Why Nonsmokers Get Lung Cancer

January 2023

Lung cancer is the top cause of U.S. cancer deaths, claiming more lives than breast, colon, and prostate cancers combined. While cigarette smoking is the top risk factor for the disease, nonsmokers can be diagnosed, too. Learning about less common causes of lung cancer may help you avoid them.

Radon

Radon is a radioactive gas that can enter homes through cracks in floors and foundations. Radon can also come from 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 nonsmokers. To reduce your family’s risk for radon-related lung cancer, the Environmental Protection Agency recommends testing your home for radon.

Secondhand smoke

Nonsmokers who inhale secondhand smoke take in nicotine and toxic chemicals, more than 70 of which can cause cancer. In the U.S., exposure to secondhand smoke is responsible for about 7,300 deaths from lung cancer and close to 34,000 deaths from heart disease every year.

Nonsmokers can face secondhand smoke at work; in public places such as parks, outdoor shopping areas, and some restaurants and bars; in their homes; and in cars, where hazardous levels of smoke can build up quickly. Your best protection: avoiding secondhand smoke.

Asbestos

Asbestos increases the risk for lung cancer and other lung diseases. Resistant to fire and heat, this group of minerals was once widely used in industry and 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 employer.

Family history

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

Lung cancer is a frightening diagnosis that no one deserves. To reduce your risk for the disease, control your risk factors. If you’re a smoker or former smoker older than age 50, ask your healthcare provider if you should have a CT scan to screen for the disease.