Can the seller tamper with a homebuyer's radon test to change the results?
Monday, June 25, 2018
There are two basic types of radon testing equipment: passive and electronic. While no test device is absolutely tamperproof, the passive test systems make it much easier to manipulate the test results downward.
To understand why, let’s first review the Environmental Protection Agency’s (EPA) protocol for the a radon test:
- All windows must be kept closed. Exterior doors should be kept closed, except for momentary entrance and exit.
- HVAC system should operate normally, with the thermostat set between 67º and 77º F.
- Whole-house fans, fireplaces and wood stoves should not be operated.
- The test device should not be moved or otherwise tampered with.
The premise of the test standard is to replicate the way most people live in their homes: with the windows closed and the HVAC system on. It is a “closed house test.” The occupant of the house can come and go as often as they want, as long as they do not leave a door open.
While all houses have a small amount of air exchange between the interior and outside, even with the doors and windows closed, opening them will usually reduce the radon level somewhat. Any kind of air exhaust systems also tend to the reduce the radon concentration, although they may possibly increase it and, of course, moving the test device outside will lower the radon reading significantly.
Examples of passive devices would a charcoal canister or Electret Ion Chamber (EIC). They are both small, simple, and do not require any electric power to operate or have any type of environmental monitoring sensors. The only test result obtainable is the average radon level for the duration of the test. When these systems are used, the single tamper-resistant feature that can be added is securing the device in place with a special tape that shreds when moved to indicate tampering.
Electronic monitors require power, but have a battery in case the power fails during the test. The one that we use, the Radalink AirCat, is a typical electronic monitor and has the following tamper-resistant sensors:
- A movement sensor.
- An air pressure sensor that keeps a continuous log of the opening of any doors or windows and the length of time they remain open.
- A temperature and humidity sensor that also keeps a continuous log to indicate any temperature or humidity changes.
- An hourly radon concentration reading.
A technician at Radalink, in Atlanta, Georgia, reviews all the sensor data, looking for any indications of changes in the test conditions that would indicate tampering, before releasing the final report to the customer. The result is a test reading that is much less likely to have been manipulated. We occasionally have a test voided by Radalink because of evidence of tampering, and the home has to be retested. It does not happen often, but it does happen.
While the passive radon test devices are approximately as accurate as an electronic ones, we suggest using a company with an electronic system to be assured of the most accurate result possible when radon testing for a real estate transaction. Passive devices are just fine for testing your own home or a follow-up test after a radon mitigation system has been installed.
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