Editor’s Note: This week, the Food and Drug Administration sent us a letter, which we have posted below, taking issue with several passages in our story about airport body scanners. The letter generally takes semantic issue with how we presented specific facts. It does not, in our judgment, raise any issues of substance.

For example, a section heading in our story stated that there has been little research on the cancer risks of body scanners. The FDA asserts that studies of radiation risk in general should be accepted as applying to the radiation generated by the scanners.

More broadly, the FDA takes issue with how we conveyed the cancer risk from the scanners. The agency says the amount of radiation the scanners emit is “extremely small.” We call it “extremely low.” The agency says the risk of fatal cancer is 1 in 400 million – an estimate it did not provide to ProPublica before publication – and cites the National Council on Radiation Protection and Measurements (NCRP) to say that estimating cancer cases from low levels of radiation produces “a distorted image of risk.” We cited two peer-reviewed research papers by prominent academics – including one who served on the NCRP panel that examined body scanners – that estimated six or 100 additional cases of cancer over a lifetime could be caused among the 100 million passengers who fly each year. (Those passengers were estimated to take 750 million or one billion flights.) To put this risk in context, we noted that “the same 100 million people would develop 40 million cancers over the course of their lifetimes.”

Separately, the agency asserts that we erred in stating, “The FDA does not review or approve the safety of such products.” But the agency omits our next sentence: “However, manufacturers must provide a brief radiation safety report explaining the dose and notify the agency if any overexposure is discovered.” That sentence is important, because the FDA letter itself states that “a manufacturer of an x-ray security screening product can legally sell a product after they submit the required radiation safety report. Federal law does not include authority for an approval process for the radiation safety of electronic products.”

In another case, the FDA objects to this sentence: “Instead, the FDA decided to go with a voluntary standard set by a trade group largely comprising manufacturers and government agencies that wanted to use the machines.” The agency says that “FDA chose to initiate a balanced consensus standard development process…” But the “consensus standard” is not mandatory. A company could produce a scanner that exceeds it, and the burden would be on the FDA to show the radiation emitted by such a scanner is unreasonable. Also, in explaining the process of how the standards were set, we believe the FDA does not contradict the essence of our reporting: The task of setting the standard was handled by a non-profit group that sets standards for many industries, the American National Standards Institute. ANSI, in turn, relied on what the FDA acknowledges was the “working group which wrote the standard.” As we reported, that working group, which we termed a committee, “was made up of 15 people, including six representatives from manufacturers of X-ray body scanners and five from U.S. Customs and the California prison system. There were few government regulators and no independent scientists.”

ProPublica takes seriously our responsibility to correct mistakes and clarify misstatements. But while the FDA may prefer different terminology, we believe the way we conveyed the facts was accurate.

–Paul Steiger, Editor-in-Chief and CEO

The FDA’s Response

FDA spokesperson Erica V. Jefferson emailed ProPublica the following response for publication.

ProPublica article Nov 1, 2011 – clarifications

For further information and references regarding these topics please visit the FDA web page on products for security screening of people - http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/SecuritySystems/ucm227201.htm

For an overview of FDA’s regulatory authorities over manufactures of electronic products please see the FDA Basics page regarding radiation emitting products: http://www.fda.gov/AboutFDA/Transparency/Basics/ucm193809.htm