Continuous Radon Monitoring vs. “the two little vials” – Facts and Myths about Radon Gas Testing – Part I
Posted by Mike Ciavattieri on Mon, Dec 14, 2009 @ 12:32 PM
Over my 10+ years as a Massachusetts Home Inspector, I (like many others in my profession) have seen a huge increase in the percentage of well-informed clients that are requesting radon gas testing as an additional service along with their home inspection. Several months ago I added continuous radon monitoring (CRM) - also loosely known as "the machine test" to my service arsenal, while continuing to offer the more economical liquid scintillation test - aka "the two small plastic vials".
I routinely get quizzical questions from clients ranging from ‘what is radon' , ‘why should I test for radon', ‘what's the difference between the two methods' , and my favorite - ‘why should I pay you when I can do it myself?' So, I thought I was time to devote a couple of blog installments on this rather important and somewhat mysterious subject. Here goes:
One common misconception about the two test methods is that the ‘machine test' is more accurate than the ‘vial test'. The bottom line is there is no difference in accuracy. Doesn't it make simple common sense just based on all of the potential implications? Think about it. The USEPA maintains strict protocols for placement and QA/QC for both types of devices. Upon close examination you'd find that for the most part, the protocols are nearly identical! So don't get sold into paying more based solely for accuracy - it simply isn't there. Analytical Organizations that provide vial test kits for testing must remain in compliance with the USEPA's strict QA/QC protocols in order for their devices to retain their product certifications. The same goes for Home Inspectors and the like providing continuous radon monitoring services.
Another common misconception is that there is some sort of ‘magic formula' for making a pre-determination about a property without actually testing for radon - there isn't. Brand new homes, old homes, stone foundations, concrete foundations, etc. - none are immune. No one in the neighborhood has radon? No matter - soil concentrations of radon can vary as much as 300 times over as little as 30ft of distance. The bottom line is that radon gas testing is the only way to make an accurate determination. I've had many an unsuspecting property and/or property owner be surprised by significantly elevated radon gas levels.
Which leads me to my final point: Accurate determinations require accurate testing. Yes, the average handyman can easily purchase the $30 hardware store kit. The truly difficult part comes with correctly following the placement protocols and the interpretation of the results. The average hardware store kit instructions at best fill up a few paragraphs on a single page - the USEPA's Protocol for ‘vial kits' takes up an entire page and half just for device placement! A lot of this critical information simply isn't on the average hardware store kit instructions! I've stumbled across many an incorrectly setup hardware kit over the past 10 years - and in almost all of those cases, those placement mistakes were almost certain to induce false negatives. Why risk it for another handful of dollars? Have a professional place your radon test kit.
In part II, I'll cover some of the pros and cons for each testing method. See you then...