For their study, published online March 28 in the Archives of Internal Medicine, Smith-Bindman and Mehta looked at three groups: all fliers, frequent fliers (those who fly 60 or more hours a week) and 5-year-old girls who fly weekly. This last group was included because children are more sensitive to radiation.
They assumed that all passengers would have a full-body scan on each trip, receiving radiation exposure of 0.1«Sv (microsievert), with 100 million passengers taking 750 million flights in a year.
Among passengers on all these flights, they estimated that six cancers could develop over a lifetime from scanner radiation. But, some 40 million cancers would result from other causes in those fliers, the authors say.
For frequent fliers, four cancers might be linked to these scanners, but 600 cancers would result from flying at high altitudes, and 400,000 cancers would develop because of other factors, the researchers noted.
Among 2 million 5-year-old girls making one round-trip a week, airport scanners might cause one additional breast cancer over their lifetimes, but 250,000 breast cancers would result from other causes in this group, the researchers said.
"Based on what is known about the scanners, passengers should not fear going through the scans for health reasons, as the risks are truly trivial. If individuals feel vulnerable and are worried about the radiation emitted by the scans, they might reconsider flying altogether since most of the small, but real, radiation risk they will receive will come from the flight and not from the exceedingly small exposures from the scans," Smith-Bindman and Mehta write.
Still, they note that additional testing of the devices would be prudent.
Another expert, Dr. Stephen Machnicki, associate chairman of the department of radiology at Lenox
All rights reserved