Body scanners have 'mutagenic effects'

A Californian university professor of biochemistry said the Obama administration's claim that full-body scanners pose no health risks to air travellers is in "error".

This image of an adult man was taken using a Rapiscan Secure 1000 backscatter x-ray scanner. (Credit: John Wild)

The administration's defence of the controversial machines, which use x-rays to perform what critics have dubbed naked strip searches, has "many misconceptions, and we will write a careful answer pointing out their errors", said John Sedat, a University of California, San Francisco (UCSF) professor of biochemistry and biophysics and member of the National Academy of Sciences.

"Because four people are working on this, it will not be done in one day," Sedat said.

The scanners are being mulled by Australian officials and safety assessments will be conducted by the Australian Radiation Protection and Nuclear Safety Agency.

Earlier this week, the White House's Office of Science and Technology Policy posted a statement saying the x-ray scans are safe because "the issue had been studied extensively for many years" by federal agencies.

That post was a response to a letter (PDF) that Sedat and three other faculty UCSF members sent to White House science advisor John Holdren in April.

Their letter to Holdren said "it appears that real independent safety data do not exist". In addition, the authors say: "There has not been sufficient review of the intermediate and long-term effects of radiation exposure associated with airport scanners. There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations."

Air travellers over 65 years old are especially susceptible to the "mutagenic effects of the x-rays", they say, as are HIV and cancer patients, children and adolescents, pregnant women, and men (because the x-rays can penetrate skin and put the testicles "at risk for sperm mutagenesis"). Eyes could also be at risk because x-rays can penetrate the cornea.

For its part, the administration rejects any health concerns. A letter last month from the FDA and the Transportation Security Administration responding to the UCSF researchers' concerns says "the potential health risks from a full-body screening with a general-use x-ray security system are minuscule."

The x-ray scanners have been used for years, but were turned on this week and are being used as the primary screening technique.

Anyone hoping to opt-out in favour of a manual pat-down may not like what happens. The TSA quietly changed its procedures a few weeks ago to what it delicately calls "enhanced pat-downs", which involve screeners using their fingers — instead of the backs of their hands — to feel the outlines of male or female genitalia.

Via CNET