Does Radon Exposure Cause Lung Cancer?
Smoking is the biggest cause of lung cancer -- but it's not the only one. According to the Environmental Protection Agency, exposure to radon is the second leading risk factor for lung cancer and the No. 1 cause of lung cancer among non-smokers. The World Health Organization says radon causes up to 14 percent of lung cancer deaths worldwide, and in the U.S., about 21,000 lung cancer deaths per year are due to radon. Of those, about 2,900 occur in people who never smoked.
What Is Radon?
Radon is a radioactive gas. You can't see it or smell it, and it's possible you're exposed to radon and don't realize it. Radon is released when uranium and thorium break down. These naturally occurring chemical elements are found in rocks and the soil. Radon can seep up into your house through cracks and diffuse into the air.
[See: 7 Things You Didn't Know About Lung Cancer.]
How Much Does Radon Raise the Risk for Lung Cancer?
According to the EPA, radon gas decays into radioactive particles. These particles can get trapped in your lungs when you breathe and continue to break down, releasing small bursts of energy that can damage lung tissue and, over many years, lead to lung cancer. "High levels of radon contribute to the risk for lung cancer. We're just not sure how much," says Dr. Leena Gandhi, director of thoracic medical oncology at the Perlmutter Cancer Center at NYU Langone Medical Center.
The risk for radon-induced lung cancer is substantially higher in smokers. In fact, about 86 percent of radon-related lung cancer deaths occur in current or former smokers, and the WHO estimates smokers are 25 times more at risk from radon than non-smokers.
Many people in the U.S. live in areas where radon is abundant, and approximately 1 in 15 homes has levels of radon above the EPA's action level of 4 picoCuries per liter, or pCi/L, of air. Ideally, levels should be even lower, as there's no safe level of exposure to radon. You're more likely to have trapped radon if your home is well-insulated or tightly sealed.
According to the EPA, if 1,000 people who smoked were exposed to 4 pCi/L of radon over a lifetime, about 62 might develop lung cancer. To put this in context, it's five times the risk of dying in a car crash. In contrast, only about seven non-smokers would develop lung cancer at the same exposure.
In January 2005, the U.S. Surgeon General released a National Health Advisory on radon and said that radon gas in indoor residential structures poses a serious health risk.
[See: What Not to Say to Someone With Lung Cancer.]
Lowering the Risk
Fortunately, it's possible to lower your risk of exposure. The first step is to test your house for radon. Although some areas of the country have higher levels of radon than others, radon is present nationwide. It doesn't matter if you have an old house or a new one, an expensive home or an inexpensive home. Radon does not discriminate. Even if your neighbor's house tests negative for radon, it doesn't mean yours will. The EPA and the Surgeon General recommend that all homeowners test each floor of their home up to the third floor.
You can purchase an inexpensive radon test kit at your local hardware store. Or, you can order a test through an online retailer, the National Radon Program Services at Kansas State University or the American Lung Association. You can also hire a professional tester.
If your house tests positive for radon, you'll want to reduce the level to lower your exposure. There are several ways to do this, but the most common radon mitigation system is a vent pipe system and fan, which removes the radon from your house.
The National Cancer Institute estimates that we could reduce lung cancer deaths by 2 to 4 percent annually (about 5,000 deaths) by lowering radon levels in homes exceeding 4 pCi/L. "Rates of radon testing are low, especially in multi-generational homes," says Dr. Vamsidhar Velcheti, a medical oncologist at Cleveland Clinic. "Radon levels in a house are not static. It's all about the circulation in your home." Just because your family has been living in your home for a long time doesn't mean your house doesn't have radon. Test it.
The Environmental Protection Agency has a wealth of resources about radon on its website. Start with A Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family from Radon.
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If you won't test your home for yourself, do it for your children. "The folks at higher risk are the youngest," Velcheti says. "They are more prone to the carcinogenic effects [of radon]. They have more cells dividing in their body." Cancer takes decades to develop, Velcheti says. Exposure to radon at a young age could put someone at risk for lung cancer many years later.
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