Didn’t the original full body scanners used at airports use backscatter X-rays, which are ionizing radiation ?

I believe these were mostly replaced by millimeter-wave scanners, and are not used anymore (even banned in some countries) but a lot of the initial pushback and debate surrounding the scanners when they were first introduced was about potential health risks of repeated X-ray exposure from those scanners, and so the idea of ionizing radiation exposure persists to this day in many people’s minds.