Do airport full-body scanners pose any health risks?
Wendy Tao, B.Sc., Student Representative
Airport full-body scanners, friend or foe?
A lot of attention has been given to the use of the full-body scanners in airports recently and I wonder if they pose any real risks to human health. There are two types of full-body scanners. One is a millimeter wave scanner, which uses radio frequency and the other is a backscatter scanner, which uses very low levels of X-rays.
The consensus among radiation experts and medical physicists on the health risks of backscatter scanners is a mixed bag. According to Kelly Classic, a health physicist at the Mayo Clinic, the amount of radiation from one full-body airport scan is equivalent to two minutes of flying in an airplane, to sleeping next to another person for the night, and to 40 minutes of just living which is almost insignificant. On the other hand, a group of scientists from the University of California San Francisco (UCSF) are concerned about the potential serious health risks of the full-body scans. They point out that the device has not been adequately tested on older passengers, pregnant passengers, and passengers with HIV or cancer, and what low doses of radiation might have on breast tissue directly beneath the skin, on corneas, and on testicles. Since then, John Hopkins’ applied physics lab tested the most commonly used machine and found the doses of radiation delivered to a person standing in the scanner are well below those laid out by the American National Standards Institute (ANSI). Nonetheless, the scientists from UCSF states that at the entry and exit points where the radiation dose could exceed the per year dosage set by ANSI. In addition, Peter Rez, PhD, professor of physics at Arizona State University questions the radiation testing results from the John Hopkins scientists. He also worries that the real risk posed by the machines is if they jammed and failed to turn off which potentially could deliver a dose of radiation that is millions of times higher than intended. The machines do have fail-safe methods built in but there are no engineering studies proving the fail-safes are reliable.
According to the Transportation Security Administration (TSA), the backscatter scanners which emit low levels of ionizing radiation are now deployed in 70 of the 450 airports in the U.S. Fortunately, this type of scanner is not used in Canadian airports. 36 full-body non-ionizing radiation millimeter wave scanners are deployed in Canadian airports instead. As indicated on Health Canada website, the millimetre-wave body scanner works by projecting low-level millimetre-wave, radio-frequency (RF) energy above and around the passenger's body. They state that the scanner do not pose a risk to human health since 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. However, as most of us know, mobile phones and microwaves also emit non-ionizing radiation and most conventional health experts believe they do not post any health risks which I’m sure this topic will generate a heated debate within the naturopathic community. I guess the verdict is out there. Personally, I will definitely opt out of the full-body scanners if I happened to be picked for the machine.