Immunologic and Cancer-Related Aspects of Exposure to Low-Level Microwave and Radiofrequency Fields

Microwave electromagnetic radiation (MW), 300–300,000 MHz (wavelength in air 1 m to 1 mm), and radiofrequency electromagnetic radiation (RF), 0.3–300 MHz (wavelength in air 1,000–1 m), are both relatively new but rapidly intensifying occupational and environmental factors. For about 40 years there has been a steadily increasing exposure of both occupational groups and the general population to various intensities of these radiations due to the use of MW/RFs in radar, navigation, communication, and television, as well as for multiple industrial and household purposes. Thus, biological effects and possible health hazards of MW/RFs have become an important problem to be solved in connection with the elaboration of valid safety standards. Despite numerous experimental studies and epidemiologic observations (1,2), and distinct philosophies of MW/RF safety standards in the U.S. and West European countries versus Eastern European countries, it is still not possible to prove the existence and character of specific molecular, cellular or system-related damages that may be evoked by exposure to low-level MW/RF fields. Most of the observed effects are inconsistent, transient and difficult to confirm and interpret. Absorption of a certain amount of electromagnetic energy in cells, biological tissues, and in living organisms results in a thermal load that cannot be dissipated to the environment. After exceeding the capacity of the thermoregulatory and adaptation mechanisms, it leads to an increase of temperature with all the known consequences of local or whole-body hyperthermia. Physiologic and pathologic effects of short-lasting MW hyperthermia have often been misinterpreted as being directly due to the influence of the radiation, and only recently, after progress in the measurement of specific absorption rates (SARs), the two phenomena have been differentiated.