I've had a change of heart. After announcing previously that I would forgo additional back-and-forth from scientists about the hazards, or safety, of new TSA scanning machines, I've received enough interesting mail that I think I should offer at least one more installment.
The two original disputants -- a physics professor, and a biophysicist/enzymologist -- were both skeptical of the TSA's overall screening strategy. But they differed on which kind of machines might pose hazards, and why. Here are some additional views. If you read to the end, you'll see some distinct areas of disagreement -- and also some interesting similarities.
First, from a professor at a major research university:
>>I'm not sure whether the continuing lunatic exploits of the TSA have been driven more by terrorized bureaucrats or greedy lobbyists, but in either case I despair for the future.
I'm a tenured Professor of Theoretical Physics at [a major university], and I've been on the faculty for [several decades]. I'm not sure I agree with everything your physics correspondents have written over the past few days, but I certainly agree fully with one thing: In spite of the nominal radiation limits cited for the xray and submillimeter wave AIT machines, there is absolutely no assurance of the amount of radiation actually delivered to an individual subject. Perhaps if each person were issued a dosimeter print-out or a radiation technician were on the job full-time at each machine, there would be some reason to trust the technology. At present the TSA's attitude seems to be, gee, what a neat technology, let's radiate the entire population and look for problems later. The situation is bizarre, particularly in view of the stringent safety precautions mandated in other parts of American life. Um, thanks, but the radiation machines are not for me or my family.
By the way, I can think of multiple inexpensive ways to evade the strip search technologies, some of which I find were already discussed in the Journal of Transportation Security article. I hope that GAO teams, but not our enemies, are hard at work on exposing the flaws.<<
I wrote back to this professor saying that I planned to quote his note -- and confirming that I should not use his name. He replied:
>>I guess it would probably be best if you did not mention my name or university. I'm
not at all concerned as a faculty member, but I am also [an administrator], and I'm not sure I should comment openly on the TSA while I have the administrative job.
I've never found myself in the position of feeling so strongly on an issue and yet
hesitating to speak out because of my job. You can be sure I admire pilot Chris Liu :)
More after the jump, largely on the question of how public agencies (like the TSA) and members of the lay public (like us, in the scanning queues) can reach sensible decisions about matters on which experts disagree.