Frequent Fliers Risk Cancer From TSA Backscatter X-rays; Safer Alternatives Are Available Radiological Researcher Tells Congressional Committee

In his testimony on March 16^th, Prof. Brenner told the Committee on Oversight and Government Reform, Subcommittee on National Security, Homeland Defense & Foreign Operations at the hearing on full body scanners that:

1.Using the most credible dose and risk estimates that we have, one can say that the individual radiation-induced cancer risks associated with a few whole-body x-ray backscatter scans are likely to be extremely small. Our best estimate is that the chance of any given individual developing cancer as a result of the x-ray exposure from a few scans is around 1 in 10 million. Thus it is reasonable to say that, for an average individual, the scanners are “safe”. However, individual lifetime cancer risks will be somewhat higher for children, radiosensitive individuals and, particularly, for aircrew and for very frequent fliers.

2. As well as individual risk, however, from a public-health / policy perspective it is important also to take into account the population risk. This relates to the number of cancers induced in the whole population as a result of scanner use. In that x-ray backscatter scans have become a primary screening measure, very large numbers of people will likely be exposed to very small radiation-associated cancer risks from the associated radiation exposure.  Given the very large numbers of scans involved, potentially up to one billion each year in the US, there is a significant likelihood that, amongst the scanned population, there will be some cancers produced by  the associated radiation exposure. A best estimate is around 100 cancers per year, though this number is quite uncertain.

3.  Given that it is unlikely that the alternative airport whole  body-scanning technology (millimeter wave) will be associated with population cancer risks, from a public health perspective, they may be a preferable advanced whole-body imaging technology. 

4. If there were no feasible alternatives to x-ray backscatter scanners, it could certainly be argued that such population risks would be more than balanced by the associated benefits of reducing the risk of a terrorist event. However, millimeter wave scanners are a feasible and practical whole-body scanning technology which does not involve ionizing radiation, and for which there is currently essentially no mechanistic or experimental evidence of biological risks. Whatever the actual radiation risks associated with x-ray backscatter machines, the ALARA principle clearly implies that a comparable technology which does not involve x rays is a preferable alternative

An image of Susan Hallowell, Director of the Transportation Security Administration’s research lab taken with backscatter x-ray system