Shielding and enclosures may also be used to control exposures. These applications include heating in diathermy, cancer therapy, thawing of frozen organs for transplantations, sterilization of ampuls, and enzyme inactivation in tissues of experimental animals. Microwave ovens are also used to heat food. As a result of this heating, potentially damaging alterations may be produced in cells. Some concern also exists for nonthermal effects.
Thermal effects are in direct proportion to the field strength or power density.
When the amount of heat generated from the absorbed energy is too great to be released into the surrounding environment, the temperature of the body gradually increases and can lead to heat stress. The reports of human effects consist of a series of clinical and epidemiologic investigations into the association between RF radiation and damage to the eyes, central nervous system, and reproductive capability. Firm associations between RF radiation and these effects have not been demonstrated. A complete discussion of this literature is beyond the scope of this document. 5.2.4.4.4 environmental monitoring Leakage from diathermy equipment should be monitored in the proximity of the applicator before each treatment.