The invasion of privacy posed by airport security scanners might prove too much for some travellers, according to one civil rights advocate. (CBC)

The introduction of full body scanners at Canadian airports raises difficult questions about privacy, cultural sensitivity and personal freedom, according to the B.C. Civil Liberties Association.

"This is a machine that essentially views you naked. It sees through your clothes," the association's policy director, Micheal Vonn, said Tuesday.

The fact that passengers' faces are blurred as they pass through the machine is little consolation, according to Vonn.

"That's like saying you need to run naked through this room but you can put a bag over your head," she said.

The airport scanning technology that will be installed at major Canadian airports over the next two months reveals detailed images of everything from breasts and genitalia to surgical implants and cosmetic enhancements.

Could prevent some from flying

The system allows a screening officer to see whether someone is carrying plastic explosives or other dangerous items.

The scanners will not be used on minors and only on passengers selected for secondary screening, the federal government said Tuesday.

But Vonn said concerns that security personnel of the opposite sex could be looking at their image might prevent some adults from travelling by air at all.

"People whose religious beliefs include a perspective on bodily modesty that would simply preclude them from being in a situation where they could be viewed naked by people they don't know," said Vonn.