Lung Cancer and Radon: The ‘Other’ Risk Factor


Smoking is likely the first thing that comes to mind when you think about risk factors for developing lung cancer, and for good reason: Smoking is responsible for 90 percent of all lung cancers and is the leading cause of cancer-related deaths in the United States.

But smoking, it turns out, is not the only risk factor for developing lung cancer. Exposure to radon — a naturally occurring odorless, colorless and tasteless radioactive gas — largely constitutes the remaining 10 percent of lung cancer cases.  That’s an estimated 21,000 lung cancer deaths in the U.S. each year.

Radon and Its Effect on Lungs

Radon gas is a natural product of the radioactive decay of uranium in rock, soil and water. As it decays into radon gas, it moves from soil to atmosphere and enters structures, generally through their foundations, and becomes trapped and accumulates. It poses a health threat to occupants as it breaks down into minute, radioactive particles that are easily inhaled and cling to lung tissue.

Radon is a Group 1 carcinogen according to the International Agency for Research on Cancer classification of carcinogenic agents. Like nicotine, it is among those substances that undeniably cause cancer in humans. Scientists believe continual exposure to indoor radon is the greatest risk to developing lung cancer, second only to smoking.

“Not everyone exposed to radon will develop lung cancer,” explains Christina Szot, MD, pulmonologist at Renown Health, “But increased and prolonged exposure amplifies the risk.”

The American Lung Association, Environmental Protection Agency, the U.S. Surgeon General and the American Medical Association agree that exposure to radon poses a threat to individuals and families across the country. An estimated 21,000 Americans die from radon-related lung cancer each year.

Nicotine and Lung Cancer

Those with a history of smoking tobacco are still at the highest risk of developing lung cancer. According to Dr. Szot, lung function begins to decline naturally around age 30.

“In healthy people, however, the age-related changes seldom lead to respiratory symptoms,” Dr. Szot says.

But smoking, which accounts for 80 percent of lung cancer deaths, accelerates the loss of lung function. It increases the risk of heart disease, stroke and chronic obstructive pulmonary disease (COPD), often leading to disability and death at a younger age.

Breathing secondhand smoke can be just as harmful and deadly. Secondhand smoke comes from two sources: mainstream smoke exhaled by a smoker, and sidestream smoke (SHS) generated by the lighted end of a cigar, cigarette or pipe. The Centers for Disease Control and Prevention reports that any exposure to secondhand smoke puts both adults and children at risk for respiratory infections, heart disease and lung cancer. And according to the U.S. Department of Health and Human Services, secondhand smoke is responsible for 7,330 lung cancer-related deaths per year. 

Preventing Lung Cancer from Radon and Nicotine

The good news? Exposure to radon and nicotine and the subsequent health risks are preventable. You can test your home for the presence of radon with a simple, inexpensive kit. If it is detected, a licensed and board-certified mitigation specialist can install a radon mitigation system in your home to eradicate the gas as quickly as possible.

If SHS is a concern, Dr. Szot recommends decreasing your exposure by avoiding indoor areas where smoking is allowed. And if you have a smoker at home, enforce a smoking outdoors-only rule. If you’re a smoker, quitting is the challenging but necessary solution. For assistance with smoking cessation, visit Renown’s Quit Tobacco Program.

RELATED:  World No Tobacco Day: Dangers of Smoking and Benefits of Quitting

Free Radon Test Kits for Nevada Residents

The Nevada Radon Education Program is a partnership with the Nevada Division of Public and Behavioral Health to educate Nevadans about the health risk posed by elevated levels of radon in the home. The Extension program offers literature, educational presentations and low-cost test kits in many county Extension and partner offices.

Thanks to the Nevada Radon Education Program, Nevada residents can get a free test kit during National Radon Action Month, January 1 – February 29, 2020.

Nevada Radon Education Program


  1. I had my home tested using the free kits (3) and ALL were above the EPA limit. So this year I had a radon mitigation company complete the install of a mitigation system. I used a USDA Rural Development loan to pay for the repairs. Have your home tested, it is worth it since the kits are free!
  2. Is this a 3 hour class, or can we drop by and pick up the kit? Is the Institute reached by the Mill St. parking garage? Thank you!
    • Hello Marilyn, The event features a booth with information and free kits; stop by anytime between 7 a.m. and 10 a.m. at the Starbucks at Renown Regional. I recommend parking at the Second Street garage. In good health, Roseann
  3. As a child of both of my parents passing away from Lung Cancer, this means so much to me. I pray for a cure to all cancers. I stopped smoking in June of 2015 and have enjoyed not smoking.