This book addresses new technologies being considered by the Federal Aviation Administration (FAA) for screening airport passengers for concealed weapons and explosives. The FAA is supporting the development of promising new technologies that can reveal the presence not only of metal-based weapons as with current screening technologies, but also detect plastic explosives and other non-metallic threat materials and objects, and is concerned that these new technologies may not be appropriate for use in airports for other than technical reasons. This book presents discussion of the health, legal, and public acceptance issues that are likely to be raised regarding implementation of improvements in the current electromagnetic screening technologies, implementation of screening systems that detect traces of explosive materials on passengers, and implementation of systems that generate images of passengers beneath their clothes for analysis by human screeners.