A new report from Pro Publica – the non-profit journalism site – says that the millimeter wave body scan machines which make up about half of all the body scanners used by the TSA at airport security checkpoints may have a high rate of false alarms.
Health Concerns vs. False Alarms
These wave machines are not to be confused with the TSA’s X-ray body scanner, which have been linked to health concerns and are currently banned by the European Union.
The millimeter wave machines use electromagnetic waves that have not been associated with any particular problems at all until the current “false positive” situation that Pro Publica says can sometimes “cause the scanner to mistake [human] sweat for a potentially dangerous object.”
It’s important to note that this report focuses on millimeter wave machines in European nations. According to the reporters, it’s difficult to compare the rate of false alarms recorded by the U.S. X-ray machines vs. millimeter wave machines since that agency keeps such figures under wraps in the interest of national security, but information gleaned from European airports seems fairly startling:
“In Germany, the false positive rate was 54 percent, meaning that every other person who went through the scanner had to undergo at least a limited pat-down that found nothing.” –Pro Publica, 12-19-11
More Millimeter Wave Machines to U.S. Airports
Neither Canada or the Netherlands reported problems with false-positives on their millimeter wave machines, and the U.S. meanwhile is expected to add another 300 or so of these scanners to domestic airports by the spring of 2012.
Although both types of these machines were initially quite controversial in the U.S. due to images that some likened to ‘naked pictures’, new software in many machines reveals only a cookie cutter-type outline, and there has been a corresponding drop in complaints about the TSA.