How likely are you to develop lung cancer if you aren’t a smoker? It’s possible. Here are five changes you can make that may help.

Story by: Sara Thompson; Reviewed by Basel M. Altoos, M.D., radiation oncologist, Norton Cancer Institute on March 5, 2024

According to the American Cancer Society, lung cancer, including both small cell lung cancer and non-small cell lung cancer, is the second most common cancer in adults in the United States (not counting skin cancer). There will be about 234,580 new cases of lung cancer diagnosed in 2024. Of those new cases, about 10% to 20% will occur in people who have never smoked.          

Studies have confirmed that cigarette smoking causes cancer. It is linked to about 80% to 90% of lung cancer deaths in the United States.

“We know smoking causes lung cancer,” said Basel M. Altoos, M.D., radiation oncologist with Norton Cancer Institute. “Cigarettes have around 7,000 chemicals in them, and many are known to cause cancer.” 

When you inhale tobacco smoke or other cancer-causing substances, lung cells become damaged. This can happen even if you are not a smoker yourself. Over time, the damaged lung cells can’t repair themselves, and it can lead to many health issues, including some types of cancer and heart disease.

But can you get lung cancer without smoking? Is that possible? The short answer is yes.

Risk factors for lung cancer without smoking

These factors are strongly linked to lung cancer in people who have never smoked.

“People might not understand their lung cancer risk if they have never smoked,” Dr. Altoos said.

Secondhand smoke: It causes around 7,300 deaths from lung cancer in nonsmokers every year. It’s also linked to other cancers, stroke, heart disease and asthma. Secondhand smoke also negatively affects other adults, children and pets. Secondhand smoke can come from being near someone smoking cigarettes, cigars, pipes or hookahs. Even short-term exposure to secondhand smoke can be bad for your health. 

You can be exposed to secondhand smoke at home, in the workplace or in public spaces such as bars. This can be tobacco smoke, or the vapors from electronic cigarettes or other smoke sources. Many states have specific bans on smoking in certain places, such as government buildings and health care facilities. 

Radiation therapy: If you have had past radiation to the chest for another type of cancer, it can increase your risk of developing lung cancer.

Radon exposure: Radon is a naturally occurring gas. It comes from the breakdown of uranium in soil, rock and water. The gas becomes part of the air you breathe. Unsafe levels of radon can accumulate in any building, including homes. This can increase your chances of lung cancer. Radon gas exposure causes about 21,000 cases of lung cancer death in the United States every year. 

Exposure to asbestos and other carcinogens: Exposure to asbestos and other substances known to cause cancer — such as arsenic, chromium and nickel — can increase your risk of developing lung cancer, especially if you’re a smoker.

Air pollution: In a similar way, long-term exposure to water and air pollution can impact your chances of developing lung cancer.

Family history of lung cancer: If you have a parent, sibling or child with lung cancer, you may have an increased risk of the disease.

5 ways to reduce your risk of developing lung cancer if you don’t smoke

1. Limit smoking in your home. There is no safe level of secondhand smoke, and the best way to protect yourself is to keep smoke out of your environment. Invite smokers to go outside if they wish to smoke at your home or office. Do not allow smoking in your vehicle.  
2. When you go out, visit tobacco-free restaurants and other public spaces, and avoid those that allow smoking.
3. If your employer doesn’t offer a smoke-free environment, talk to them about the benefits of a smoke-free workplace.
4. Have your home tested for radon. This gas can get into your house through cracks in floors, walls or the foundation. Levels of radon can build up over time. 
5. Limit exposure to carcinogens (cancer-causing substances) such as arsenic, asbestos, nickel, chromium and lead.

Talk to your health care provider if you have a family history of lung cancer. This puts you at higher risk for developing the disease. You can’t change your genes, but you may be able to reduce your risk. You may need to have an annual lung cancer screening.

Signs of lung cancer often don’t develop until the cancer is advanced. See your doctor if you are coughing up blood, have a cough that won’t go away or other lung cancer symptoms.

If you smoke, you are at an increased risk of developing lung cancer.  Consider quitting smoking — for your own health and for the health of your family, friends and pets.