Is airport security exposing you to too much radiation? It’s a fair question.
The Transportation Security Administration (TSA) recently posted test results regarding radiation emitted from some passenger and luggage screening equipment. The reports included calculation errors, missing data, and anomalies, prompting the TSA to announce it will retest all radiation-emitting full-body scanners and other baggage screening equipment that had inaccurate reports.
Is the TSA doing all it can to protect the flying public and airport employees from radiation exposure… and are we receiving accurate information?
Senator Susan Collins (R-ME), Ranking Member and former Chairman of the Homeland Security and Governmental Affairs Committee, which has jurisdiction over the Department of Homeland Security, issued a statement earlier this week:
“Administrator Pistole and I have discussed at length the full-body scanners, and TSA has repeatedly assured me that the machines that emit radiation do not pose a health risk. Nonetheless, if TSA contractors reporting on the radiation levels have done such a poor job, how can airline passengers and crew have confidence in the data used by the TSA to reassure the public? More than one in four reports — randomly selected from thousands of reports over two years and covering 15 airports — included gross errors about radiation emissions. That is completely unacceptable when it comes to monitoring radiation.”
According the TSA blog, manufacturers and/or third party maintenance providers are required to test screening devices for radiation before they leave the factory, and again after being installed at an airport to confirm that radiation levels are within applicable standards. More tests are performed after maintenance or relocation.
In an effort to reassure the flying public, the TSA blog states:
“By conducting ongoing radiation tests throughout the life of the technology, TSA is going above and beyond regulatory standards to ensure passengers and operators are not being exposed to excessive radiation doses.
“To increase our transparency — and to let you see for yourself that the technology is safe — we will be posting all future radiation reports online. You can see where they’ll be posted here.”
The TSA reports some inaccuracies in recent contractor reporting that included:
- Lack of notation for the latest calibration date for the machine being tested or the most recent calibration date noted had expired on survey meters
- Information missing regarding warning labels and other required labels on machines
- Calculation errors not impacting safety
- Missing survey point readings (e.g., If the test procedure required 13 points around the machine to be tested, in some cases, readings for only 11 points were reported)
- Inconsistent responses to survey questions
- No reading of background radiation noted
- Missing other non-measurement related information
Maintaining that none of this impacts the assessment that the technology is safe, the TSA still calls this “unacceptable,” putting new protocols in place:
- Requiring re-testing of all backscatter advanced imaging technology units in airports, as well as all technology with inaccurate reports, by the end of March 2011
- Requiring contractors to re-train personnel involved in conducting and overseeing the radiation survey process
- Requesting the National Institute for Occupational Safety and Health (NIOSH) re-evaluate TSA’s safety program and update its 2008 report
- Expanding an existing partnership with the U.S. Army Public Health Command to conduct additional independent radiation surveys and radiation safety compliance audits at airports equipped with X-ray based technologies
- Increasing TSA oversight on the overall radiation survey and documentation process
- Ensuring all appropriate contractual remedies are considered and implemented, as necessary, in the event that radiation inspections are incomplete or delinquent
- Every machine using X-ray technology that is deployed in an airport will have a new radiation test conducted within the next 12 months
Administrator Pistole has also directed TSA to commission an independent entity to evaluate these protocols.
Sources of Radiation
- One year of naturally occurring background radiation: 300 millire
- Annual recommended limit to the public of radiation from man-made sources: 100 millirem
- Chest X-ray: 10 millirem
- Flight from New York to Los Angeles: 4 millirem
- One day of natural background: 0.1 millirem
- Drinking three glasses of water a day for a year: 0.045 millirem
- One backscatter X-ray scan: Approximately 0.005 millirem
Source: TSA: “Radiation dose comparisons from the Health Physics Society and other safety experts.”
Two articles in the April issue of Radiology address the potential long-term public health concerns of airport security.
David J. Brenner, Ph.D., D.Sc., director of the Center for Radiological Research at Columbia University Medical Center in New York, N.Y.:
“The risks for any individual going through the X-ray backscatter scanners are exceedingly small. 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.”
David A. Schauer, Sc.D., C.H.P., executive director of the National Council on Radiation Protection and Measurements (NCRP):
“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. Critics of security screening acknowledge that doses from backscatter X-ray systems are very low and safe for an individual.
“Any decision that alters the radiation exposure situation should do more good than harm. 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.”
Radiation and Cancer
Ionizing radiation is a proven human carcinogen. Most studies on radiation and cancer risk have looked at people exposed to very high doses of radiation. It is harder to measure the increase in cancer risk that may come from much lower levels of radiation exposure.
Most scientists and regulatory agencies agree that even small doses of ionizing radiation increase cancer risk, although by a very small amount. In general, the risk of cancer from radiation exposure increases as the dose of radiation increases, but there is no threshold below which ionizing radiation is thought to be totally safe. (Source: American Cancer Society)
Photo Credit: TSA