enough to strip molecules in the body of their electrons, creating charged particles that cause cell damage and are thought to be the mechanism through which radiation causes cancer." Humans are exposed to background radiation every day, anywhere on earth, and proponents of backscatter X-ray scanners say that the devices expose subjects to levels of radiation equivalent to background radiation. Furthermore, when traveling on an airplane, passengers are exposed to much higher levels of radiation than on earth due to altitude. Proponents say that a backscatter X-ray scan is equivalent to the radiation received during two minutes of flying. The UK Health Protection Agency has also issued a statement that the radiation dose from backscatter scanners is very low and "about the same as one hour of background radiation". The European Commission issued a report stating that backscatter X-ray scanners pose no known health risk, but suggested that backscatter X-ray scanners, which expose people to ionizing radiation, should not be used when millimeter-wave scanners that "have less effects on the human body" are available. Assuming all other conditions equal, there is no reason to adopt X‐ray backscatters, which expose the subject to an additional – although negligible – source of ionizing radiations. Other WBI (Whole Body Imaging) technologies should be preferred for standard use. However, the European Commission's report provides no data substantiating the claim that "all other conditions are equal". One area where backscatter X-ray scanners can provide better performance than millimeter wave scanners, for example, is in the inspection of the shoes, groin and armpit regions of the body. The European Commission also recommended that alternate screening methods should be "used on pregnant women, babies, children and people with disabilities". In the United States, Senator Susan Collins, Ranking Member of the Senate Homeland Security Committee sent a letter on August 6, 2010, to the Secretary of Homeland Security and Administrator of the TSA, requesting that the TSA "have the Department's Chief Medical Officer, working with independent experts, conduct a review of the health effects of their use for travelers, TSA employees, and airport and airline personnel." The TSA has completed this review. The U.S. government is also supplying higher-radiation through-body X-ray machines to at least two African countries "for the purposes of airport security – the kind that can see through flesh, and which deliver real doses of radiation. The U.S.-supplied scanners have apparently been deployed at one