Why Nonsmokers Get Lung Cancer

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The American Cancer Society estimates there will be about 228,000 new cases of lung cancer diagnosed in 2019. And while most will involve smokers, some will not.

It may seem illogical, but research shows that three out of four lung cancer cases occur in people who have stopped smoking or never smoked. Learning about the less-common causes of lung cancer may help you avoid them — and better understand the complex factors that can lead to this disease.


The decay of uranium in soil releases radon, a radioactive gas that can enter homes through cracks in floors and foundations. Radon can also come from building materials or water from wells that contain the gas. When inhaled, radioactive particles given off by radon can damage cells that line the lungs, causing cancer.

Radon exposure is the leading cause of lung cancer in non-smokers. The Environmental Protection Agency (EPA) blames radon for about 20,000 lung cancer deaths a year.

To reduce your family’s risk for radon-related lung cancer, the EPA recommends you have your home tested for radon. Take steps to control radon if the test finds a radon level of 4 pCi/L or more. For more information on radon, including how to get your home tested, visit the EPA website.

Secondhand Smoke

Non-smokers who inhale secondhand smoke take in nicotine and toxic chemicals that can cause cancer. In the U.S., exposure to secondhand smoke is responsible for about 7,300 deaths from lung cancer every year.

Non-smokers can face secondhand smoke at work; in public places such as restaurants, bars, and shopping areas; in their homes; and in cars, where hazardous levels of smoke can build up quickly. Your best protection: avoiding secondhand smoke and encouraging loved ones to quit.


Asbestos increases the risk of lung cancer and other deadly lung diseases. Resistant to fire and heat, this group of minerals was once widely used in construction. People can encounter this carcinogen at work, in their communities and at home. However, people who develop serious illnesses most often had contact with asbestos on the job.

If you’re worried about your potential exposure to asbestos, discuss your concerns with your employee health and safety representative and your employer. For information about asbestos and lung cancer, visit the website of the Occupational Safety and Health Administration.

Family History

People also have an increased risk of lung cancer if their parents or siblings have had the disease. The increased risk could come from sharing behaviors such as smoking, living together in a house that contains radon, or inheriting a gene that makes them prone to the disease.

Lung cancer is a difficult diagnosis we hope you never have to face. To reduce your risk for the disease, control your risk factors. If you’re a smoker or former smoker older than 55, ask your doctor if you should have a CT scan to screen for the disease.

To learn more about AdventHealth’s lung cancer care and services, visit our website.

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