The main risk factor for pleural and peritoneal mesothelioma cancer is asbestos exposure. Almost all cases of mesothelioma cancer can be linked to asbestos exposure. When people inhale asbestos fibers, they stick to the mucus in the air passages like the nose and throat. If they are not coughed up, the fibers can travel to the ends of the small airways and penetrate into the lung and chest wall. These fibers may then directly injure cells of the chest wall, and eventually cause mesothelioma cancer. This is called pleural mesothelioma.

People may also cough up and swallow asbestos fibers, which can cause mesothelioma cancer in the abdomen. This is called peritoneal mesothelioma.

Researchers are still studying exactly how asbestos causes cells to develop into mesothelioma cancer. Asbestos fibers may damage a person's DNA, causing cells to grow uncontrollably.

The amount of asbestos a person has been exposed to and the length of time they were exposed affects the risk of developing mesothelioma. People most likely to develop mesothelioma cancer are:

• Those exposed to asbestos at a young age
• Those exposed to asbestos for a long period of time
• Those exposed to high levels of asbestos

Unfortunately, the risk of developing pleural and peritoneal mesothelioma cancer does not decrease with time after exposure to asbestos.

If you have any of these risk factors for developing mesothelioma cancer, you may wish to visit the Mesothelioma Diagnosis Support Center.