Stacy Simon, American Cancer Society – “Most people know that smoking causes cancer, but may not realize how many nonsmokers get lung cancer, too. Every year, about 16,000 to 24,000 Americans die of lung cancer, even though they have never smoked. In fact, if lung cancer in nonsmokers had its own separate category, it would rank among the top 10 fatal cancers in the United States. Unfortunately, a perception that patients contributed to their own illness by smoking harms both smokers and nonsmokers with lung cancer…[but] researchers have made a lot of progress over the past decade in understanding some of the causes of lung cancer in nonsmokers and how to treat it.

• Radon gas. The leading cause of lung cancer in nonsmokers according to the US Environmental Protection Agency (EPA) is exposure to radon gas. It accounts for about 20,000 deaths from lung cancer each year. Radon occurs naturally outdoors in harmless amounts, but sometimes becomes concentrated in homes built on soil with natural uranium deposits. Studies have found that the risk of lung cancer is higher in those who have lived for many years in a radon-contaminated house. Because radon gas can’t be seen or smelled, the only way to know whether it’s a problem in your home is to test for it. A Citizen’s Guide to Radon, produced by the EPA, explains how to test your home for radon easily and inexpensively, as well as what to do if your levels are too high.
• Secondhand smoke. Each year, an estimated 3,400 nonsmoking adults die of lung cancer as a result of breathing secondhand smoke. Laws that ban smoking in public places have helped to reduce this danger. The American Cancer Society Cancer Action Network (ACS CAN), the nonprofit, nonpartisan advocacy affiliate of the American Cancer Society, is working to expand and strengthen these laws to further protect both smokers and nonsmokers from the dangers of secondhand smoke.
• Cancer-causing agents at work. For some people, the workplace is a source of exposure to carcinogens like asbestos and diesel exhaust. Work-related exposure to such cancer-causing materials has decreased in recent years, as the government and industry have taken steps to help protect workers. But the dangers are still present, and if you work around these agents, you should be careful to limit your exposure whenever possible.
• Air pollution. It’s long been known that both indoor and outdoor air pollution contribute to lung cancer. In October 2013, the International Agency for Research on Cancer (IARC), part of the World Health Organization, classified outdoor air pollution as a cancer-causing agent. The IARC evaluated more than 1,000 studies and concluded that increased exposure to outdoor air pollution increases the risk of lung cancer…”