The airport scanner situation is somewhat unclear. It appears I was misled by the photographers fear-mongering... somewhat, at least. When I looked in detail at the GE linked website about the CTX scanners, I found it to be completely unhelpful. I found no solid support for that photography website that claimed up to 300mR could be inflicted by a CTX scanner. However, some articles and serious investigations have done written about this, and some manufacturers of small scanners are happy to give their low-ball figures. I'll try to distill what I found out here:
The total dose applied in a typical luggage scan is, as you say, definitely under 1mr, though that dose is applied at a high radiation rate. However, apparently if something suspicious is found inside
checked luggage, some XRay machines such as the CTX models mentioned above, can switch to a "second scan" which is equivalent to tomography. That will raise the dose the luggage gets by large amounts, and THAT is probably what the photographer was warning people about, and indeed I found quite a few pictures on the web demonstrating the wide (about 10-15% of film width) "stripe" of damage that shows up VERY PROMINENTLY on fast film (ASA800) with this machine. Sorry, I didn't save a link to the any of the images, but they aren't difficult to find on the photography sites on the web that have studied this. Also, it is clear that not every "stripe" of the luggage gets the same dose - some parts really can get hammered, though.
From GE's site:"Like all GE CTX EDS machines, the CTX 5500 DS system uses technology derived from medical Computed Tomography (CT) to help locate and identify explosive devices concealed in checked baggage. As the conveyor moves each bag through the machine, the system produces a scan projection X-ray image. Using sophisticated computer algorithms, the CTX 5500 DS system analyzes these slice images and compares their properties with those of known threats."
Carry-on luggage is different: if something looks suspicious with the low-radiation scan, they'll simply have you pop it open, and there is never a high dose risk. Lesson: take film in carry-on, for sure. There are claims that the dose is safe for up to ASA1600 (very fast) film with some machines. However, if you have to go through many rounds of scans, it the effect is clearly cumulative, so I wouldn't depend on this too much if you're a professional film photographer - you could find yourself with foggy fast film for sure.
The "leakage rates" for all the scanners are all sub-mrem/hr, despite the high radiation dose rate used for the scans within the scanners (which I was not able to determine at all). Again, no surprise.
And for anecdotal amusement, a blog had this from a photographer who did his own experiment, and this agrees nicely with the more professional studies:
Jonathan Kroner , apr 05, 2002; 10:33 a.m.
On a recent trip from Miami to Bangkok (approx. 26 hours in the air) I had 9 rolls of 800 speed fuji hand inspected and one roll (which was already in the camera) was subjected to one "film safe" machine. All the film was developed and printed before returning. The "film safe" role was visibly duller than the rest. Standing alone, I might not have noticed the quality degradation of the "film safe" roll. However, in contrast to the others, it was obvious that "film safe" machines can degrade film quality. Also, that long flights do not visibly degrade the film. Prospectively, when it matters, I will purchase and develop film at my destination.
Robert Segal , apr 05, 2002; 10:45 a.m.
For "film safe" read "film not-so-destructive-as-a-CTX"
Bottom line, as I said in my concluding remarks in my Post#48, the baby is quite safe from any "radiation exposure" damage from this incident, though I might worry about damage from his exposure to his caretakers. That was the entire point of my post.
Thanks for the reasoned discussion. I have to go now. I wish you a Merry Christmas.