Sounds like BOHICA (bend over here it comes again).
I think it is a fair concern regarding the effects of radiation on the human body. The radiation exposure can add up if one is a frequent traveler.
Reminds me of trips to the dentist. I would be covered by a lead apron over my body and neck while the assistant would activate the x-ray machine from outside the room.
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Not completely related to these scanners:
Years ago when traveling with film camera, I used a lead lined bag for my film that was carried in the carry on luggage. I was stopped. Instead of looking at the lead lined bag, the security personnel was more interested in the box of 40 Hersey chocolate bars I was carrying.
I thought it was funny, yet sad at the same time. This did not make me feel that secure.
I think that much of these security procedures will only catch the "non professional" or unprepared "problem makers".