Some major airports are getting rid of the full-body x-ray scanners many air travelers have to go through before clearing security.

The so-called "backscatter machines" have been removed from JFK, Orlando, O'Hare, Boston-Logan and LAX, to be replaced by millimeter-wave scanners that show a generic cartoon image of your body. Former National Transportation Safety Board chairman Mark Rosenker says the x-ray machines emit low levels of radiation, but that still worries some," There are still certain areas of the scientific community that do believe any type of radiation touching the human body can create cancer," he says.

The TSA denies safety and privacy prompted the change. They say it's for efficiency, not safety, reasons.

The backscatter machines have been under fire since the TSA began installing them following the 2009 underwear bomb incident. Rosenker says the old machines won't be junked, "They're going to take these backscatter machines, because it is laborious, it does take more staff, " he says.  "It does take more time, and they'll take it to airports where there's a small traffic pattern."

The new machines use low energy radio waves like in your cell phone.