The current arrangement subjects you to one short burst of radiation to take a static image, and it's enough energy to have some doctors worried. Multiply that up by however many frames you want to capture, and I don't think it would be "some doctors" any more.
Besides, I've got no idea if the machines in place have microwave units that can withstand a high duty cycle like that. I wouldn't be surprised if they can't.
Does anyone have some independently verified numbers for the amount of radiation that a FBS exposes a passenger to and how it compares to the amount of radiation exposure the same passenger would get from 3 hours in a plane? The TSA claims that the latter is significantly (like 100x) greater than the former.
There are numbers out there, but the problem isn't just the amount of energy, it's where it's concentrated. The theory goes that because of its very short wavelength everything that gets absorbed is concentrated in the topmost layers of the skin, so the energy density where it might be damaging is much higher than the absolute amount of energy might suggest.
From memory part of the argument was that the studies hadn't yet been done which might show whether this could be a health issue, so claiming the scanners were safe was at best premature.
(side note: I have the HTTPS version on my clipboard because I hesitated before typing "radiation dosage" into google, and decided to load up Tor to search for it.)
Besides, I've got no idea if the machines in place have microwave units that can withstand a high duty cycle like that. I wouldn't be surprised if they can't.