People who smoke cigarettes are 15 to 30 times more likely to contract lung cancer compared to nonsmokers, according to the Centers for Disease Control and Prevention. As of 2015, 90 percent of lung cancer cases are linked to cigarette smoking. Cigar and pipe smokers also are at increased risk.
People exposed to second-hand smoke also are at an increased risk for lung cancer, according to the CDC. Exposure to radon, a gas naturally occurring from dirt and rocks and sometimes found in homes, can increase the risk as well. Radon exposure causes approximately 20,000 cases of lung cancer every year.
Research studies as of 2015 indicate that men are more likely to develop lung cancer than women, and the most common ethnic group to develop lung cancer is African Americans, according to the American Lung Association. African-American men develop lung cancer at 32 percent higher rate than white men, but African-American women and white women have the same risk. Lung cancer is the leading terminal cancer for both genders.
Additional risk factors for lung cancer include exposure to arsenic, diesel exhaust, silica, chromium, asbestos and previous chest radiation therapy for cancer, according to the CDC. A personal history or family history of lung cancer increases the risk of an individual developing another kind of cancer.