General Radon Information

New Hampshire specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in New Hampshire, as well as detailed radon level information for every county in New Hampshire.

What is radon? It is a invisible, odorless, tasteless radioactive gas that is produced by minerals like uranium and radium in the soil.

Radon gas decays into radioactive particles that can get trapped in your lungs when you breathe. As they break down further, these particles release small bursts of energy that can damage lung tissue and lead to lung cancer over time. Not everyone exposed to elevated levels of radon will develop lung cancer and the time between exposure and the onset of the disease may be many years.

Radon was first recognized as an indoor environmental health concern in the mid-1980s, and media coverage of the issue both enlightened and alarmed the public. Radon is a Class A carcinogen and the second leading cause of lung cancer. The increased risk of developing lung cancer from radon is directly related to the concentration of radon and the length of time that a person is exposed to it. The U.S. Environmental Protection Agency (EPA) estimates that there are between 5,000 and 30,000 radon-related lung cancer deaths each year. Radon is the number one cause of lung cancer in nonsmokers, according to EPA.

Radon is harmlessly dispersed in outdoor air, but when trapped in buildings can increase the risk of lung cancer, especially at elevated levels. It typically enters a home the same way air and other soil gases enter the home, through cracks in the foundation, floor or walls, hollow-block walls, and openings around pipes, sump pumps, and floor drains. It can also be present in some construction materials and in water from underground sources including private wells. Any home, regardless of age, energy-efficiency, or foundation type, could have a radon problem. The only way to know whether or not a particular home has a problem is to test THAT home.

Slight differences between indoor and outdoor pressure can affect the rate at which radon enters the home. Reduced indoor pressure draws the gas through any cracks and openings. This lower indoor pressure may be caused by open windows on the downwind side of the house, operation of kitchen or exhaust fans, and the use of air by furnaces and other large appliances. The fact that air in a house is often warmer than the surrounding air and tends to rise can also cause reduced indoor pressure. Another means of entrance for the gas is water supplies, particularly underground wells. However, the levels in water supplies in New Jersey are usually not high enough to present a significant risk by themselves. Also, public water supplies usually undergo a great amount of agitation and aeration during treatment, which releases the radon gas before it reaches any residence.

High indoor radon concentrations are more frequently found in the northern, eastern, and southeastern parts of New Hampshire. However, values in excess of the US Environmental Protection Agency’s 4.0 picocurie per liter pCi/L) action guideline have been found in nearly every community in New Hampshire. Values exceeding 100 pCi/L have been recorded in at least eight of New Hampshire’s ten counties. The highest indoor radon reading in New Hampshire that we are aware of is greater than 1200 pCi/L; higher values probably exist.

The Radon Program is responsible for gathering and disseminating information on radon occurrence within New Hampshire, the health effects associated with exposure to radon, and the various means of reducing radon concentrations in both indoor air and water supplies. A statewide radon database consisting of results of indoor radon tests conducted by household residents contains several thousand readings. Geographic distribution of radon test results is used to identify the relative frequency of occurrence of elevated radon levels throughout New Hampshire. Environmental Health Program staff are available to give radon-related presentations and frequently do so for schools, real estate offices and organizations.

What do NH Citizens know about Radon? A 2000 NH BRFSS survey found that 81% of NH citizens had heard of radon. Of those who had heard of it, 93% knew that it was unhealthy. Of that 93%, 49% answered that radon caused lung cancer, 27% answered that it caused another type of cancer, and 24% answered that it caused non-cancer illnesses. The bottom line is that only 1/3 of NH adults are aware of the real health risks of radon.

What are NH citizens doing about Radon? In 1994, only 17% of NH citizens had test their homes for Radon. In 2000, that number rose to 28%.


David Chase