Radon is a colorless, odorless gas produced by the decay of elements in the soil. It usually enters a home by seeping through cracks in the basement, foundation, sump pump or pipes and can be detected through proper testing. Testing radon levels is one of the most difficult environmental problems to accurately measure. Reasons for this include interference from such factors as air movement, cigarette smoke, water table levels, barometric pressure and even the season of the year, all of which can affect the readings.

Although difficult to measure, radon problems are relatively easy and inexpensive to mitigate when compared to correcting other environmental problems. Types of testing devices can either be passive or active. Passive devices include charcoal canisters, alpha-track detectors and charcoal liquid scintillation. These testing devices are available at hardware and houseware stores and generally require at least 48 hours to complete.

Active devices include continuous radon monitors and continuous working level monitors, and require operation by trained testers. Many of these devices provide a continuous report of radon levels present, revealing any unusual or abnormal swings in the levels during the test period (usually 48 hours or more). These devices are specifically designed to deter and detect test interference. Although these tests may cost more, they ensure a more reliable result.

Whichever testing method is employed, make sure the test is approved by the Environmental Protection Agency (EPA). Once the level of radon is known, it may be necessary to mitigate the problem. It may be as simple as sealing any cracks in the floors or walls of the basement, foundation and/or crawl space since that is how the gas enters the home in the first place. Or, the air from the basement or crawl space may need to be vented. A state-licensed radon mitigator can more fully discuss these and other options.  

In the United States, the radon threshold for concern is 4.0 picocuries per liter or higher, whereas a picocurie is one-trillionth of a curie -- the measure of radioactivity found in a gram of radium. A measurement at these levels indicate some type of action should be taken to avoid possible health threats.

In general, REALTORS are not qualified to inspect for, detect the presence of, advise customers or clients about, or remediate radon gas. Always consult with an environmental professional when dealing with radon gas issues.

The FAR-BAR "AS-IS" Residential Contract for Sale and Purchase addresses radon in Section 10:

10. DISCLOSURES:
(a) RADON GAS: Radon is a naturally occurring radioactive gas that, when it is accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time. Levels of radon that exceed federal and state guidelines have been found in buildings in Florida. Additional information regarding radon and radon testing may be obtained from your county health department.

The Florida REALTORS Contract for Sale and Purchase (CRSP) addresses radon in Section 7: Real Property Disclosures

(b)   Radon Gas: Radon is a naturally occurring radioactive gas that, when it has accumulated in a building in sufficient quantities, may present health risks to persons who are exposed to it over time. Radon levels that exceed federal and state guidelines have been found in buildings in Florida. Additional information regarding radon and radon testing may be obtained from your county public health unit. Buyer  may, within  the Inspection Period, have an appropriately licensed person test the Property for radon. If the radon level exceeds acceptable EPA standards, Seller may choose to reduce the radon level to an acceptable EPA level, failing which either party may cancel this Contract.