Full-body airport scanners have been controversial since their introduction. Opponents typically cite two issues with the technology: they are too revealing and they could pose a radiation risk. Now, new findings could ease one of these concerns, but will it be enough?

Researchers at the University of California, Berkeley have published a study of airport scanning devices and have concluded that the types of machines using x-ray technology emit nearly negligible levels of radiation compared to other sources. According to a report published in the Archives of Internal Medicine of the American Medical Association, "the backscatter x-ray scanner, the type used more commonly in the United States, uses very low dose x-rays, similar to those used in medical imaging." Backscatter technology is one of two being used at airports around the world. The other types of machines rely on millimeter wave technology and do not emit any radiation. Still, the debate continues over the use of full-body scanners.

The safety concerns have been particularly raised by frequent flyers, mostly flight crews. Many crew members have been advised by their unions to avoid being scanned by the machines in question over fears of the cumulative effects of multiple exposures. According to the report, radiation at low doses can damage cells but the body is able to repair them quickly. At moderate to high doses, the effects are more detrimental.

To keep things in perspective, the researchers state that the radiation emitted by these backscatter x-ray scans is "exceedingly low." In fact, flying at high altitudes exposes an individual to the same amount of radiation, only for much longer periods. The net effect of going through a body scanner adds a trivial amount of additional exposure.

For its part, the U.S. Transportation Security Administration (TSA) says it is committed to testing its machines throughout the year to ensure that public concern is eased, especially after some inaccuracies were discovered in earlier safety reports. This prompted the agency to retest all of its machines – a process to be completed by the end of March. Despite any assurances to the contrary, the concern over malfunctioning machines remains. What happens if a machine malfunctions or needs calibration? According to a TSA spokesperson, the scanners are routinely tested by the manufacturer and various institutions.

TSA assurances and scientific findings aside, it's still not clear what conditions and scenarios were used in the latest studies. It's also unclear if the TSA is testing their machines in real-time at busy airport peak times. Knowing how the tests were conducted could go farther in easing the minds of the flying public than simply declaring a device safe. Hopefully, we'll have those answers sooner than later.