For related articles and more information, please visit OCA’s Health Issues page.

Holiday flyers take note: The federal Transportation Security Administration (TSA) has been quietly removing its admittedly cancer-causing full-body X-ray scanners known as “backscatter” machines from seven large US airports. About 280 are still in use at about 40 airports.

Public opposition and criticism from health scientists, the ACLU and Congress have pressured the TSA to either get rid of the machines or make them less invasive. The X-ray systems are being replaced with “millimeter-wave” technology – machines that use radio waves similar to cell phones – at Los Angeles International, Chicago O’Hare, Orlando, Logan International in Boston, and Kennedy and LaGuardia in New York City.

Jay Stanley with the American Civil Liberties Union told the Associated Press that the scanners “continue to be surrounded by health questions.” The ACLU’s gripe with the machines is that the X-ray images of passengers’ naked bodies are an invasive assault on privacy. The millimeter wave machines produce a stock image with software that alerts the TSA to any potential weapons or explosives.

Other critics raised health questions, especially regarding children, infants, fetuses and pregnant women, all of whom are more vulnerable to radiation than the “”Reference Man” used often to quantify radiation risk. In December 2010, routine maintenance of the machines showed they were emitting more than 10 times the radiation expected. The TSA said then that the results were due to a mathematical error and that all the machines are safe.