Radon Gas Testing
Radon Gas Testing

Radon gas poses a serious health risk for many people. It is a colorless, odorless, tasteless gas and your home, workplace, or school may contain high quantities without anyone's knowledge. The only way to know if there is a problem is to conduct a test.

What is Radon Gas and How Does it Enter a Building?

Radon is a gas produced by the natural decay of uranium. All rocks and soils contain some uranium, albeit usually in small quantities, therefore radon is a commonplace substance. As with all gases, radon seeps through cracks and other apertures and expands to fill spaces.

Thus, radon may enter through cracks in building foundations, cracks and gaps in walls, spaces around pipes, construction joints, and gaps in suspended walls. Radon may also enter through the water supply although most experts consider the threat from water to be less substantial than through the ground.

The United States Environmental Protection Agency (EPA) estimates that as many as 6-7% of all homes in the United States are affected by dangerous levels of radon, potentially affecting tens of millions of people. Your home may be affected without your knowledge.

Although some geographic areas experience higher levels of radon than others, one cannot use mapped data to safely predict levels of radon. Cases have shown neighboring houses with widely disparate levels. Testing for radon represents the sole method of gauging the risk for a particular building.

What are the Health Risks?

Breathing radon deposits small radioactive particles in the lungs that, while decaying, generate energy bursts. These bursts of energy cause severe damage to lung tissue and may cause lung cancer. Radon is considered the second highest cause of lung cancer after smoking tobacco, causing between 7,000 and 30,000 deaths per year. Various health and environmental agencies and associations rate radon as a severe health risk.

However, an additional danger is that there are no short-term health risks and thus symptoms do not appear until the problem becomes serious. People at the highest risk include those who live on the ground floors of buildings and smokers.

Radon Testing

Tests for radon in the air measure "picoCuries per liter of air," or "pCi/L." As a more easily understood measurement, some prefer to express results as "working levels" (WL), using a conversion of 4 pCi/L to 0.016 WL. Tests use various methods including electret ion chambers, charcoal canisters, alpha track, charcoal liquid scintillation and continuous monitors.

Radon Levels to Look For

Both short-term and long-term tests may be conducted. Short-term tests range from as little as two to ninety days, long-term tests from ninety days to one year. Although short-term tests reveal pCi/L levels more quickly, long-term tests give more accurate indications of average year-round levels.

A short-term test that reveals a level of pCi/L of "4" or more indicates a possible problem and in those cases, many experts recommend a second short-term test as quickly as possible to confirm initial readings. Many retail outlets sell "do-it-yourself" test kits for $10 to $45. These test kits area also available through the mail. However, others prefer tests to be conducted by professionals.

Residents in the United States should check to ensure that a professional testing company is certified by the particular state and/or has a listing in the EPA's Radon Measurement Program. Official state radon information officers and the Radon Helpline (800) 557-2366 offer citizens the EPA's list and the Radon Proficiency Program maintains an on-line listing of certified contractors.

Best Practices for Using a Radon Test Kit

The test kit should be placed at the lowest frequently-used room possible in the building, the basement if there is one and is used often. Kitchens and bathrooms are not recommended. You should take care to place the kit well, at least twenty inches above the floor, in a spot where it will not be disturbed, and unaffected by drafts, high heat, high humidity, and exterior walls.

Doors and windows should be kept closed for as much as possible during the test and for at least twelve hours prior to the test, however occupants need not vacate the building. Although internal fans, air-conditioning systems, and heaters may be used, air-circulation systems that introduce air from outside the building should be avoided as they may distort readings. Testing should also be avoided during stormy or windy conditions.

After the test is completed, reseal the kit in its package and send it to a the specified laboratory as soon as possible. Laboratory results usually require a few weeks.


In conclusion, radon represents a severe health risk, causing lung cancer. It is found worldwide and most citizens, especially those who reside in the ground floors of buildings, should test for radon levels. Do-it-yourself, short-term tests are available and cost relatively little.