Bioelectromagnetics - Thermal Effects

Thermal Effects

Most of the molecules in the human body interact weakly with electromagnetic fields in the radiofrequency or extremely low frequency bands. One such interaction is absorption of energy from the fields, which can cause tissue to heat up; more intense fields will produce greater heating. This can lead to biological effects ranging from muscle relaxation (as produced by a diathermy device) to burns.Many nations and regulatory bodies like the International Commission on Non-Ionizing Radiation Protection have established safety guidelines to limit EMF exposure to a non-thermal level. This can be defined as either heating only to the point where the excess heat can be dissipated, or as a fixed increase in temperature not detectable with current instruments like 0.1°C. However, biological effects have been shown to be present for these non-thermal exposures; Various mechanisms have been proposed to explain these, and there may be several mechanisms underlying the differing phenomena observed. Biological effects of weak electromagnetic fields are the subject of study in magnetobiology.