Transportation Security Administration Not Trying to Kill You: Why There's No Reason to Fear Radiation Exposure

Driving the panic over the government's new body-scan policy is a deep-seated worry about radiation. Dr. Kent Sepkowitz on why there’s nothing to fear but fear itself.

Every Thanksgiving, air travelers are met with a new crisis, a new threat to their well-being, a new reason to stay home and call in the chicken with cashews in brown sauce. In recent years, we have seen terrorist threats and ominous cold fronts, air-traffic control computer screwups and the swine-flu infection sure to strike any traveler with the swiftness of Black Death.

This year’s theme is a bit different—because this year, our panic is self-induced. In our ongoing program to keep fear alive, the Panicked Citizen Cooperative of America has presented us with the latest non-issue: the airport scanner. Big, metallic, hulking, faintly foreign: No sir, you aren’t firing that at my children. This one is particularly potent because it provides a two-for-the-price-of-one special for the veteran paranoid: Not only is the government irradiating me, but they are measuring my package as well. My scanned homunculus, dick and all, surely will appear online then go viral. PLUS they will cause cancer in me. They surely will. (Added weirdo bonus—the TSA guy might goose me).

The time is surely ripe for this specific concern. Well-founded consumer anxiety recently has arisen over the overuse of the CT scanner, a test that can have real radiation consequences. This week, The New York Times focused on the issue of possibly unwarranted dental X-rays, especially in children. This too is worth the worry. The airport scanner issue folds nicely into the theme—they are all X-rays, right? And who but the truly frightening (i.e., physicists) can keep all of this straight—gamma rays and ionizing radiation and DNA repair and enzymes. It’s enough to make a guy run screaming into the high school hallway.

There actually is a radiation risk when a person flies from here to there; it is not, however, from the scanner but rather from the flight itself.

But calm down please. We do not need to revisit the clammy atelier of science class. This one is easily debunked by simple facts—assuming there are a few reality-based Americans still around. Rational people—these guys are physicists for Christ’s sake, remember?—have been all over this issue for more than 40 years, when the fears about radiation from television sets first surfaced. They even formed a group—the National Council on Radiation Protection & Measurements (—to monitor the problem without interference from Mr. Big Brother, aka, Plus check this picture out. Is this guy part of a sinister plot to prevent Americans from learning of their risk?

The physicists and nuclear safety specialists measure risk using something called the “sievert” (previously, they used the “gray”). A single sievert represents a specific amount of radiation and allows comparison of relative risk, sort of like the US dollar and international monetary policy. Sort of. Using the sievert, the risk for example of an airport scanner can be accurately and precisely compared to the risk of a chest X-ray or a CT scan or residence in Hiroshima in 1945. It is not confusing or misleading or complex. In fact, it is the simplest arithmetic imaginable.

The results are in on scanners and have been for a long while. They are available in countless places, including in today’s New York Times, Wikipedia’s section on exposure, the American College of Radiology website, and the government’s own websites (and here). Here are the facts: A routine chest X-ray gives between 100 and 1,000 times the radiation exposure of an airport scanner. Furthermore, the radiation exposure from a CT scan is 10 to 20 times that of a chest-X-ray and therefore thousands-fold more than a pass through an airport scanner. And annual mundane living on this earth with the various natural (and less natural) sources of radiation exposure constitutes the equivalent of 25 to 50 chest X-rays per year, or tens of thousands of times the dose of the airport scanner. In other words, folks, the airport scanner is not even sort of worrying.

Given how basic and non-inflammatory the facts, why all the inflammation? Maybe it’s just what happens when the holidays approach and we all begin to sweat over seeing Uncle Herb once again. Because there truly is no cancer risk, no conspiracy (and I am a big grassy knoll fan, believe me), no government wants-to-fry-my-brain-and-gonads-so-I’ll-support-Obama’s-socialist-policies threat. This one is not even close.

One last point: There actually is a radiation risk when a person flies from here to there; it is not, however, from the scanner but rather from the flight itself. The sun, as it turns out, is spitting out more harmful radiation than airport scanners ever thought about. Once we are up and away from the earth’s protective atmosphere and a mile up, the sun’s ultraviolet rays do indeed hit us. For the record, the flight itself results in 100 to 1,000 times more exposure than the scanner that got you onto the plane. Thankfully for us all, facts indeed are stubborn things.

Kent Sepkowitz is an infectious disease specialist in New York City. He has contributed to The New York Times, Slate, and, oh-so-briefly, O Magazine. He also writes academic medical articles that are at times pretty tough sledding.