ABSTRACT
This chapter presents a brief review of the electromagnetic theory that applies to understanding the effects of electromagnetic fields on biological systems. Starting from the basic equations for DC, low- and high-frequency fields, it goes on to define and give relationships for near fields and radiation fields of high-frequency radiation. The way physical conditions affect penetration of direct current and low-frequency electric fields, magnetic fields, and RF fields in tissue is discussed, followed by similar discussions for direct current and low-frequency magnetic fields and for RF fields. Finally, there is a discussion of certain biophysical factors affecting interactions of fields: ionization, ionizing radiation, chemical bonds, and excitation.
