The possibility of previously unrecognised adverse health effects of electro-magnetic (EMF) from high-voltage electric power lines have been discussed since the 1970s. The concern was triggered primarily by epidemiological studies in the United States and Europe that suggested a slightly increased incidence of leukaemia's and brain tumours occurred among those living near power-lines and among utility employees working near high-voltage power lines. However, although epidemiological studies can indicate and association between a factor and effects, epidemiological studies by themselves cannot confirm a cause-effect relationship. Whether EMF is causing the effects must be confirmed by experimental studies. We believe this book also will be of significant value for helping society to understand what is known about the concern that exposure to power-frequency EMF might have adverse public health effects. The editors of this book believe that the research reported in this book should be widely circulated to the international scientific community, believing that the work is both comprehensive and conducted according to the highest scientific standards.