Are Airport Security Scanners Actually Safe? We Still Don’t Have a Clear Answer
With the holiday travel season in full swing, millions of Americans will pass through airport security—and many will step into full-body scanners without a second thought. These scanners, officially called advanced imaging technology (AIT), have been a routine part of TSA screening since 2009. They were introduced after the “underwear bomber” incident that same year, when a passenger hid explosives in his clothing on a flight to Detroit.
Yet despite their widespread use, AIT scanners were rolled out with very little transparency. Most travelers don’t realize that there has been no meaningful long-term study proving their safety, and very limited evidence that they prevent terrorism. As a health-focused practitioner, I can’t ignore this imbalance. I’ve opted out of body scanners for years, not because I fear flying—but because the benefits of this technology still aren’t clearly established, while the risks remain uncertain.
A Brief History of TSA Scanning Technology
When AIT first arrived in airports, two types of scanners were used:
• Backscatter X-ray scanners, which use low-dose ionizing radiation—the same type of radiation used in medical imaging, capable of damaging DNA.
• Millimeter-wave scanners, which use high-frequency, non-ionizing electromagnetic waves (more like microwaves).
Backscatter machines quickly drew criticism from radiologists, medical researchers, and privacy advocates. Although the radiation dose was considered low, many experts argued that any exposure to ionizing radiation without medical necessity should be avoided. The European Union banned them, and the TSA eventually removed them in 2012, partly due to privacy-related software issues.
Today, all U.S. airports rely on millimeter-wave scanners, which do not use ionizing radiation and therefore sidestep the biggest health concern linked to the older models. But that doesn’t necessarily mean the technology is risk-free.
Do Body Scanners Actually Make Us Safer?
Despite the billions of dollars spent on AIT, the evidence of its effectiveness remains surprisingly thin. TSA’s own public reports rarely credit body scanners with catching significant threats. Independent investigations have shown high false-positive rates—one German study found the scanners flagged innocuous things like sweat more than half the time. Security researchers who obtained an old backscatter scanner demonstrated that weapons could still be smuggled through and that the machine was vulnerable to tampering.
To date, no known act of aviation terrorism has been stopped because of AIT scanners. Even government analyses estimate the chance of being on a flight with a terrorist incident to be less than one in 10 million. Despite this, the TSA continues to defend the technology, mainly by claiming it “deters attackers”—a benefit that is impossible to objectively measure.
So What About the Health Concerns?
Millimeter-wave scanners emit non-ionizing radiation in the microwave range—similar to cell phones, Wi-Fi routers, and radar equipment. According to international safety guidelines, the radiation dose from a single scan is low, and only a fraction of the allowable public exposure limit.
But here’s the important nuance: Non-ionizing radiation is not completely understood. It can cause heating at the tissue level. Some laboratory studies suggest biological effects are possible under certain conditions. And importantly, we do not have long-term human studies on repeated exposure over decades.
Even the World Health Organization acknowledges that the long-term safety of millimeter-wave devices cannot be definitively confirmed yet. Meanwhile, the International Agency for Research on Cancer classifies radio-frequency radiation—including that from cell phones—as “possibly carcinogenic.” That doesn’t mean it is harmful, but it means we don’t have enough evidence to rule out risk.
In short: There is no proof that airport scanners cause long-term harm. There is also no proof that they don’t.
Putting the Risk Into Perspective
Americans today are surrounded by non-ionizing radiation—cell phones, routers, Bluetooth devices, smart home electronics. Airport scanners add yet another source of exposure, however small. So the real question becomes: Is the added exposure worth it? Especially when the scanners’ effectiveness in preventing terrorism remains unproven.
Statistically, Americans are millions of times more likely to die from heart disease or cancer than from a terrorist attack. Given this reality—and the absence of long-term safety data—I personally continue to opt out of full-body scans.
You might consider doing the same.