That sentence was there for the benefit of people with safety questions about the scanners. For more information on the medical uncertainties, follow the link labeled "completely safe" to the Archives of Internal Medicine article and look under "Related Article".
The post concludes on an entirely unrelated point to the premise of the post
|Anybody can opt out of the body scanner for a pat-down.
Sure, I'm carrying in a gun in my shirt pocket I'd like to get on the plane. Let me just request the patdown to make sure I get caught.