The Health Effects of Airport Security Scanners

Published 17 March 2011 by HomelandSecurityNewswire and reprinted with their permission. We bring this up (as we have previously) as older travelers have had more exposure to radiology than younger travelers and cumulative effects can be more cause for concern.

The Transportation Security Administration (TSA) has begun to use whole-body imaging scanners as a primary screening measure on travelers passing through airport security checkpoints; one type of scanner employs millimeter wave technology, which delivers no ionizing radiation; the second type of scanner currently deployed at airports, however, uses backscatter X-rays that expose the individual being screened to very low levels of ionizing radiation; what are the health implications of these scanners? Two prominent radiologists offer answers

The Transportation Security Administration (TSA) has begun to use whole-body imaging scanners as a primary screening measure on travelers passing through airport security checkpoints. One type of scanner employs millimeter wave technology, which delivers no ionizing radiation. The second type of scanner currently deployed at airports, however, uses backscatter X-rays that expose the individual being screened to very low levels of ionizing radiation. In the April issue of Radiology, two articles address the question of what potential long-term public health threats, if any, these backscatter X-ray systems pose.

Eureka reports that in the first article, David J. Brenner, Ph.D., D.Sc., director of the Center for Radiological Research at Columbia University Medical Center in New York, proposes that from a public health policy perspective, given that up to one billion such scans per year are now possible in the United States, we should have concerns about the long-term consequences of an extremely large number of people being exposed to a potential radiation-induced cancer risk, no matter how slight.

“The risks for any individual going through the X-ray backscatter scanners are exceedingly small,” Dr. Brenner said. “However, if all air travelers are going to be screened this way, then we need to be concerned that some of these billion people may eventually develop cancer as a result of the radiation exposure from the X-ray scanners.”

In the second article, David A. Schauer, Sc.D., C.H.P., executive director of the National Council on Radiation Protection and Measurements (NCRP), argues that the summation of negligible average risks over large populations or time periods into a single value produces a distorted image of risk that is out of perspective with risks accepted every day, both voluntarily and involuntarily.

“There is no scientific basis to support the notion that a small risk to an individual changes in any way for that individual as others around him are also exposed to the same source of radiation,” he said. “Critics of security screening acknowledge that doses from backscatter X-ray systems are very low and safe for an individual.”

Dr. Schauer advocates strict regulatory control of the backscatter scanners in order to ensure that their use is consistent with the goals and objectives of radiation protection, which include justification (benefits exceed cost or harm), optimization (exposures are kept as low as reasonably achievable) and limitation (individual doses are limited).

“Any decision that alters the radiation exposure situation should do more good than harm,” Dr. Schauer said. “In other words, people should only be exposed to ionizing radiation for security screening purposes when a threat exists that can be detected and for which appropriate actions can be taken. In addition, exposures must be justified and optimized.”