Asbestos enters our bodies by inhaling airborne particles, or ingesting those that land in food or drink. Some of the asbestos fibers are inhaled and rain out in saliva and are swallowed. Others are inhaled and either work their way through our lung tissue and lodge in the lining that surrounds the lungs. Other particles are trapped in mucous that is naturally flushed out of our lungs and swallowed. Particles that are swallowed can penetrate our stomachs and lodge in the peritoneal lining around the stomach. Asbestos exposure can cause asbestosis, mesothelioma and more rarely or indirectly, lung cancer, especially in smokers.
Once these fibers lodge in body tissue, they tend to stay in place where they cause irritation, inflammation and scarring. Depending upon where they lodge, they can cause different diseases.
Asbestosis is a fibrotic disease of the lungs. Asbestos fibers trapped in the lung tissue cause inflammation that in turn grows scar tissue as the tissue heals. Scar tissue is more fibrous than the tissue it healed over, and is less elastic than lung tissue. Because it hasn't got the same flexibility, it cannot expand and contract, and restricts the ability of the lungs to inhale as deeply as they should. Not only is asbestos a fibrotic disease is it a chronic restrictive lung disease.
Mesothelioma is another common disease associated with asbestos exposure. When the asbestos fibers work their way completely through the lungs, they can still lodge in the mesothelial lining that wraps around the lungs. Here they cause inflammation, plaques, and scar tissue that can, after many years, develop into a malignant tumor.
Asbestos fibers can enter the stomach either through directly ingesting them. If airborne particles land on food or in drinks, this would give them direct entry to the stomach. Other particles that are inhaled can adhere to the moisture in a person's mouth or throat and simply be swallowed. Fibers that were inhaled into the lung might simply be flushed out as cilia in the lungs move mucous out in a normal cleansing process, or can be coughed up and swallowed.
Asbestos fibers that are swallowed can move through the stomach muscles into the abdominal wall that is lined with mesothelium, where it is called the peritoneum. As with the pleural mesothelium, fibers can cause inflammation and scarring, and eventually, tumors.
Far more rarely do asbestos fiber cause testicular mesothelioma or pericardial mesothelioma. In Testicular mesothelioma the peritoneal sac that lines the abdomen just above the testicles has developed cancerous cells. Pericardial mesothelioma involves the membrane that lines the cardiac cavity and the heart itself.