Lung Cancer Risks for Non-smokers

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As many as 20% of people who die from lung cancer in the United States every year have never smoked or used any other form of tobacco. In fact, if lung cancer in non-smokers had its own separate category, it would rank among the top 10 fatal cancers in the United States.

Lung cancer happens because cells in the lung mutate or change. Most often those changes happen from breathing in harmful chemicals in the air. While it’s true that staying away from tobacco is the most important thing any of us can do to lower our risk of getting lung cancer, there are also other risk factors. And some people who get lung cancer have no known risk factors.

Researchers continue to make progress in understanding what can cause lung cancer in people who have never used tobacco:

  • Radon gas. The leading cause of lung cancer in non-smokers is exposure to radon gas, according to the US Environmental Protection Agency (EPA). It accounts for about 21,000 deaths from lung cancer each year.  About 2,900 of these deaths happen among people who never smoked. 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 people 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 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, about 7,000 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 NetworkSM (ACS CAN) - the nonprofit, nonpartisan advocacy affiliate of the American Cancer Society - is working to expand and strengthen these laws to further protect both people who smoke and those who don't from the dangers of secondhand smoke.
  • Cancer-causing agents at work. Some people are exposed to carcinogens (cancer-causing agents) such as arsenic, asbestos and diesel exhaust at their workplace. Work-related exposure to such cancer-causing materials has decreased as the government and industry have taken steps to help protect workers. Still, if you work around these agents, be careful to limit your exposure whenever possible.
  • Air pollution. Researchers have known for a long time that both indoor and outdoor air pollution can contribute to lung cancer. The World Health Organization (WHO) classifies outdoor air pollution as a carcinogen. However, it's believed the risk of lung cancer associated with air pollution is lower in the US than in many other countries because of policies that have helped to lower the levels of exposure.
  • Gene mutations. Researchers are learning more about what causes cells to become cancerous, and how lung cancer cells differ between people who have never smoked and those who smoke. Understanding how gene changes cause lung cancer cells to grow has helped researchers develop targeted therapies, drugs that specifically attack cells with these mutations.

Lifestyle changes to lower risk

Non-smokers avoid the greatest risk factor for lung cancer. But they can make some lifestyle changes to help reduce their risk even more.

In addition to testing your home for radon, avoiding secondhand smoke, and limiting exposures to carcinogens at work , eating a healthy diet with lots of fruits and vegetables may also help reduce your risk of lung cancer. Some evidence suggests that a diet high in fruits and vegetables may help protect against lung cancer in people who smoke and non-smokers. 

 

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.


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