that leads to several types of cancer. The toxic dust can also cause asbestosis, an incurable breathing disorder.

In March 2009, the International Agency for Research on Cancer (IARC) reconfirmed asbestos exposure as the leading cause of mesothelioma. All forms of asbestos cause the disease.

Two years later, the IARC presented an update on the link between asbestos and cancer at a World Health Organization conference in Spain. They explained the scientific evidence has strengthened over time. There is now overwhelming proof asbestos is carcinogenic to humans, regardless of the type or fiber length.

Main Risk Factors for Mesothelioma


  • Working at an asbestos mine or asbestos-processing plant
  • Working in a high-risk occupation such as construction or heavy industry
  • Serving on military ships or facilities built with products containing asbestos
  • Living in a residential area near an asbestos mine or contaminated site
  • Disturbing asbestos products during a home renovation without proper safety measures