Screening with a metal detector involves walking through a scanner, which uses low-frequency electromagnetic waves to scan for metal weapons and other threats. Metal detector scanners do not use X-ray technology, so they don't emit radiation. The levels of electromagnetic waves emitted by these machines are so minuscule they are considered safe for everyone. The chances of a metal detector harming you or your unborn child are slim to none. Electromagnetic waves are emitted by many devices you use on a daily basis, including your television, curling iron or anything else that uses electricity.