Much of the debate over full-body airport scanners has been focused on privacy, about the near-naked images the machines produce. But a far more serious debate is about to get underway -- are the scanners even safe?
When two of the largest pilots unions announced a boycott of the scanners last week, they cited two reports that say the machines give off a lot more radiation than the TSA said they would.
The agency previously claimed that being scanned exposes the body to about two minutes worth of cosmic radiation at altitude -- or about 1/1000th of the radiation received from a standard chest X-ray.
But two new studies -- one a Congressional report delivered by Dr. David Brenner, head of Columbia University's Center for Radiological Research, and a separate study by Peter Rez, a professor of physics at Arizona State University, claim those estimates were 5 to 20 times too low. They say the actual risk was probably close to 10 to 20 minutes worth of high altitude cosmic radiation exposure -- about a 1/50th to 1/100th of a chest X-ray's radiation dosage. Both experts agree that children and frequent fliers are at the greatest risk, and that the cancer risk is concentrated on the skin.
"If you think of the entire population of, shall we say a billion people per year going through these scanners, it's very likely that some number of those will develop cancer from the radiation from these scanners," Dr. Brenner told CNN.
The TSA, while not disputing those findings, still defends the machines. "TSA sets strict standards for all of its technology to include detection capabilities, operational capabilities and health and safety standards."
Rez said for the average passenger, the risk of dying from body-scanner induced cancer is about equal to the risk of dying from a terrorist attack -- 1 in 30 million. "They're both incredibly unlikely events. There's still a factor of 10 lower than the probability of dying in any one year from being struck by lightning in the United States."