[pmoriarty]

The radiation may not be that much, relatively speaking. But it's all focused on your skin.

Plus, this kind of radiation exposure hasn't been tested on humans for long. I'd feel better about being scanned had these scanners been in use for 20 years without many adverse effects reported. As it stands, the jury's still out. And I'd personally rather wait a little longer in line and get a pat down than take a chance with my health.

[ggoss]

It also depends on whether the machine in use (different airports use different machines) are millimeter wave or backscatter x-ray. Millimeter wave machines (the majority of installations), if I am not mistaken, do not emit ionizing radiation, whereas the backscatter machines do. You can tell which type of machines are in use at your airport by the informational posters displayed in the queue, the brand and physical appearance of the machines themselves, or by checking online. My policy has always been to ask for a pat-down when they use backscatter (to avoid the unnecessary radiation), and go through the machine if they use millimeter wave. The dose of radiation may be small (relative to normal amounts of cosmic radiation or black lightning or bananas or ...), but they don't really know if the machines are out-of-spec until, well, they do. I'd like to avoid becoming 'that person' who was severely over-radiated right before they decommissioned a malfunctioning machine.

[DanBC]

Do you drive to the airport?

EDIT: Driving to the airport will expose you to far more risk than walking through the machine, however you define that risk.

[JshWright]

A significant benefit is derived from driving. No such benefit exists from AIT scanning.

[rbcgerard]

What is you confidence level regarding the maintenance and calibration of these machines?

[DanBC]

I have no idea. I do know that driving is far more dangerous how ever you define danger.