Mesothelioma is an aggressive and rare form of cancer that targets the lining of organs including the lungs, chest, and abdomen. Mesothelioma can almost always be traced to one risk factor; exposure to asbestos. Asbestos is a natural fiber that was a popular element filling U.S homes and businesses in the late 19th century and became more widespread after World War II. Asbestos continued to be used in the 1970’s. Once asbestos is inhaled, it cannot be exhaled; it lingers in the lungs. With most patients this triggers mesothelioma 15+ years after exposure.