If I go to the doctor or the dentist for an x-ray, I presume the machine they use has to be approved by the FDA, as well as other regulatory agencies, and be calibrated on a periodic basis.
Have the backscatter or millimetre wave machines gotten FDA approval, and gone through testing to ensure that they are OK to use on people?
If not, yet another reason not to go through either.
To answer your question: the answer is NO!
There has been no significant pre-deployment clinical testing of the machines. The airline passengers are the test subjects. There is no significant training of the machine operators, there are no known standards for machine maintenance and adjustment, there is no known measurement provided or allowed for radiation flux generated by the machines, and the X ray wavelengths used are a matter of speculation.
A stated air kerma is provided, but, given that these machines have known substantial differences from “standard” X-ray equipment, the air kerma, even if accurate, is pretty meaningless. Those substantial differences include the facts that the Rapiscan devices scan their subjects rather than use simple irradiation, and they apparently use longer wavelength X-rays than do standard X-ray equipment.
In a few years, probably after this administration is over, I predict that there may be an explosion of skin cancer, particularly among those who are already susceptible to skin cancer (BTW, one of the largest risk factors for deadly skin cancer is pale skin). If that occurs, then a few years after that, dermatologists, medical journalists and the general public might start to notice the rise in skin cancer. All the usual culprits will probably be blamed: global warming, the ozone hole, BP and the oil spill, acid rain. Public Service Announcements will probably be made, urging people to ... well, to do some meaningless thing that has nothing to do with what caused the skin cancer. Speeches will be given about how this rise in skin cancer shows just how important it is to support government healthcare. And, if enough people do actually get skin cancer, a lot of lives will be cut short. In a way, the TSA is thus the American Chernobyl.
I’ve worked in the past, and may again, on devices to allow “bladelesss biopsy” (subepithelial, non-invasive, high-resolution imaging) of skin lesions. I’m putting together a research group now to develop other cancer detection techniques. Bladeless biopsy, or other cancer detection techniques, might become very popular if skin cancers become a lot more common. Maybe the Rapiscan company will thus make me rich. Still, I am bound to advise anyone who is interested, that the Rapiscan machines have important operating parameters that have not been released by the TSA. As stated above: if those operating parameters suggested that the machines are safe, they probably would have been released.
In my opinion, you’d have to be wildly optimistic to believe that you will be safe passing through those scanners, even once. I hope and pray that my opinion is wrong. I suppose we’ll find out.