Asbestos is a naturally occurring mineral that has had many commercial uses
during the last century, so it can be found in many building materials and other
objects. Excessive exposure through inhalation can result in asbestosis, lung
cancer, or mesothelioma (another kind of cancer). Asbestos seems to produce
cancer through the physical interaction of its fibrous structure with living
cells. Radon is a naturally occurring radioactive gas with no significant commercial application. Excessive exposure through inhalation can result in lung cancer. Radon produces cancer because it emits ionizing radiation which in turn produces cancer upon sufficient exposure.