This reference explores the sources, characteristics, bioeffects, and health hazards of extremely low-frequency (ELF) fields and radio frequency radiation (RFR), analyzing current research as well as the latest epidemiological studies to assess potential risks associated with exposure and to develop effective safety guidelines. It discusses EM interaction mechanisms in biological systems, the impact of EM fields on free radicals, cells, tissues, organs, whole organisms, and the population, regulatory standards in the United States, Canada, Europe, and Asia Pacific, evaluation of incident fields from various EM sources, and dosimetry techniques for the determination of internal EM fields.