In a letter sent to White House, a group of scientists are questioning tests that the TSA is using to claim that full body scanners used at airports are safe. The letter was a response to a letter from the Department of Health and Human Services regarding a letter sent last year by the scientists
The five scientists who signed the letter question why the TSA won't make the scanners available for independent testing by outside scientists.
The professors, from the University of California, San Francisco, and one at Arizona State University, point out several flaws in the tests.
They note that the Johns Hopkins lab, where the tests were conducted, didn't test an actual airport machine. Instead, the tests were done on a model built by the manufacturer, Rapiscan, and configured to resemble a system previously tested by the TSA.
The Johns Hopkins researchers' names have been kept secret, and the report on the tests is so "heavily redacted" that "there is no way to repeat any of these measurements," the scientists wrote.
The scientists also raised concerns about the device used to measure the radiation. Although the device, known as an ion chamber, is commonly used to test medical equipment, they argue that the detector gets overwhelmed by the amount of radiation the backscatter deposits in a short time and might not provide accurate readings.