[jcl]

From an NPR blog entry:

By the way, you might be wondering: Can the average traveler standing in a security line tell the difference? Yes, a TSA spokesman says. The X-ray type is blue and has two walls. The millimeter-wave machine is grayish-white and is more cylindrical.

http://www.npr.org/blogs/health/2010/11/12/131275949/protest...

[ars]

Thanks. Just how shielded are those X-ray scanners?

They look like just walking near them will expose you.

[jessriedel]

You could stand next to them all day and it would still be less than 1% of your daily radiation dose from cosmic rays. More importantly, for argument's sake, it would be much less than the amount of additional radiation you pick up on a standard flight.

[ars]

I know, but I still don't want unnecessary radiation.

[mkramlich]

stay out of sunlight. don't eat bananas. don't use cellphones. don't stare into a computer screen. don't have a WiFi network in your house/office. and probably don't have a microwave oven either, just to be safe. Because none of those things are necessary. ;)