Reducing Your Risk

Doctors cannot always explain why one person develops lung cancer and another does not, but there are certain risk factors that research has shown increase a person’s chance of developing lung cancer.

Being a current smoker is just one of them. Of those newly diagnosed with lung cancer, it is estimated that less than 40% are current smokers, more than 49% are former smokers, and 10% to 15% have never smoked.1,2,3,4,5 Researchers are continuing to learn more about lung cancer risk factors and how to reduce them.

If you are at increased risk of developing lung cancer, talk to your doctor. He or she may be able to give you more information on these and other ways to reduce your risk, including referring you to a screening program. Read more about screening here.

The following factors can increase your risk of lung cancer. Read more, including how to reduce your risk, in the sections below.

Tobacco smoke

Tobacco smoke causes most cases of lung cancer. It is by far the most important risk factor for lung cancer. Harmful substances in smoke damage lung cells, cause mutations, and make the lungs more vulnerable to other cancer-causing environmental factors, such as asbestosA group of minerals that take the form of tiny fibers; has been used as insulation against heat and fire in buildings and radonA radioactive gas that is released by uranium, a substance found in soil and rock. Smoking cigarettes, pipes, or cigars can cause (or accelerate) lung cancer. Secondhand smoke—smoke from other people’s tobacco use—can even cause lung cancer in nonsmokers. The more and the longer a person is exposed to smoke, the greater the risk of lung cancer. It is best not to start smoking. However, even those who do smoke can significantly lower—although never eliminate even after many years of non-smoking—their risk of developing lung cancer by quitting. In addition, it is never too late to quit; there are health benefits, including longer survival and a lower likelihood of a recurrence of their lung cancer, even to those who don’t quit smoking until after a lung cancer diagnosis. There are many tobacco cessation programs to help a smoker quit; two such programs are the US government’s program at and the American Lung Association’s Freedom from Smoking® Online program.6,7,8


Radon is a radioactiveGiving off radiation gas that you cannot see, smell, or taste. It forms naturally in soil and rocks. Radon damages lung cells, and people exposed to radon are at increased risk of lung cancer. Radon is the second leading cause of lung cancer, and the risk of lung cancer from radon is even higher for smokers. People who work in mines may be exposed to radon, and radon can also be present in buildings. Because there is no way to know for sure without testing whether radon is in a building, the US Environmental Protection Agency (EPA) recommends that people test their homes for radon levels. If a high level is found, there are ways to lower it to make a home safer. For information and resources on how to protect yourself from exposure to radon, visit the radon section of the EPA's website or contact your local Department of Health.9

Asbestos and other carcinogens

People who have certain jobs (such as those who work in the construction and chemical industries) have an increased risk of lung cancer. Exposure to asbestos, arsenic, chromium, nickel, soot, tar, and other substances can cause lung cancer. The risk is highest for those with years of exposure. The risk of lung cancer from these carcinogensAny substance that causes cancer is even higher for smokers. It is important to follow all of the safety guidelines provided by your employer. It is also a good idea to check with your doctor about any additional precautions you should take if you are exposed to these substances at work.10,11

Air pollution

Air pollution, which can include diesel fumes, may increase the risk of lung cancer. The risk from air pollution is higher for smokers. Because most sources of air pollution cannot be controlled by individuals, policymakers must take steps to reduce it.12

Family or personal history of lung cancer

People with an immediate family member—father, mother, brother, sister, son, or daughter—who has had lung cancer may be at increased risk for developing lung cancer. This is particularly the case when more than one family member is or has been affected by the disease, and at an early age. The increased risk may be due to exposure to the same environmental risk factors, including tobacco smoke, or possibly, in rare cases, to an inherited mutation.6,13

People who have had lung cancer themselves are at increased risk of developing a second lung tumor.6

Radiation therapy

People who have had radiation therapy to the chest for cancers other than lung cancers have a higher risk of developing lung cancer; those with the highest risk include those who have been treated for Hodgkin disease and women with breast cancer who were treated with radiation after a mastectomy.6,14,15

Age 65 and older

More than two-thirds of people diagnosed with lung cancer are 65 years or older when diagnosed.16


Smokers who take beta-carotene supplements are more likely to develop lung cancer. Drinking water from public sources is tested to ensure that the level of arsenic is below that which could cause any adverse effects, but arsenic in drinking water from private sources, eg, wells, can increase lung cancer risk; this water should be tested.6,17

Updated January 3, 2018


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  7. What Can I Do to Reduce My Risk of Lung Cancer? Centers for Disease Control and Prevention website. Updated July 17, 2017. Accessed November 27, 2017.
  8. Former Smokers and Cancer Risk. OncoLink website. Modified March 23, 2012. Accessed November 27, 2017.
  9. A Citizen’s Guide to Radon: The Guide to Protecting Yourself and Your Family from Radon. US Environmental Protection Agency website. Revised December 2016. Accessed November27, 2017.
  10. Asbestos Exposure and Cancer Risk. National Cancer Institute website. Reviewed June 7, 2017. Accessed November 27, 2017.
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  12. Ambient (outdoor) air quality and health—Fact Sheet No. 313. World Health Organization website. Updated September 2016. Accessed November 27, 2017.
  13. Gazdar A, Robinson L, et al. Hereditary Lung Cancer Syndrome Targets Never Smokers with Germline EGFR Gene T90M Mutation. J Thorac Oncol. 2014 Apr; 9(4):456-463. doi: 10.1097/JTO.0000000000000130. Accessed November 27, 2017.
  14. Schaapveld M, Aleman B, et al. Second Cancer Risk up to 40 Years after Treatment for Hodgkin's Lymphoma. N Engl J Med 2015; 373: 2499-2511. doi: 10.1056/NEJMoa1505949. Accessed November 27, 2017.
  15. Second Cancers After Breast Cancer. American Cancer Society website. breast-cancer-survivor/second-cancers-after-breast-cancer.html. Accessed December 11, 2017.
  16. SEER Stat Fact Sheets: Lung and Bronchus Cancer. National Cancer Institute website. Updated April 2017. Accessed November 27, 2017.
  17. FAQs: Arsenic in Private Well Water. Executive Office of Energy and Environmental Affairs—Massachusetts website. Accessed November 27, 2017.