TSA on X-Ray Machines: They’re Safe

There has been controversy surrounding the TSA’s use of body scanners in airport security, in part due to questions about the safety of radiation emitted from the machines. The TSA recently published some data on the radiation safety levels of their x-ray equipment.

There’s been a lot of controversy surrounding the TSA’s use of its advanced imaging technology backscatter scanners (a.k.a. full body scanners) in American airports, particularly in light of the busy holiday travel season.

Privacy concerns have been a big part of the controversy, but passenger safety with regards to radiation levels emitted from the machines has also been called into question.  According to a recent post on the TSA’s blog, the radiation levels emitted by all of the x-ray equipment the TSA uses are within government safety guidelines.

When deciding to use a new imaging technology, the TSA states that it develops procurement specifications that are within national radiation safety guidelines  and ensures that bidding manufacturers meet those guidelines either through third party testing or by tests conducted by the TSA.  It applies these standards to any equipment that it plans to use, whether by the travelling public (such as for the body scanners) or by TSA employees (in the case of scanners for checked baggage). Upon verification of those test results, the manufacturer then must conduct its own tests on each individual unit before it leaves the factory.

Regular preventative maintenance checks and radiation safety tests are conducted at least once every 12 months, after any incident that may have damaged the equipment, or at the request of any TSA employee. The TSA also states, “When the technology operates as designed, the dose to any member of the general public, system operators, or other employees falls well below the national standard for safety.”

The TSA has also partnered with the US Army Public Health Command (Provisional) to conduct independent radiation surveys to further validate the TSA’s own test results.  In the last two years, Health Physicists from this organization have conducted surveys of 437 checked baggage systems at 34 airports and have confirmed the radiation safety levels of the equipment.  However, no mention was made in the TSA’s blog post as to whether or not this organization has or will be conducting safety tests on the backscatter (full body) scanners.

According to the TSA web site, the advanced imaging technology scanners began to be deployed for use in airports beginning in 2007.  There are currently 385 imaging units at 68 airports.  The TSA uses two types of imaging units: backscatter and millimeter wave (the latter pictured at right).  The backscatter units use low-level X-rays to create a reflected image of a passenger’s body on the unit’s display monitor. These are the controversial machines as they purportedly show fine-grained anatomical details of the body being scanned.  The millimeter wave machines use electromagnetic waves to create a 3D black and white image.

As for safety of these two types of machines, the TSA’s web site states that “Millimeter wave technology emits thousands of times less energy than a cell phone transmission” and that “One backscatter technology scan produces the same exposure as two minutes of flying on an airplane.”  The web site also states that “Backscatter technology was evaluated by the Food and Drug Administration’s (FDA) Center for Devices and Radiological Health (CDRH), the National Institute for Standards and Technology (NIST), and the Johns Hopkins University Applied Physics Laboratory (APL). All results confirmed that the radiation doses for the individuals being screened, operators, and bystanders were well below the dose limits specified by the American National Standards Institute (ANSI).”

The TSA cites a great deal of research to tout the safety of the new x-ray machines it is using for airport security. You will have to reach your own conclusions about whether or not these machines meet your own personal safety standards, but one thing is clear – they appear to have become a routine part of air travel security procedures.

About the Author

Ian Smith is one of the co-founders of FedSmith.com. He has over 20 years of combined experience in media and government services, having worked at two government contracting firms and an online news and web development company prior to his current role at FedSmith.