Written at the request of the U.S. Air Force and Congress, this book evaluates the potential health effects associated with deployment of the Ground Wave Emergency Network (GWEN), a communications system to be used in case of a high-altitude detonation of a nuclear device. The committee, composed of experts in biophysics, physics, risk assessment, epidemiology, and cancer, examines data from laboratory and epidemiologic studies of effects from electromagnetic fields to determine the likelihood of health effects being caused by the operation of a fully implemented GWEN system.