Power frequency electromagnetic fields (EMF) are generated in the production, transport, distribution and use of electricity. The frequency of alternating current and the resulting EMF is 50 hertz in Africa, most of Asia, Australia, Europe and part of South America and 60 hertz in the remainder of America, the Philippines, Korea, Saudi-Arabia and part of Japan. Radiofrequency EMF are generated, among others, by mobile telecommunication systems, broadcasting transmitters, radar installations, microwave ovens, certain medical applications and equipment for electronic article surveillance and identification.