Agency for Toxic Substances and Disease Registry Radon Toxicity Radon Detection
Radon levels cannot be accurately predicted solely on the basis of factors such as location, geology, building materials, and ventilation. Measurement is the key to identifying the problem. Radon detection kits are available in most hardware stores.
Short-term testing (lasting a few days to several months) is the quickest way to determine if a potential problem exists. Charcoal canisters, liquid scintillation detectors, electret ion detectors, alpha-track detectors, and continuous monitors are the most common short-term testing devices. Short-term testing should be conducted in the lowest inhabited area of the home, with the doors and windows shut.
Long-term testing (lasting up to 1 year) will give a better reading of a home's year-round average radon level than will a short-term test. Alpha-track detectors and electret ion detectors are the most common long-term testing devices. Exposed devices are sent via mail to a certified laboratory for analysis. These devices measure radon gas levels, rather than radon progeny; thus, the units reported are in picocuries of radon per liter of air.
The charcoal canister is a small can containing charcoal and a filter to keep out radon progeny. It is inexpensive ($10 to $25) and is generally used for short-term testing (3 to 7 days). The alpha-track device contains a small piece of plastic in a filtered container. As the radon gas that has entered the container decays, the alpha particles form etch tracks. These tracks can be counted using a special technique. The cost of the alpha-track device is roughly twice that of the charcoal canister, and it can be used to measure cumulative exposure over a longer period (i.e., several weeks to a year).
Congress has mandated that each state set up an office to deal with requests for radon assistance. Many states provide radon detection kits such as the charcoal canister free of charge as a public service. A list of state radon contacts can be found in the Sources of Information section.
