Radon

Many factors contribute to radon entering a home. Neighboring homes can have significantly different radon levels from one another. Here are some factors that impact radon levels in a home:

• Concentration of radon in the soil and permeability of the soil under the home
• Structure and construction of the home
• Type, operation and maintenance of the home's heating, ventilation and air-conditioning (HVAC) system

You can see the results of radon tests in your town or how the bedrock geology of Vermont relates to radon risk. View the Radon Risk in Vermont maps

Everyone is exposed to some radon in indoor and outdoor air. Radon decays into radioactive particles that can damage your lungs.Breathing in radon increases your risk of getting lung cancer over the course of your lifetime. Radon is the leading cause of lung cancer among people who don’t smoke. Your risk of getting lung cancer from radon depends on the level of radon in the air you breathe, how long you are exposed to radon, and whether you smoke.

If you smoke and your home has high levels of radon, your risk of getting lung cancer is especially high. The Environmental Protection Agency (EPA) estimates that 86% of radon-related, lung-cancer deaths occur among current or former smokers. Learn more about radon, smoking and lung cancer

Vermont law does not require a radon test as part of a real estate transaction. For real estate transactions or other cases where a quick test is needed, the Health Department Lab, private labs, and building supply stores sell short-term radon test kits. Fill out an online form to request a kit from the Lab.

Short-term testing may be done in the basement if the buyer plans to use it as a living space. If you are using short-term test kits, the EPA recommends using two testing devices, placed side by side. See the EPA’s Home Buyer’s and Seller’s Guide to Radon for more information.

Radon, which is measured in units of picocuries per liter (pCi/L) of air, can be found both inside and outside your home. In Vermont, the average radon level in the outside air is 0.4 pCi/L and the average level in homes is about 2.5 pCi/L.

The action level for radon is 4.0 pCi/L. This means thatif your test result is at or above 4.0 (pCi/L), the Health Department and EPA recommend reducing radon levels in your home. However, radon levels below 4.0 pCi/L still pose some risk, so the Health Department and EPA encourage taking action to lower radon levels below 2.0 pCi/L. Contact a certified radon mitigation contractor to help you. Most radon mitigation systems can reduce radon levels in a home to 2.0 pCi/L or lower. Read the next question for more details about how to fix a radon problem.

If you have tested both your indoor air and your water for radon, using the Radon Contribution Calculator may help you estimate how much of the radon in air is due to radon in the water supply and how much is due to air entering the home through the foundation.

Radon in air problems can be fixed. There are two types of mitigation systems that can be installed. After the mitigation system is installed, test for radon again to make sure levels are below 4.0 pCi/L.

Active soil depressurization (ASD)

An ASD is a very common system. It can be installed in many homes with varying foundation types. In most cases, this system involves installing a vent pipe and a fan to reduce radon entry into the home. 

Heat recovery ventilator or energy recovery ventilator (HRV or ERV)

HRVs and ERVs exhaust air from a home and replace it with fresh outdoor air. Because supplying too much outdoor air can impact comfort and increase energy use, HRVs and ERVs are best used for moderate radon levels or to supplement an ASD system. HRVs and ERVs can also improve the air quality inside a home. 

You can search for a certified radon in air mitigation contractor at nrpp.info/pro-search or nrsb.org/find-a-pro.

Fact sheet: Fixing Radon in Your Home

There are programs to help eligible Vermonters fix health and safety problems in their homes, including radon problems.

Read about the available programs to see if you qualify

Building your new home using certain materials and techniques can help prevent radon from entering your home. Ask your builder about simple steps that can be taken to build your new home radon-resistant. Many builders already incorporate some of these steps to control moisture or increase energy efficiency and the additional cost at the time of construction is minimal.

Learn more about radon-resistant construction techniques from the EPA

Well water that contains radon may increase the level of radon in a home. Activities like taking showers, doing laundry, or running the dishwasher can release radon into the air.

Learn more about radon in water
Order a radon in water test kit for $25