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The new “strip search” scanning machines at airport security checkpoints are increasingly causing furor over issues of privacy, decency and health. Over the weekend, a passenger in San Diego, software engineer John Tyner, opted out of a scan, then warned a security agent not to “touch my junk” during the enhanced pat-down check — that interaction, which Tyner recorded on his cell phone and posted online, went viral, further stoking the public’s frustration.

Whether or not you feel the new backscatter body scans (let alone the security gropes) are an overly humiliating invasion of privacy, there’s no arguing that the scans expose you to extra radiation. Many passengers and some scientists say the excess radiation exposure could pose a health hazard to frequent fliers and to young children. (More on Time.com: 6 Common Sources of Radiation In Your Life)

For its part, the Allied Pilots Association, the pilot’s union, publicly advised its members — who are scanned two to three times per day during the course of their work — to opt for private pat-downs instead of the scan, noting that “airline pilots in the United States already receive higher doses of radiation in their on-the-job environment than nearly every other category of worker in the United States, including nuclear power plant employees.”

The Transportation Security Administration (TSA) and Department of Homeland Security maintain that the scanners emit safe levels of radiation, which DHS director Janet Napolitano called the “equivalent of about two minutes of flying” during a press conference.

But the scans may be exposing passengers to more radiation than Napolitano is letting on. Healthland’s Alice Park wrote in October that many scientists doubt the accuracy of the scan manufacturer’s and government’s calculation of low exposure: