Tracking Radon

In New Hampshire, potential exposure to radon is greater than the national average due to our granite bedrock. In the U.S., the average level of indoor radon is 1.25 picocuries per liter (pCi/L) but here in NH, it is estimated to be 1.8 pCi/L.

Radon is a naturally occurring radioactive gas that emanates from soil and bedrock, including granite, and can seep into homes primarily through cracks and seams in foundation floors and walls. It may also enter through well water. Radon is a known carcinogen, a substance capable of causing cancer in living tissue. When radon accumulates in indoor air, it poses an increased risk of developing lung cancer.


Measuring Radon

The concentration of radon in the air is measured in units of picocuries per litre (pCi/L).The US Environmental Protection Agency (EPA) has established 4.0 pCi/L as the level at which action should be taken to reduce radon to under 2.0 pCi/L.


New Hampshire Communities at Greatest Risk

In general, communities in southeastern and eastern New Hampshire have the highest percentage of homes with elevated radon levels. Rockingham, Carroll and Coos counties have several communities in which more than half of the homes tested had elevated radon.


Health Risks from Radon Exposure

Almost all risk from radon comes from breathing air with radon. Exposure to radon gas is the second leading cause of lung cancer in the United States, with more than 21,000 deaths attributed annually to radon-related lung cancer. Radon is associated with approximately 100 lung cancer and related deaths in New Hampshire residents each year.

It is important to realize, there is no safe level of radon. Any exposure poses some risk of cancer. Smokers have an increased chance of developing lung cancer in a home where radon gas is found.


Testing for Radon

There are "do-it-yourself" radon test kits available through the mail, in hardware stores and other retail outlets. If you prefer, you can hire a nationally-certified radon measurement professional. 

For information on certified radon contractors, visit: