Radon is a colorless, tasteless and odorless gas that causes lung cancer. Exposure to radon is the second leading cause of lung cancer in the United States, after smoking. Radon-related lung cancers result in an estimated 21,000 deaths annually in the United States.
Radon forms naturally. Uranium in soil or rock breaks down to form radium, which then turns into radon gas. Once formed, radon enters a building through cracks in walls, basement floors, foundations and other openings. As radon decays, it releases radioactive byproducts that are inhaled and can cause lung cancer. Because radon comes from rock and soil, it can be found anywhere. Being exposed to limited amounts, like those found outdoors, is impossible to avoid. However, when radon gets trapped indoors, it may exist in dangerous at dangerous amounts.
Less often, radon may enter buildings from water used in bathroom showers and faucets. Concerns have also been raised about the radon released indoors from building materials, such as granite counter tops or tiles. However, these sources have rarely proven to be a problem.
Radon is the second leading cause of lung cancer in the United States, responsible for thousands of deaths each year. Exposure to radon causes no immediate symptoms, but the long-term threat of lung cancer is important to everyone. People who have never smoked make up one out of 7 radon-related lung cancer deaths each year.
The health hazard comes from radioactive particles released when radon decays. These particles can be inhaled into the lung and attack your cells with dangerous, cancer-causing radiation. Smoking and radon exposure can separately increase the risk of lung cancer. But if you smoke, know that exposure to both greatly enhances the risk of lung cancer.
Every home should be tested for radon. Radon has been found in high amounts in homes in every state. Your home can have elevated levels of radon while your neighbor's home does not. Testing is the only way to know if radon is a problem in your home. Radon testing is easy and low cost, and it could save your life. Thousands of lung cancer deaths could be avoided each year if home and building owners acted to test and fix.
The only way to detect a buildup of radon in your home is to test the air. Do-it-yourself test kits and digital detectors are simple to use and low in cost.
Short-term tests usually take two to seven days. To use a short-term radon test, place the kit in the lowest level regularly used in your home and where it will not be disturbed. Follow the test directions and other guidance to prevent problems that can affect the testing. Once the testing period is complete, seal the test kit and send it to a laboratory for analysis. Most test kits include the cost of lab analysis. In a matter of weeks, you will be told of the radon level in your home.
Long-term tests tend to be more accurate because they collect more data. Long-term radon tests take at least three months and measure long-term averages. If you do not want to wait for a long-term test, short-term tests can tell if your home has a problem and requires follow-up testing. Order a radon test kit today.
Digital detectors can be purchased for your home and can provide short-term readings and report an average for the long term.
If you prefer, hire a certified radon-testing professional. The best way to find a certified professional is to contact your state radon program.
Radon gas is measured in picocuries per liter (pCi/L) of air. The EPA recommends taking action to reduce radon if the result is 4.0 pCi/L or greater and to consider similar actions when the radon level is between 2 and 4.0 pCi/L. The goal is to get your radon level to the lowest level possible.
There are several ways to protect you and your family from the dangers of radon gas.
If you have an existing home with elevated levels of radon, you can fix the problem by having a radon mitigation system installed. A radon mitigation system consists of a vent pipe, fan and the sealing of cracks in in the baseline floor and foundation. This system collects radon gas from underneath the foundation and vents it to the outside of your home. If you need to have a radon mitigation system installed, it is best to hire a certified radon mitigation professional. Contact your state radon program for a list of certified radon mitigation professionals.
If you are building a new home, ask your contractor to install radon-resistant features. These features include gravel and plastic sheeting below the foundation, sealing of cracks and the installation of a vent pipe. Once the radon-resistant features have been installed and the home is completely built, make sure to perform a radon test, as the levels could still be elevated. If the radon levels are still elevated, a radon fan should be added to the system to lower the radon level.
Detailed information about radon reduction in your home or building can be found in EPA's Consumer's Guide to Radon Reduction.
The American Lung Association is working with national partners and government agencies to build in ways to reduce radon in all homes. The National Radon Action Plan outlines strategies to protect millions more people from dangerous radon exposure.
Radon Action Plan
Radon Resources for Professionals
Order a Radon Test Kit
Page last updated: November 17, 2022