# Assessment and Categorization of Biological Effects and
## 1 Introduction  
The interaction of electromagnetic fields (EMF) with living tissues or manufactured objects can produce different effects on these exposed entities. In different circumstances, these fields are used daily in various friendly applications. Moreover, they are utilized safely in healthcare, either directly on the human body or in the operation of medical instruments. However, when exposure to these fields occurs incidentally or accidentally, it can produce adverse effects. Thus, the increase in the daily use of EMF has prompted studies concerning their effects in various domains and in particular that of public health. This inquest was devoted to the effects of electromagnetic (EM) exposures at the frequency and power of the emitting source on the various tissues of the human body to assess the potential effects in accordance with international health-safety standards [1; 2; 3]. These effects are closely related to the nature of the EMF and the exposed matter. The intensity of the field and its frequency characterize EMF, while the biological and geometric properties of the different parts and tissues of the body characterize matter. Devices emitting EMF used daily mainly expend frequencies producing non-ionizing radiation. However, in specific healthcare procedures, the frequencies may be in the range of ionizing radiation; in this case, exposure is restricted and controlled. In fact, the consequences due to exposure to EMF can be separated into two distinct categories concerning the frequency ranges, and the corresponding wavelengths. The first concerns the range of \(10^{3}\)-\(10^{14}\) Hz where EM waves can be split into radio, microwaves and infrared that produce non-ionizing radiation. The second regards the range of \(10^{15}\)-\(10^{22}\) Hz divided into ultraviolet, X and gamma rays, which generate ionizing radiation. In the caseof ionization, the radiated energy is high enough to cause the release of electrons, which are expelled from the atoms; the consequence is the materialization of pairs of ions, which are ionization. This is likely to have adverse health effects by generating molecular disturbances leading to tissue damage. On the contrary, the non-ionizing case is distinguished by the fact that the radiated energy is too weak to cause the release of electrons from their orbits in the atoms. Thus, non-ionizing radiation signifies that its conforming excitation energy level infers that electrons even with a changed energy state remain in their atoms avoiding the creation of charged ions. EMF of different frequencies, in the range of non-ionizing category, operate in several circumstances and can disrupt human society. The research followed in this contribution falls into this category of frequency range. In general, the apparatuses most involved in EMF non-ionizing exposure are those exerting significant stray fields such as wireless energy devices embracing wide power and frequency ranges. A typical class is the case of digital communications comprising ordinary sources of radiofrequency (RF), \(10^{5}\)-\(3\times 10^{11}\) Hz, emissions by, e.g., antennas, Wi-Fi points, smartphones, Bluetooth tools. In this case, moderate field strength but relatively high frequencies RF characterize the exposure of the human body to emissions from these devices. Such RF-EMF implies rigorous control of the safety conditions; see for example [4; 5; 6; 7; 8; 9]. Humans exposed to RF-EMF endure biological effects (BE) which, with common use of RF tools, are primarily thermal due to energy dissipation. These BE must not exceed the limits set by the safety standards. By respecting these standards, the exposed subjects do not normally risk any inconvenience. These thermal BE due RF-EMF exposure are the most common with usual use of digital communication devices. Moreover, there are also lesser frequently effects that are non-thermal. In addition, other special cases relate to rarer people who show dissimilar effects due to such exposure. These will present with atypical symptoms (AS).