Thank you Gary. That's a great resource. Just the sort of thing I was looking for. It really makes clear what a huge difference there is between rad from a CT and from an xray. I'm still not clear on where barium swallow tests fall in there though.

I think I do need to start a record of all the radiation-related things I have had, just to use when I talk to doctors about additional procedures, as that document suggests that patients should do. It also reminds me I should get the radon in our house tested again (we had a test that was within limits before we bought the house, but it had been closed up for months and I understand sometimes radon can actually test low under those circumstances--high radon is a problem around here--including for people living just down the hill from us who have had to do radon remediation).

Nelie