Amputees worry about airport security screening health risk.  

People with prosthetic limbs complain about the CastScope, a screening device, that uses backscatter X-ray technology to identify security threats concealed in a prosthetic, cast or bandage. They are correctly concerned about radiation exposure, the length of time it takes to be screened and a lack of qualified personnel operating the devices.

Much mystery and controversy still surrounds the airport security dose.  X-rays are short wavelength high energy photons that occupy the upper region of the electromagnetic spectrum.  Terahertz/mm-wave scanners use radiation below visible and just above microwaves.