BIOLOGICAL EFFECTS OF ELECTROMAGNETIC-FIELDS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 34  (7-8) , 616-627
Abstract
Thermal and nonthermal effects of electromagnetic fields on man are reviewed. Only direct and immediate influences on biological cells and tissues are discussed; the treatment is limited to such phenomena for which biophysical approximations, based on experimental data, could be developed. Hazards for humans may occur only by thermal effects within the microwave range. Regarding frequencies below approximately 30 kHz, excitation processes cannot be excluded in exceptional cases. Thermal effects are predominant between 30 and 100 kHz before excitations can appear. By comparing the electrically and magnetically induced currents with the naturally flowing currents in man caused by brain and heart electrical activity, a lower boundary-line was estimated. Regarding electric or magnetic field strengths undercutting this boundary-line, direct effects on the CNS may be excluded; other mechanisms should be responsible for demonstrated biological effects. Some reports on experimental findings of biological effects, which were observed as a result of the influence of electromagnetic fields of small field strengths, are mentioned.