Radon is a gas that occurs naturally from the decay of radioactive metals in the earth. While it may seem insignificant, radon is the second leading cause of lung cancer in the United States, according to the EPA. Because radon is colorless, odorless, and tasteless, it can be present in dangerous concentrations in your home without you even realizing it!
Testing For Radon
There are multiple methods for testing radon levels. They fall under two main categories short-term and long-term. As the name suggests, some tests are focused on giving a quick snapshot of radon levels in a home. Whereas others are focused on giving an overview of radon levels during an extended period.
Short-term Tests are preferred in real estate transactions due to the time constraints of closing on a home. Standard radon tests for real estate transactions typically take 48 hours and offer good insight into the radon levels in a home. Test protocols require closed-house conditions. This means all windows/ doors are kept closed (except for entry/ exit) for the entire duration of the test and starting at least 12 hours before the test. This method helps replicate the conditions where radon levels might be highest and provides more meaningful results.
Long-term Tests are used in order to test radon over an extended period. This test takes at least 90 days and gives a better picture of the annual average radon levels of a home.
Testing Methods
The two most common types of radon testing methods are activated carbon absorption and continuous radon monitoring.
Activated Carbon Absorption utilizes a canister filled with activated charcoal. The canister is left in the home for anywhere for at least 48 hours (or over 90 days for a long-term test). The charcoal absorbs radon gas. The canister is then sent to a testing lab where the radon levels are measured. This test ONLY gives you an average level of radon over the test period.
Continuous Radon Monitors are scientific instruments used by professionals to take hourly radon measurements over the test period. Thse are the preferred tests for short-term radon testing as they offer the most accuracy and precision. Additionally, the results are available immediately upon conclusion of the test, whereas Activated Carbon tests require waiting for the lab to analyze the results. The devices we use at Holston Home Inspections are certified by the National Radon Safety Board and provide additional information such as humidity levels and atmospheric pressure.
Mitigation Techniques
Once you have the results from the radon test, we will provide a recommendation for necessary mitigation. Radon levels are measured in the US in pCi/L (picoCuries per liter). The EPA recommends mitigation if radon levels are 4 pCi/L (picocuries per liter) or greater. However, no level of radon is considered safe, so it is recommended a mitigation system be considered if levels are between 2-4 pCi/L.
The design of a mitigation system to be installed on your home depends on the type of construction. However, most systems use negative pressure to remove the radioactive gas from beneath the home and vent it outside. Essentially, the systems function like a big vaccum through the use of a powerful fan, removing dangerous gas from your home. Here is a link to a diagram that does a good job of demonstrating common sytem design.
In Summary
Whether you’re a current homeowner or a prospective buyer, a radon inspection is essential to ensure the safety and well-being of you and your family. In fact, Sullivan, Washington, Carter, Johnson, and Greene counties ALL have average radon levels above the safe threshold, according to the Tennessee Department of Environment and Conservation. This translates to approximately 1 in 5 homes needing a mitigation system. If you live in Johnson City, Kingsport, Bristol, or surrounding areas it is extremely important for your health and safety to have your home tested for radon. Use the button below to schedule a radon test.