Travel Maze: How Safe Are Whole-Body Scanners at Airports?
But the underlying issue of whether the machines are safe has gotten short shrift. It should be a particular concern for business travelers; after all, many are frequent flyers who pass through security on a regular basis.
The American College of Radiology, the key trade group for radiology professionals, says there is nothing to worry about. "An airline passenger flying cross-country is exposed to more radiation from the flight than from screening by one of these devices,'' said the college in a January statement. The radiation the group is referring to is the naturally occurring radiation in the Earth's atmosphere.
But the issue may not be as simple as the group makes it out in the press release. There are two types of whole-body scanners. Backscatter technology uses extremely weak X-rays, delivering less than 10 microRem of radiation per scan. Scientific experts seem in agreement that those scans are harmless. James Hevezi, chair of the American College of Radiology's Medical Physics Commission, said a traveler would need to experience 100 backscatter scans per year to reach what is classified as a negligible individual dose. By these measurements, he says, a traveler would require more than 1,000 such scans in a year to reach the effective dose equal to one standard chest X-ray.
The second type of scanner uses millimeter-wave technology. This generates low-level radio waves in the millimeter wave spectrum and has fueled more concern. The National Council on Radiation Protection & Measurements, which agrees with ACRs position on the backscatter technology, has not reached a conclusion on the millimeter-wave technology.
"It's probably safe,'' says Thomas Tenforde, the president of RPM, which operates under a Congressional charter. But Tenforde said more study is needed to be sure, particularly looking at travelers subjected to frequent scans. Tenforde said standards have been established for radio frequency exposures up to 300 gigahertz, but millimeter-wave technology operates just above those spectrums. He said potential bioeffects need to be evaluated.
Hevezi said more information on the RF exposures would be helpful. "We have a little more concern,'' he said than on the backscatter technology. He cited the lack of information available on the spectrum that the millimeter-wave technology operates in. But Hevezi said it's most likely safe.
Tenforde said he expressed his concerns to federal officials of the Food and Drug Administration at a meeting the other day, but was told there was no funding available for any studies. Officials said the Transportation Safety Administration would have to fund any study, he said.
But the TSA says there are no problems. Spokesman Sarah R. Horowitz insists both technologies have proved to be safe. Currently, she said, the machines at the 19 airports use the millimeter-wave technology. Machines on order will use the backscatter technology, she says. The machines are optional for travelers who have concerns, she says, but those travelers might be subjected to pat-downs.
The body-scanning machines may become very popular this year. The TSA has 150 on order and the agency is seeking funding to put in place 450 scanners by the end of the year. The Dutch government announced after the incident on the Amsterdam-to-Detroit flight that all passengers headed to the U.S would be subjected to full-body scans. Other European nations are considering similar move for their airports.
The bottom line is the machines are bound to be at an airport of your choice sooner than you think, safe or not so safe.