Yes... the actual radiation argument is not very strong... UNLESS you work for the TSA and are running the scanners... THEN, you are getting a dose of radiation from EVERY scan, and THAT over the course of a year would push a person well beyond the 'safe' exposure limit.
As to your question, if you're going based off the original claims of the x-rays generated, it has come out since then that it's 20 or 50 TIMES what was originally stated, depending on which machine. Further, Napolitano LIED by saying John Hopkins university called it safe, when the doctors actual statement was more along the lines of 'statistically SOMEONE is going to get skin cancer from those machines'.
But ya, the radiation is a weaker argument... one that should be relegated to " ... and also it gives you a dose of radiation"
I would ask though, since you have experience working with radiation, what do you think of the guidelines these TSA agents are following in their use of the scanners?? (Ie : not going to the other side of a lead wall, no radiation badges, no radiation training, etc.?)
Well the only dosage I have seen is one that says that a scan gives about 2 microrem of radiation. So even if it is 20-50x that much that would only be about 40 to 100 microrem. The yearly limit is 5000 millirem. So we're talking a very miniscule dosage.
And the farther back a person is from the machine, the less they will be exposed to. When dealing with radiation we always consider time, distance, and shielding. Here is the distance equation.
Distance Calculation
(BTW, the "mR" stands for milliRoentgen which is generally equivalent to a rem, depending on the type of radiation, the calculations do not change however, no matter if you are using mrem or mR)
So, if the operator is 5 ft away from the source and the person being scanned is a foot away from the source, and the source is giving off 2 microrems per scan at the assumed 1 ft away, then the operator is only receiving about .04microrems per scan. This doesn't take in the shielding though provided by the machine itself, since the person being scanned is inside the machine with metal around it, and many things provide different amounts of shielding, depending on the type of radiation. Now, I have no idea what the actual numbers are for how far away the operator is from the source compared to how far away the person be scanned is, but one of the easiest ways to cut down on the radiation received by the operator (if it is a concern) is to change where the operator sits and/or add more shielding to the outside of the machine. Even TSA though, would have to abide by the radiation limits already in place for people who work with radiation.
I wonder who these doctors are that believe it will cause skin cancer. The chances of getting any cancer from even working around ionizing radiation from nuclear power (which are higher levels and doses than these scans are) is only increased by .04% when considering the average dose received by a worker over their lifetime. It doesn't make much sense that such a smaller dosage would be likely to increase the chance of getting skin cancer by any significant amount.
I can understand pilots and other aircrew being concerned, since they already receive a high amount of radiation from the many flights that they do take. So getting extra from these machines would be taking a risk of going over limits (and a huge waste of money), although even for them it isn't likely unless they are pregnant (expectant mothers have lower limits).