Regardless of the politics around the TSA Body Scanners, the amount of radiation one is exposed to is a serious concern. Now, as we hear talk of the elimination of the ‘pat-down’ option, it seems the average commuter will be forced to undergo radiation exposure.
Although the supposition is that the amount of radiation one is exposed to is safe, there are dissenting voices in the science world. While some opponents to the scanners cite a lack of long-term studies on the specific technologies, others claim there is simply not enough information to know whether real damage is being done.
As Douglas Boreham, Professor in Medical Physics and Applied Radiation Sciences at McMaster University in Ontaria, CA stated, “I don’t think the right questions have been asked. We don’t have enough information to make a decision on whether there’s going to be a biological effect or not.”
While most Americans understand the technology in terms of being an x-ray machine, the truth is the Body Scanners utilize two new technologies. One is called Millimeter Wave Scanning and the other is called Backscatter x-ray.
Millimeter Wave Scanning technology was invented in 1992. While it is said the radiation emitted does not penetrate deep enough into the body to disrupt cells, there is evidence countering that. Millimeter Wave Scanners emit a wavelength of ten to one millimeter called a millimeter wave. These waves are considered Extremely High Frequency (EHF) and are known as tetrahertz (THz) radiation, Research has shown that tetrahertz radiation can ‘unzip’ double-stranded DNA. These DNA breaks are what lead to problems with gene expression as well as DNA replication. This is a concern in terms of birth defects as well as cancers.
As one study on Millimeter Wave Scanning from a 2011 published article in the International Journal of Microwave Technology states, “It is therefore plausible that distribution of the molecular products of thermal injury to areas remote from the site of irradiation could cause secondary injury (including, conceivably, carcinogenesis) and this is still an active area of research.”
Backscatter X-ray Technology was also invented in 1992 and utilizes ionizing radiation to take a 2D image. Ionizing radiation breaks chemical bonds and is known to be carcinogenic in even minute doses. While the amount of radiation exposure during the Body Scan is considered by proponents to be negligible (they claim 1 million people being scanned 520 times in one year would only increase cancer rates by 4 cases), opponents to the Technology are many.
Several scientists from University of California in SF, among them an expert in cancer and imaging, wrote a letter to the Presidential Science Advisor raising questions regarding the safety of the radiation exposure from these machines. The scientists’ main concern being that the devices are not considered medical, therefore they are not subjected to the same standards by the FDA as medical x-ray devices would be. This is why the scientists claim that the amount of radiation one is exposed to during a Body Scan using this technology is not the amount proclaimed by the authorities.
Apparently, Physics Professor Peter Rez from Arizona State University, shares the same concerns as the UCSF scientists. A paper he authored, soon to be published in the Journal of Radiation Protection and Dosimetry, states that the radiation dose delivered per body scan is a tleast “10 times higher” than what is being reported.
With so many concerns regarding human exposure to these various types of radiations, and so many questions unanswered, it would seem that common sense would dictate these x-ray technologies would be looked into more carefully before mandating an entire population -including pregnant women and children- be exposed to them.