A Rare Form of Cancer, Malignant Mesothelioma,

According to The National Cancer Institute, malignant mesothelioma, a rare form of cancer, is a disease in which cancer (malignant) cells are found in the sac lining of the chest (pleura), the abdomen (peritoneum), or the heart (pericardium). Most people diagnosed with mesothelioma have worked on jobs where they breathed asbestos. Asbestos may cause a variety of diseases, from non-cancerous forms such as asbestosis, to much more serious diseases such as mesothelioma. Workers exposed to asbestos in the 1940s, 50s, 60s, and 70s, are coming down with these diseases decades later due to the long latency period associated with all asbestos disease.

The Department of Health and Human Services, the World Health Organization, and the Environmental Protection Agency have determined that asbestos is a human carcinogen. It is well documented that breathing asbestos fibers can increase the risk of cancer in people. Exposure to asbestos has been considered a major occupational health hazard since the first adverse effects were noted in the mid-20th century. At that time, there appeared to be an association between asbestos and lung cancer. Subsequently, it was noted that asbestos also caused pleural thickening. By the 1960s, a definite association between asbestos and mesothelioma, a rare cancer of the lining of the lung or the lining of the abdominal cavity was apparent.

The association between lung cancer and asbestos exposure is now well established. Although in most studies, all histologic types of cancer are seen, there appears to be a preponderance of adenocarcinoma. Lung cancer in asbestos-exposed workers is thought to occur at a slightly younger age than other lung cancers, and these cancers are more commonly located in the lower lobes of the lungs. There is what is called a "synergistic effect" between cigarette smoking and asbestos exposure, thus the risk of getting lung cancer rises to extraordinarily high levels if the exposed person is also a smoker. If you have been exposed to asbestos, you should stop smoking. This may be the most important action you can take to improve your health and decrease your risk of lung cancer.

The risk of non-cancerous asbestos-related diseases generally increases with increasing levels of exposure, however, this dose-response relationship is less clear for mesothelioma, where even short-term occupational exposure, or secondary household exposure occur. Cigarette smoking has no relationship to mesothelioma. We are all exposed to asbestos in the air we breathe, however, these levels are generally considered "acceptable". There has been no correlation drawn as to why, given the same set of circumstances and amounts of exposure, one person contracts mesothelioma and the person next to them does not, or why the more heavily exposed individual never contracts an asbestos-related disease, yet his wife is diagnosed after washing his work clothing.