In the aftermath of the foiled “underwear bomber” attack on Christmas Day, there’s a major push to install whole-body X-ray scanning machines at airport screening areas. It’s being led by former Homeland Security Chief Michael Chertoff, now a paid consultant for a manufacturer of these X-ray machines. He’s calling for their “large-scale deployment.”

Chertoff has dismissed objections raised about these devices. “The ‘safety’ concern,” he claimed In a Washington Post op-ed, “is particularly specious, because the technologies expose people to no more radiation than is experienced in daily life.”

Not quite. Whole body X-ray scanning machines were developed and first used to detect theft at gold and diamond mines on and inside the bodies of workers in Africa. They are fluoroscopic X-ray machines that provide a real-time image of a person’s body using “back-scatter,” or “soft” X-rays. They emit much less penetrating energy than machines found in a medical setting, such as CT scanners. However, like all machines, if their design, manufacture, calibration or maintenance is defective, then doses to passengers and security staff could be larger than claimed. The recent reporting of dozens of cases of harm to patients from the misuse of CT scans should serve as a cautionary warning.

Unfortunately, the doses of radiation experienced in everyday life, especially flying long distances in jet aircraft, pose risks we should also carefully heed.

Flight crews are considered by the United Nation’s Scientific Committee on the Effects of Atomic Radiation as radiation workers who, because of exposure to cosmic radiation, are the most highly exposed group in the world. For instance:

• According to UN data, in 2000, air crews made up about 3 percent of the radiation workers in the world, but received about 24 percent of the total collective dose for all exposed workers, which include people employed at uranium mines, nuclear weapons sites, and nuclear power plants. The average estimated annual dose to flight personnel, and frequent international flyers such as professional couriers, is about 2.5 times higher than the combined average for all radiation workers.
• Aircrew and frequent long-distance passengers are chronically exposed to more biologically damaging forms of radiation, such as neutrons, than the majority of nuclear workers.
• Pregnant women have a heightened risk of cancer to their embryos. During the early part of the first trimester, when radiation sensitivity is the highest, some women may not know they are pregnant. This is why European airlines ground pregnant aircrew to prevent overexposure.
• Over the past decade, at least 11 studies of civilian and military airline crews show significant increased risks of dying from cancers considered to be radiogenic. The aircraft environment includes other potential and multiple risk factors that aren’t as well understood as radiation, such as electromagnetic fields, changes in body hormones, time-zone changes, pesticides, pressure changes, chronic fatigue, and lifestyles. The aircraft environment includes other

Given the dire economic problems airlines face, this problem is the last thing that they want to surface. But if crew members and passengers already face largely unreported radiation risks from long-distance flying, we should have the right to know just how whole-body radiation scanning machines are part of this risk.