January/February 2010

More full-body scanners coming to airports near you

Since explosive materials were sneaked onto a U.S.-bound flight from Amsterdam on Christmas Day 2009, full-body scanning machines are more likely to make their way to security lines at your local airport, even though they might not have detected said materials.

While the Transportation Security Administration already has 40 such devices in place, it bought 150 in January to be placed in U.S. airports and said it plans to buy 300 more (they go for $170,000 apiece).

These full-body scanners fall into two main categories: millimeter wave and backscatter, according to CNET. The first directs radio waves over a body and measures the energy reflected back to render a 3D image. The latter is a low-level X-ray machine that creates 2D images.

The scanners are supposed to be the high-tech (and energy-inefficient) version of a pat down, and can detect items such as nonmetallic weapons and explosives not picked up by metal detectors.

Millimeter wave scanners produce 30 to 300 gigahertz electromagnetic waves, and reveal explosives if they are denser than other materials. This means these scanners emit less radiation than a typical cell phone, according to TSA.

The backscatter machines are low-level X-ray machines that expose bodies to as much radiation as about two minutes of flying in an airplane does. In other words, if you use a cell phone and you fly, you are already exposing your body to more radiation than these scanners will.