Thanks to XKCD for making this Radiation Chart available on the web. This will help you visualize and understand the various levels of radiation. Simple things to know, you get 3x the amount of radiation by living 50 miles from a Coal plant than you do from living 50 miles from a Nuke plant.
I’m anti TSA back scatter scanner, but it’s not because of the radiation, which is actually quite small. Coming in at a measure of 0.005 mrem, it’s about 1/2 of what you get by eating a banana. If you live in a brick house you are getting at least 20x that radiation level every day.
I’m anti back scatter scanner because I think it’s a 4th amendment violation, and that it’s an incredibly expensive waste of money. That money could be better spent on kitchen safety, as kitchen appliances kill more people a year than terrorists do.