The Hollow Certification Game
Many RADON testing companies will come into your home with fancy electronic RADON detectors, set them up for 24 -48 hours, then read-out the numbers on the gauge and tell you what it says. Most all of those technicians have absolutely no idea what that detector does and what the numbers mean. They'll tell you they're "Certified" by some fancy "Certification Organization" but the truth is, they spent between 20 and 40 hours in a classroom, passed a written examination and have very little experience; but, they're given a fancy patch, a fancy certificate, and in most cases, a uniform to make them look professional.
Is that what you want to base the safety of your health on?
In addition, the so-called Certification Organizations are merely private corporations who have set themselves up as self styled "Certification Venues". Their self interest is in cycling as many people through their private certification classes as possible to make as much profit as possible. There is absolutely ZERO interest or inducement for these private certification companies to oversee their "Certified Technicians" and ensure they are performing their job correctly, and there is absolutely no process used to suspend the certification of any technician who does a poor job or his/her job incorrectly.