2024 年 62 巻 2-3 号 p. 77-87
Electromagnetic waves below 3000THz (1THz=1012Hz) are called “non-ionizing radiation,” while those below 300GHz are commonly referred to as “radiofrequency (RF) waves” (but are defined by the Radio Law of Japan as electromagnetic waves with frequency spectra from 10kHz to 3000GHz) . The primary effect of RF waves on human physiology is acute, resulting from the heat-generating effect of induced currents within the body. The magnitude of this effect correlates with the RF wave strength when the biological threshold is exceeded, but there is no cumulative effect for exposure to radio waves below the threshold. This concept is analogous to the acute effects (non-probabilistic effects) of ionizing radiation, based on the hypothesis that weak radio waves do not cause late effects (probabilistic effects) in humans. This review paper provides an overview of the bioeffects of electromagnetic waves on humans from an electrical engineering perspective, followed by a comparison of Japan’s guidelines with international safety standards for human protection from radio waves, focusing on the heat-generating effects of RF waves, along with the underlying principle and rationale behind safety limits and protection guidelines for whole-body exposure to radio waves.