Those new airport scanners do give you a dose of radiation, but a new study says it likely won't be enough to significantly raise the risk of getting cancer.
"Passengers should not fear" the new scanners, said an article published this week in Archives of Internal Medicine. Nearly 500 of the full-body X-ray machines, called backscatters, have been rolled out by the Transportation Security Administration at 78 airports as the latest weapon against airborne terrorism. They use ionizing radiation, a known carcinogen, to identify hidden items.
The cancer risk from exposure to the backscatter scan, which takes only a few seconds, contributes less than 1% of the radiation dose a flier would receive from cosmic rays during the actual flight, according to researchers at the University of California San Francisco. They found that even frequent fliers are unlikely to face any increased cancer risk.
For every 100 million passengers who take seven flights per year, there may be six extra cancer deaths over a lifetime.
“A lot of people are fearful of radiation, and I think they need to be conscious that all radiation is not the same,” says study author Dr. Rebecca Smith-Bindman, a California radiologist. “I don't think the risk is worth us worrying about because it is so low.”
The TSA says the devices are safe for all passengers, including children and pregnant women.
“I think one of the main issues with this paper is that it took doses direct from the manufacturers data, but in other recent publications doses were estimated based on the actual x-ray backscatter images that the machine produces and were higher,” Brenner said.
Earlier this month, the TSA said it would retest each of its machines after maintenance records showed some emitted more than 10 times the amount of radiation expected. The TSA later said the discrepancy was due to "math mistakes" and improperly entered data.