Buying a home is arguably one of the biggest purchases most families will make. Having an experienced Realtor ™ working on your behalf helps ensure that "all the bases are covered" and your best interests are protected.
When radon testing for a home purchase is required, buyers should make sure they use a "certified" radon test professional to conduct the testing. Being "certified" in radon testing means that you have passed a proficiency exam on the proper EPA testing protocols that are required to ensure a good test. Sellers ALSO should insist that any individual engaged by the buyer to perform their test be "certified" as well because not following EPA procedures could allow "abnormal test conditions" to exist which "could" affect the test adversely. If elevated levesl are encountered due to a fault or ignorance of the tester, it could create a financial "penalty" for the seller.
Furthermore, another criticial component to obtaining valid information that can be used to make a wise financial decision is the "exclusive use" of continuous radon monitors (CRM's) to perform the test.
Charcoal test kits have frequently been used for this purpose. However, continuous monitors have several distinct advantages over charcoal kits.
1) They take hourly radon samples which illustrate what levels existed in the house for the duration of the test. Charcoal kits produce an "average" for the test period, but they dont document HOW the average was obtained. The use of CRM's can sometimes pinpoint whether or not "test tampering" took place.
2) Most good continuous monitors have a built-in "motion detector" that indicate on the print report that the monitor had been "touched/handled". A charcoal kit could easily be removed from the deployed location and placed outside until shortly before the inspector returned. Even though attempting to conduct the test "in good conscience" the tester would NOT KNOW that the the test had been compromised and would report the readings obtained to the client "thinking" that they had acted appropriately.
3) Charcoal kit test results are "biased" towards the last 12 hours or so of a test because that is when the radon particles are strongest. Night time tends to be produce higher radon levels than tests conducted during the day. If a home inspector starts a test at 9 in the morning, that means using "previous 12 hours" would be primarly be "night hours" which tend to be higher. Continuous monitors take individual "hourly samples" which stand on their own merit.
4) Charcoal test kits can be adversely affected by excessive moisture in a house. (Especially if the tester didnt pay attention to the weather report that was predicted for a prospective test period). Many continuous monitors record "humidity" readings that help assess what conditions existed in the house during the test but they are not adversely affected by moisture.
5) Charcoal kits are passive devices which must be sealed up and sent to a radon lab for "processing" and "analysis". This routinely takes several days to get results back. Continuous monitors are able to generate the test average "immediately" upon test termination. With critical deadlines that most home closings have, its simply "too risky" to depend upon Uncle Sam to get your test kits to a lab when you need them the most! Most buyers won't walk into a closing without a definitive "answer" regarding the radon levels in the home they are purchasing. This "concern" is not an "issue" for a continous monitor assuming that enough time was provided to the certified professional to conduct the test.