Mesothelioma is cancer of the mesothelial cells, which surface many of the internal body organs as a lining. It is often found in the lungs, where it is known as pleural mesothelioma, and due to proximity can also affect the lining that covers the heart.

Benign mesothelioma is a type of non-cancer mesothelioma which usually develops in the reproductive organs as well as being able to appear in the lining of the lungs. These, however, are rare, and can develop in both men and women. In the majority of cases, the malignant form is usually caused by exposure to asbestos particles. Although, for the most part, exposure is job-related, caused by regular inhaling of airborne asbestos fibres and dust, indirect exposure includes the washing of clothes that have become contaminated with the particles. A common job that exposes the worker and family members to such a risk is home renovations in which asbestos cement products are being used.