Are there health risks associated with full-body airport scanners?

The next time Kerry Crofton flies to the United States, she will not go through the full-body scanner at airport security. That’s because the Victoria-based health educator isn’t convinced it’s safe to do so, even though Health Canada says the scanning machines don’t pose any risk to human health.

“I would request a physical pat down,” Crofton—author of the book Wireless Radiation Rescue: Safeguarding Your Family From the Risks of Electro-pollution (Global Wellbeing)—tells the Georgia Straight in a phone interview. “And I would not let a young child go through one of them. There are a lot of health concerns.”

The full-body scanners at Canadian airports—introduced at YVR earlier this year following the same move in the United States to heighten security—use “millimetre-wave technology”.

When a passenger steps into a millimetre-wave scanner, radio-frequency energy is projected over the body. The radio waves  are reflected back to create a three-dimensional silhouette-type image that security staff see on a screen in another room.

Now that the machines are a routine part of international travel, Crofton would like to know who, if anyone, is monitoring the devices—and what health problems might be associated with the machines.

“How are the scanners calibrated?” Crofton asks. “Who’s calibrating them? How consistent are the levels? Who’s monitoring the levels? What long-term data do we have on their use?

“No one wants to see another Air India or shoe bomber”¦but we may be unknowingly exposing people to consistent risk.”

L-3 Communications Security and Detection Systems, the manufacturer of the devices, states on its website that the scanners are harmless. The site explains that the millimetre-wave scanners emit only nonionizing radiation, which is not to be confused with ionizing radiation. The latter is a type of electromagnetic radiation, such as X-rays and the sun’s ultraviolet rays, that can disrupt DNA and cause tissue damage.

The company’s assurances, however, aren’t enough to persuade Crofton that the scanners are safe.

“The misconception is that because this type of scanner is not the same as an X-ray and the waves are much lower and much less powerful, it must be safe,” she says. “On the contrary: there may be significant adverse biological effects.

“Pregnant women are more vulnerable [to health effects],” she adds. “People with pacemakers can be affected.”

Passenger preboard security screening at Canadian airports is the responsibility of the Canadian Air Transport Security Authority. A CATSA spokesperson referred questions to its own and Health Canada’s websites.

“Health Canada has assessed the technical information on this device and concluded that the radio frequency energy emitted by the device is well within Canada’s guidelines for safe human exposure,” Health Canada’s site states. “Only a small portion of the RF energy transmitted by the device is absorbed within a thin layer (1 mm) of the body’s surface.

“To protect the public from any possible health effects associated with exposure to radio-frequency (RF) electromagnetic energy, Health Canada developed a guideline, commonly known as Safety Code 6, which sets safe human exposure limits,” the site says. “The limits specified in this guideline were established after Health Canada scientists reviewed the results of hundreds of studies over the past several decades on the biological effects of radiofrequency energy. Health Canada has set general public exposure limits at 50 times lower than the threshold for potentially adverse health effects.”

According to Crofton, though, those limits are outdated. She says health effects from exposure to radiation are cumulative, and that even low levels can suppress the immune system, disrupt neurological functioning, and have other negative effects.

David Measday, professor emeritus in UBC’s department of physics and astronomy, says that the benefits of the full-body scanners far outweigh the risks.

“Modern jets fly at an altitude where the cosmic-ray radiation is greater than at ground level, but it is not so severe that pilots and air crew are all going down with cancer,” Measday tells the Straight. “So I would personally prefer to have the scanners than have the very real risk of some idiot trying to set off a bomb in my plane.”

According to the U.S. Transportation Security Administration, millimetre-wave scanners emit thousands of times less radiation than a typical cellphone. (Whether cellphone use is harmful to human health is another contentious topic of debate.)

“Advanced imaging technology screening is safe for all passengers, including children, pregnant women, and individuals with medical implants,” the TSA site states.

The TSA notes that the machines have been evaluated by the Food and Drug Administration’s Center for Devices and Radiological Health, the Commerce Department’s National Institute of Standards and Technology, and the Johns Hopkins University Applied Physics Laboratory.

A report by the New York Times, however, found that those evaluations only tested whether the amount of radiation emitted met the guidelines established by the American National Standards Institute, an organization of private companies and government agencies.

Travellers not wanting to pass through the full-body scanners can ask for a physical pat down, just as Crofton plans to.