Buying a New Home? How to Protect Your Family from Radon

  • What is Radon?

Radon causes an estimated 14,000 lung cancer deaths each year. It is the earth's only naturally produced radioactive gas and comes from the breakdown of uranium in soil, rock, and water. You cannot see or smell radon, but it can become a health hazard when it accumulates indoors. It can enter your home through cracks and openings in the foundation floor and walls. When radon decays and is inhaled into the lungs, it releases energy that can damage the DNA in sensitive lung tissue and cause cancer.

Radon is a naturally-occurring radioactive gas that may cause cancer, and may be found in drinking water and indoor air. Some people who are exposed to radon in drinking water may have increased risk of getting cancer over the course of their lifetime, especially lung cancer. Radon in soil under homes is the biggest source of radon in indoor air, and presents a greater risk of lung cancer than radon in drinking water. As required by the Safe Drinking Water Act, EPA has developed a proposed regulation to reduce radon in drinking water that has a multimedia mitigation option to reduce radon in indoor air.

  Radon (chemical symbol Rn) has numerous different isotopes, but radon-220, and -222 are the most common. Radon causes lung cancer, and is a threat to health because it tends to collect in homes, sometimes to very high concentrations. As a result, radon is the largest source of exposure to naturally occurring radiation.

  • Why Buy a Radon-Resistant Home?
  • The Techniques Work - Simple and inexpensive techniques reduce radon levels on average by 50%. The techniques may also lower levels of other soil gases and decrease moisture problems.

  • It's Cost Effective - Building in the features is much cheaper than fixing a radon problem later.

  • Save Energy - Radon-reduction techniques are consistent with state-of-the-art energy-efficient construction.  When using these techniques, follow the Model Energy Code (or other applicable energy codes) for weatherization, which will result in energy savings and lower utility bills.

  • Upgrading is Easy - If high levels of radon are found, a fan can easily be installed as part of the system for further radon reduction.

  • How Do Costs Compare?
  • Average cost to install radon-resistant features in an existing home: $800 - $2,500

  • Average cost to install radon-resistant features during new home construction: $350 - $500


  • What are Radon-Resistant Features?

The techniques may vary for different foundations and site requirements, but the basic elements are shows in Figure 172.

Figure 172: Some Radon-Resistant Features For Homes

A. Gas Permeable Layer

This layer is placed beneath the slab or flooring system to allow the soil gas to move freely underneath the house. In many cases, the material used is a 4-inch layer of clean gravel.

house cutaway

B. Plastic Sheeting

Plastic sheeting is placed on top of the gas permeable layer and under the slab to help prevent the soil gas from entering the home. In crawlspaces, the sheeting is placed over the crawlspace floor.

C. Sealing and Caulking

All openings in the concrete foundation floor are sealed to reduce soil gas entry into the home.

D. Vent Pipe

A 3- or 4-inch gas-tight or PVC pipe (commonly used for plumbing) runs from the gas permeable layer through the house to the roof to safely vent radon and other soil gases above the house.

E. Junction Box

An electrical junction box is installed in case an electric venting fan is needed later.

  • Did You Know?
  • Radon is the second leading cause of lung cancer after smoking.

  • High radon levels have been found in every State.

  • Levels can vary widely, even from home to home in the same neighborhood.

  • Radon levels can be lowered, and homes can be built radon-resistant.

  • What Can You Do?

Simple, inexpensive techniques can be used to lower radon levels and increase energy efficiency in your new home. Here are basic steps to follow when buying a new home.

  1. Check Your Area's Radon Potential - Find out if you are buying a home in a high radon area. The Environmental Protection Agency's map of radon zones Figure 168: EPA Map of Radon Zones shows which areas have the greatest potential for elevated indoor radon readings. Homes in places with high radon potential, called Zone 1 areas, should be built with radon-resistant features.

  2. Install a Radon Reduction System - Talk to your builder about installing a radon reduction system. You can obtain free copies of the EPA's Model Standards and architectural drawings and use them to explain the techniques to your builder. Let your builder know that the radon resistant features can be easily installed with common building practices and materials.

  3. Remember: Test Your Home - Every new home should be tested for radon after occupancy. Test your home even if it has the radon resistant features. Test kits are inexpensive and may be purchased at your local hardware store. Or simply call the National Safety Council Radon Hotline at (800) SOS-RADON to order a test kit.

  4. If Radon Levels Are Still High, Activate - If your home tests at 4.0 picoCuries per liter (pCi/L) or above, activate the system by installing an in-line fan. Call a local radon mitigator about installing the fan. Call your State radon office for a list of radon device companies that have met State requirements.

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