Full-body scanners used to secure airports, about 1,000 of which will be deployed across the United States by year's end, do not pose health risks, a study released Monday found.
The University of California study appearing in the "Archives of Internal Medicine" found that a traveler would have to go through a body scanner 50 times to receive the same amount of radiation as from a dental X-ray.
The researchers also said a lung X-ray was equivalent to 1,000 trips through an airport scanner, while a mammogram delivers as much radiation as passing through such a scanner 4,000 times.
The study focused on x-ray machines dubbed "backscatter" which use low-dose x-rays, similar to those used in medical imaging. So far there are some 486 full-body scanners in place in 78 US airports.
"The radiation doses emitted by the scans are extremely small; the scans deliver an amount of radiation equivalent to 3 to 9 minutes of the radiation received through normal daily living," the authors wrote.
And "since flying itself increases exposure to ionizing radiation, the scan will contribute less than one percent of the dose a flyer will receive from exposure to cosmic rays at elevated altitudes," they added.
"The estimation of cancer risks associated with these scans is difficult, but using the only available models, the risk would be extremely small, even among frequent flyers. We conclude that there is no significant threat of radiation from the scans," they wrote.
Advanced imaging technology X-ray scanners currently in use at airports around the United States sparked an uproar among travelers because they produce a graphic image of a person's naked body, genitalia and all.
Others have worried the scans might be unsafe.