> You're exposed to so much radiation just sitting in an aircraft at 35,000 feet that anything beamed at you during security screening would have to be of very little consequence.

I've heard this before, but this really isn't how radiation works.

The higher dosages you're exposed to and the longer, the more likely the negative affects.

But it's strangely additive, like getting wet. Which is a poor analogy but the most fitting I can think of.

You might get "more wet" by standing in the rain than getting splashed with puddle, sure, but you're still increasing your "wet-ness" by not drying out before getting splashed.

Only this wet gives you cancer if you stay wet too long, or get too wet.