[shallowwater]

Basically, yes. It's very easy to end up herded through unless you're paying attention. Now I watch carefully and see which lines are going through the big scanner and which are going through the smaller metal detector. Most of the time, I can just get in the metal detector line, no muss no fuss.

However, when it is unavoidable (happens at smaller airports when there are fewer lines in my experience), I just stop in front of it and say in my most polite sweet little thing voice "no thank you" or "I don't want to go through the radiation scanner" when I'm told go through it. I've had people try and tell me it's safe and (gently?) badger me into doing it (at which point sometimes I try and offer a reason, but mostly I just say "I don't care"), but every time I've been on my toes enough to refuse, I've gotten the patdown instead. The TSA folks have sometimes gotten kinda freaked out/uptight or antsy, but it generally blows over pretty quickly and 80% of the time doesn't take much longer than the regular screening. The rest of the time, it takes them 15 minutes to find another lady agent to do the patdown, so I always start through security a little sooner if I can't see separate lines for a metal detector-only screening.

I also refuse to go to the 'private' screening area. If they're going to grope me, I'd rather it be in public in full view of everyone else.

[mortenjorck]

If anyone ever tells you the scanners are "safe," you need only mention (innocently and with utmost politeness, of course) that they have been banned in the European Union over health concerns.(1)

(1)http://www.forbes.com/sites/daviddisalvo/2011/11/15/europe-b...

[capnrefsmmat]

That's for the X-ray backscatter scanners; millimeter-wave scanners are in common use in the US as well, and are safe as far as we know.

[benmccann]

There are X-ray backscatter scanners in use in the U.S. For example, they are used in San Jose airport, which is probably the airport most used by HN readers.

[SoftwareMaven]

"as far as we know"

Is there good, unbiased evidence of that? I don't trust the manufacturers nor the government, but I also don't believe because electromagnet waves are involved, it is inherently toxic.

[joe42]

X-rays have enough energy to break molecular bonds in your body (ionizing radiation), millimeter waves do not.

[libraryatnight]

Is there a way, at a glance, to recognize x-ray vs millimeter machines?

[hammock]

In the US, the backscatter x-ray machines are two giant ugly blue boxes that you stand between. The mm wave machines are more futuristic-looking, white cylinders that you stand inside of. (photos here http://www.flyertalk.com/forum/practical-travel-safety-issue...)

The technology deployment is airport-specific, so you will only find one or the other at any given airport, e.g. O'Hare uses Backscatter, Midway uses mm wave.

La Guardia is the one airport serving a major US city that does not have any of the new scanners, which can be nice if you typically opt-out.

[jchrisa]

Even if there is, I'm guessing it would be hard to tell at a glance whether the machine was calibrated by someone with a physics degree or someone who'd be delivering pizzas if it weren't for the growth of the security industry.

[shallowwater]

I can in no way substantiate this, but the xray ones are usually two large (maybe always blue?) mostly rectangular blocks that you stand in between. The millimeter machines are usually rounder and have clear bits. The illustrations here might help: http://www.jaunted.com/story/2010/1/5/163631/3181/travel/Ful...

edit: never mind, the flyer talk pics are much better.

[frig8]

Currently deployed scanners operate in the 24-30 GHz range. Generally, microwave radiation is considered safe as long as it's not intense enough to cause burns.

http://en.wikipedia.org/wiki/Microwave#Health_effects

[shallowwater]

ha! I will bust out my best sweet thing voice and biggest innocent eyes next time some one tries to tell me that. Even if it does only apply to the xray machines.