A diabetic 16-year-old Colorado girl was emotionally traumatized and her health put at risk by a TSA security check after a full body scanner at Salt Lake City Airport apparently incapacitated her insulin pump, according to a report by a local television station. It's only the latest concern about the scanners, which many consumer advocates consider an intrusive, ineffective, and possibly dangerous form of airport security.

There are now some 700 such machines in use at 180 U.S. airports, according to the TSA. A 2011 report by ProPublica and the PBS NewsHour raised questions about a possible link to cancer. Some scanner models, according to testing by the German government, have mistaken perspiration for dangerous chemicals, casting doubt on their reliability. And many travelers have complained that the scanners invade passengers' privacy by taking "nude" photos of them, although the TSA has since implemented softwarethat eliminates anatomical details from the images. Now the Salt Lake City incident raises the newest fear: Can these "advanced imaging technology" scanners, specifically millimeter wave scanners, be harmful to diabetics wearing insulin pumps?

A report last night from Salt Lake City television station ABC4 recounts the experience of Savannah Barry, a Colorado teenager, at a security checkpoint at Salt Lake City Airport. The teen, returning home from a DECA youth leadership conference, advised a TSA agent that she was wearing an insulin pump. She also produced a letter from her doctor that said the pump could be damaged if it were subjected to advanced imaging technology. The TSA agents instructed the 16-year-old to walk through the scanner anyway, at which point the insulin pump stopped working. Then the TSA gave the girl a full-body pat-down, according to ABC4, because she was carrying extra insulin and juice to maintain her blood sugar level, and the machines are not able to scan liquids for safety. According to MSNBC, the TSA said on Tuesday it was attempting to follow-up directly with the young woman and her family and had no further comment.

Advanced imaging technology scanners are not widely used outside the United States. Passengers flying from other countries to U.S. airports aren't necessarily subject to body scanners; that decision is up to each country. The recent discovery of an enhanced "underwear bomb" developed by Al Qaeda, while it never endangered air travelers, raises the question of whether it would have been detected by a full body scanner. Homeland Security Committee Chairman Rep. Peter King, a New York Republican, told CNN: "Every time we think we have them, they come up with something new."

Smart Traveler Mark Orwoll is the International Editor of Travel + Leisure. Follow him on Twitter.