Lung cancer kills nearly 160,000 people in the United States each year, and remains the leading cause of cancer deaths, the American Cancer Society (ACS) states. Lung cancer has one of the lowest survival rates of all cancers, with between 11 and 15 percent of patients surviving 5 years. The risk of developing lung cancer is approximately 1 in 13 for men and 1 in 16 for women overall; the risk for smokers is much higher, says the Mayo Clinic. While the risk proves much lower for non-smokers, they can and do develop lung cancer from several causes.
Radon Gas
Radon gas exposure causes the largest number of lung cancer cases in non-smokers, the Environmental Protection Agency (EPA) reports, and causes around 2,900 deaths each year in non-smokers in the U.S. Radon, an odorless, tasteless gas, which occurs from the breakdown of uranium in rock, water and soil, can accumulate in buildings, including homes. Radon accumulation is worse in rooms below grade level, such as basements.
The average radon concentration in American homes is 1.3 pCi/L(pico Curies per Liter); if exposed to this radon concentration, the EPA estimates that 2 out of 1,000 nonsmokers would develop lung cancer, compared to 7 out of 1,000 nonsmokers at 4 pCi/L. The EPA recommends that a house be fixed if the level exceeds 4 pCi/L. Occupations at highest risk for radon exposure include miners and other jobs where people work underground, such as in tunnels or caves.
Secondhand Smoke
Secondhand smoke causes approximately 3,000 deaths from lung cancer in non-smokers. Secondhand smoke at home or work increases the risk of developing lung cancer by 20 to 30 percent, the 2006 Surgeon General's report warns. Separate smoking and non-smoking areas in a building, air filters and ventilation do not remove all secondhand smoke from the air, the report adds.
Asbestos and Other Chemical Exposure
Exposure to chemicals such as asbestos, arsenic, chromium, nickel and tar increase the chances of developing lung cancer in non-smokers, according to the Mayo Clinic. Exposure to asbestos fibers can increase the chance of developing lung cancer up to 5 times, Princeton University reports. A rare form of cancer that develops in the lining of the lungs, called mesothelioma, occurs almost exclusively in people exposed to asbestos.
