Abstract
Mobile telecommunication and internet technologies have been rapidly developed during last two decades. Concomitantly, the number of people is growing, who suffer from electromagnetic hypersensitivity (EHS). Hence, a causal relation between the electromagnetic waves and EHS has been suspected. International Commission on Non-Ionizing Radiation Protection (CNIRP) set a limit of the exposure to electromagnetic waves. However, the limit is based on the physiological limit that has been derived from the physically accepted interaction of the electromagnetic waves and the human body. Thus, the limit is three orders of magnitude higher than the level above which the patients of EHS normally develop their symptoms. The prevailing view is that humans do not feel magnetic fields that are lower than the above limit. Hence, the principle of the setting of the limit has not been questioned. However, some species such as bacteria, birds, reptiles and fishes seem to possess geomagnetic sense and utilize it for navigation. In this commentary, I will first explain how the limiting values for the electromagnetic waves have been determined and then briefly explain geomagnetic sense of bacteria and that of homing pigeons. It turned out that these sensing mechanisms cannot detect the magnetic field that has been attributed to the cause of EHS. Thus, I will explain a recently proposed hypothesis based on the interaction between radicals and the local magnetic fields (= geomagnetic field + time-varying magnetic field originated from the electromagnetic wave). It has been hypothesized that the precession of the radical in the local magnetic field is highly sensitive to the presence of the time-varying component in the local magnetic field, and even the time-varying magnetic field of less than 1 microtesla can modulate the chemical reaction that involves the radical.
