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Washington, Mar 17 (ANI): The question as to whether airport security scanners pose any threat to the long-term health of human beings has been addressed in two articles.

One type of scanner employs millimetre wave technology, which delivers no ionizing radiation. However, the second type of scanner currently deployed at airports uses backscatter X-rays that expose the individual being screened to very low levels of ionizing radiation.

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, N.Y., said people should be concerned about the long-term consequences of being exposed to a potential radiation-induced cancer risk.

“The risks for any individual going through the X-ray backscatter scanners are exceedingly small,” Brenner said.

“However, if all air travellers 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,” he stated.

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,” he stated.

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), optimisation (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,” 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 optimised,” he stated.

Both Brenner and Schauer agree that the scanners using millimetre wave technology should be considered as a first option, since they are similar in cost and functionality to the backscatter machines, but do not expose the passenger to ionizing radiation.

However, they also say that the average traveller should not be overly concerned about being screened with the backscatter scanners.

“As someone who travels just occasionally, I would have no hesitation in going through the X-ray backscatter scanner,” Brenner said.

“Super frequent fliers or airline personnel, who might go through the machine several hundred times each year, might wish to opt for pat-downs.

“The more scans you have, the more your risks may go up-but the individual risks are always going to be very, very small,” he added.

Both the articles appear in the April issue of Radiology. (ANI)