Dallas-Fort Worth International Airport is home to eight full-body scanners, up from two a few weeks ago, and it's a security ritual more and more passengers are going through and many accept.
But some passengers, and even some of the largest pilot groups are raising questions not about security, but about safety. Specifically, they're concerned about the effects of the radiation, after all it is an x-ray.
"If you had to pass through this x-ray machine everyday on your way to work, it might raise some concerns. Well that's what pilots are having to do," said Officer Scott Shankland of the Allied Pilots Association.
In response, the Transportation Security Administration loosened requirements for pilots but not passengers, saying the risk is almost non-existent.
"We feel the amount of radiation is so negligible, that it has no impact whatsoever on health," said Luis Casanova of the Transportation Security Administration.
The TSA says going through the full-body scanners amounts to the same radiation as one one thousandth of a chest x-ray. A private physicist found it up to ten times that amount. Or one one-hundredth of a chest x-ray.
Others say the real effects just aren't known because they haven't been adequately studied.
So what's the truth?
Michael D. Story, Ph.D. is an associate professor at UT Southwestern Medical Center in Dallas in the Division of Molecular Radiation Biology, he does research on radiation for NASA.
His overall assessment of the scanners? "The risk in this case for cancer is extremely low. An individual should not be worried about that at all," Story said.
Story said the dosage from the body scanners is at least 200 times less than that a passenger receives during a typical airline flight.
In other words, he says, if you're not worried about the radiation you get flying, you shouldn't be worried about the radiation from the scanner.
At the same time, he says the data just isn't in yet on possible long-term effects on skin cancer among young people.
"There's also concern in the sense that basal cell takes a long, long -- decades -- to develop. So when you put children through a scanner, what are you doing decades later? We don't know that answer yet," Story said.
Others question not the radiation, but whether the body scanners show too much.
Passengers can opt out of the scanners and choose a pat-down instead. But then, there are complaints they've gotten way too personal. The pat-downs also take longer.
And with talk of an organized "opt-out day" this week, the fear is long lines.
"Image technology takes 2 to 4 seconds, where a patdown may require 2 to 4 minutes," said Casanova.
Regardless of the privacy and safety concerns, TSA says every passenger will be screened, no matter how long it takes.
Next year, the full-body scanners will start showing up at Dallas Love Field.
