Colorectal cancer is the second leading cause of cancer death in the United States after lung cancer.

For example, indoor radon exposure was estimated to cause between 3-14 % of all lung cancers in 2004, the second most important cause of lung cancer in many countries.

While asbestos exposure is a causative factor for both disorders, it is the only known cause of mesothelioma while lung cancer can be caused by other agents-including cigarette smoking.