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Radon - Frequently Asked Questions

What is radon?

Radon is a colorless, odorless and tasteless radioactive gas.

Why is radon a public health concern?

Radon gas decays into particles that are inhaled and damage lung tissue. At high concentrations and over a long time period the damage can cause lung cancer. See Radon: General Information to learn more about radon.

Who is at risk?

People exposed to high levels of radon over a long period of time face an increased risk of lung cancer. Smoking in combination with long-term radon exposure increases the risk of developing lung cancer up to 10 times greater than radon exposure alone.

While some homes may be suspected to have higher risk for radon levels above 4 pCi/L based on where they are located in the EPA radon potential zones, all homes have the potential to exceed the EPA radon action level. Other factors that can impact radon levels within a home are local geology, construction materials and the way the house was built.

The following fact sheets can help you learn more about radon risks in homes and schools or child care programs.

Healthcare providers have an important role to play in educating patients. Read Radon Information for Healthcare Providers for more about radon and steps you can take to encourage testing in homes.

How do I test my home for radon?

The only way to determine the concentration of radon in your home is to do a radon test.

The EPA recommends taking a short-term test followed by a second short- or long-term test if the results from the first test are equal to or greater than 4 pCi/L. If the short-term test result is more than twice the EPA action guideline of 4pCi/L, the second, confirmatory test should be a short-term test, and it should be done immediately. Results from the second round of testing should be used to confirm the need for radon mitigation.

Test kits will come with specific instructions, but generally they will need to be placed in the lowest utilized part of the house. Tests should be conducted during the heating season since the highest levels of radon typically occur during the winter. If living patterns in the house change and a lower level of the home is used, the home should be retested on that level. The test device will be left in place for a designated amount of time, from 2 days to up to 90 days for short-term tests, and then repackaged and sent to a certified lab for analysis. For a short-term test, windows on all levels and all outside doors should be left closed for the entire test period (called “closed building conditions”). For a test period lasting less than 4 days, closed building conditions must be maintained for at least 12 hours prior to beginning the test and for the duration of the test.

For more detailed information about testing your home for radon, refer to the Testing your Home for Radon fact sheet or call the Radon Hotline at (800) 723-6695  for more information. The EPA also provides two online resources that may be helpful: A Citizen's Guide to Radon and the Home Buyer's and Seller's Guide to Radon.

How can the risk be reduced?

If radon levels in your home are confirmed to be above the EPA's action level a mitigation system should be installed. Mitigation systems work to redirect radon gas and vent it away from the house. See the Fixing Radon in Your Home fact sheet to learn more about mitigation. To find a contractor in Massachusetts who can install a radon mitigation system, call the Radon Hotline at (800) 723-6695 or visit the websites of the American Association of Radon Scientists and Technologists (AARST),  and the National Radon Safety Board (NRSB). These two organizations certify radon measurement and mitigation professionals.

If you are a smoker, your risk of developing lung cancer from long-term radon exposure is almost 10 times higher than someone who has never smoked. Visit the MA Tobacco Cessation and Prevention Program website or call the Smoker's Helpline at 1-800-QUITNOW to receive more information on quitting smoking.

How is radon tracked?

Radon testing is not required in Massachusetts and there is no legislation at the state or federal level for radon. However, all homeowners are encouraged to test. If you would like more information about radon in Massachusetts, contact the Radon Assessment Unit :

  • Massachusetts Department of Public Health
  • Bureau of Climate and Environmental Health
  • Indoor Air Quality Program/Radon Assessment Unit
  • 23 Service Center Road
  • Northampton, MA 01060
  • (800) 723-6695 (toll-free in Massachusetts only)
  • (413) 586-7525 x 3185
  • TTY: (800)-769-9991
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