Asbestos is a mineral found in certain types of rocks formations. When it is mined and processed, it takes on the form of very small fibers, smaller than the human eye can see. Asbestos remains in the air for many hours once it is released, which makes the likelihood of inhalation very high. Asbestos in the lungs causes two distinct illnesses: asbestosis, a scarring of the lung tissues, and mesothelioma, a deadly lung cancer. Nearly 100 percent of mesothelioma patients were exposed to asbestos on a regular basis, such as at work. In addition, exposure to asbestos has been linked with other cancers, often occurring years after the exposure. All of the diseases related with asbestos in the lungs can have a long latency period, but are extremely dangerous. Most patients with mesothelioma die within 12 months of their diagnosis. The scarring associated with asbestosis can be so severe that the lungs eventually cannot function.