Frequencies in the Electromagnetic Spectrum are expressed in cycles per second, or Hertz (Hz). The higher the frequency, the shorter the distance between one wave and the next, and the greater the amount of energy in the field.
Electric power, in the extremely-low-frequency range toward the bottom of the diagram, is generated and delivered at 60 Hz in North America and 50 Hz in most other parts of the world.
Power frequency fields have wavelengths of more than 3,100 miles (5,000 km) and consequently have very low energy levels that do not cause heating or ionization, though they do create weak electric currents in conducting objects, including people and animals.
In comparison, microwave frequency fields, with wavelengths of several inches, have enough energy to cause heating in conducting material.
Still higher frequencies, such as X-rays, cause ionization—the breaking of molecular bonds—which damages genetic material.
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