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Radon & the Empty House



Richard Acree

President, HABITEC Home and Building Inspections, LLC

January is the National Radon Action Month. This is a story about radon that everyone in Middle Tennessee should read.

Recently I inspected a large home with a foundation that consisted of a crawl space and a partial basement. The home was sophisticated in design and construction including a moisture extraction system for the crawl space. This system was active at the time of the inspection. Also, the crawl space moisture barrier was well done and in tact.

Like many houses for sale these days, this house had been on the market for approximately 8 months and had been vacant for most of that time. Wisely, in addition to the Home Inspection, my Client requested a radon test on the house. Unfortunately, the house tested positive for excessive radon gas with a Continuous Radon Monitor reading of approximately 6.0 pico curies per liter (pCi/L). This despite the active moisture extraction system!.

The listing agent approached me about the reading after discussing these results with the builder and another measurement technician. Both of those two individuals convinced her that the radon measurement reading was high because no one had lived in the house for many months. The listing agent suggested that when the Client/buyer moved into the house the radon gas level would go down because of the normal coming-and-going of a family. She went on to suggest that I inform the Client/buyer of this “fact” by frequently repeating that “this is a valid point”.

While I agreed with the “premise” that the radon gas level may come down under normal occupancy, my questions to the listing agent was “How low will it go with normal occupancy?” And, “Is she or her contacts willing to guarantee to the Client that the radon gas level will not only be lower but within EPA guidelines?” Silence.

The point of this article is that we will all see many homes now that are in areas prone to radon gas intrusion and that have been sitting vacant for some time. Regardless, if the radon gas concentration is at or above 4.0 pCi/L, the EPA says the home/building should be mitigated. There is no allowance within EPA guidelines for how long the house has been sitting empty. In fact, the purpose of the Closed House/Building process is to create the worse case scenario for radon gas concentration by closing the building as much as possible for 12 hours prior to the test and then during the test. These days, 12 hours of closed house conditions before starting the test is all too easy to come by.


Background Information about Radon

Radon is an odorless and invisible radioactive gas that is produced from the natural breakdown of the uranium found in most rocks and soils. As the breakdown occurs, radon emits atomic particles and gas into the air we breathe.

Once inhaled, these particles can be deposited in our lungs. The energy associated with these particles can alter cell DNA, thus increasing the risk of lung cancer. In fact, the Surgeon General of the US has warned that radon is the second leading cause of lung cancer in the US. The National Academy of Science estimates that radon causes between 15,000 and 22,000 lung cancer deaths each year in the US. Any home can have radon. The only way to know if your house has a radon problem is to test (sample). For this reason, the EPA and Surgeon General recommend testing all homes for radon every two years! (HABITEC recommends testing homes with basements every year!)

On average, 1 out of every 15 homes in the US is estimated to have an elevated radon level. The risk of radon exposure varies by location. The EPA has designated 3 zones of risk in the US, based on geological surveys. Zone 1 is a High Risk area, Zone 2 is a moderate risk area, and Zone 3 is a low risk. Most of Middle Tennessee is in a Zone 1 area or at High Risk for radon gas exposure.

HABITEC Home and Building Inspections, LLC, is a company specializing in building inspections for residential and commercial buildings. Additionally, we offer environmental services to evaluate a structure for radon, mold and water quality. Should you wish to schedule a radon measurement, please call Richard Acree or Ron Rittiner at 615-376-2753. Richard A. Acree is certified by the National Environmental Health Association as a Residential Radon Measurement Provider.

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