# Assessment and Categorization of Biological Effects and
## 3 RF-EMF Exposure
### AS Due to RF-EMF  
As stated earlier, EMF exposure has two categories of effects on human health. The first is related to short-term exposure to EMF, and the second is result of long-term exposure. Short-term effects are those relative to usual thermal effects as well as that result in AS for EHS people showing non-specific symptoms mentioned earlier. Long-term ones are those related to non-thermal effects as well as AS long-term effects on CF. As mentioned previously, in rare cases people present AS owing to exposure to RF-EMF. Among these persons are subjects with EHS that present with non-specific symptoms. These range widely between people and include headaches, weakness, anxiety, trouble sleeping, skin tingling, burning sensations, muscle problems with agony and pain and other different symptoms. Historically, this phenomenon appeared a few decades ago and in particular with the advent of modern digital communication technologies [21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32]. Figure 2: Input EMF exposure (parameters, nature and condition) and output effects on tissue. These non-specific symptoms were presented for a wide range of frequencies and different types of sources, but the vast majority involved RF sources. Even those EMF in the RF range act to the greatest danger to humans if the field strength and SAR are relatively high; EHS symptoms can be present for non-significant values of these measures. For example, the SAR activated in such sources could reach in certain uses about ten W/kg depending on the intensity of the field and its frequency. For a short time, this is enough to cause a temperature rise of 1 \({}^{\circ}\)C in body tissues, which in a normal healthy case is completely safe. At the same time, for SARs less than 0.1 W/kg, symptoms may be present in an EHS subject. This negligible level of exposure seems surprising given the many radiating RF-EMF tools in the everyday environment. Indeed, EHS subjects often fall into the category of users nearby and relatively far from the tools for which the field decreases as the square of the distance. In addition, these tools are generally subject to electromagnetic compatibility rules and adapted to avoid BE in the body tissues of users [1; 2; 3]. The EHS symptoms seem real and their presence is associated with EMF even if the biological effect of the latter seems non-existent. Most investigations only consider EMF-induced BE that are acknowledged by the scientific medical organization. In fact, health agencies are gradually admitting RF EHS. Subjects enduring EHS expose symptoms in cases of field insignificant enough not to create perceptible BE. The term hypersensitivity (HS) may introduce a misinterpretation and one may use idiopathic environmental intolerance (IEI), which signify better the state of sickness. Thus, it can be used in case of EM, EHS or EIEI. According to patients and often verified by double blind (patient and supervisor) experiences, these symptoms appear only occasionally at first, but then they become more prominent and more persistent. Even with such an insignificant level of exposure, one can think that electromagnetic effects ignored today may perhaps emerge below the established exposure intensities and elucidate the EHS symptoms. Decidedly, it is scientifically difficult to refute the presence of a danger. Such uncertainty can constantly justify a cautious attitude [33]. As in the case of subjects with EHS, we have another similar case of AS relative to the same type of exposure but for longer duration. This is the case of long-term effects of exposure to RF-EMF on CF. As in the case of EHS, this problem appeared with the advent of modern digital communication technologies and in particular the use of mobile cell phones. The RF-EMF exposure from these devices affects directly the brain tissues and consequently the cognitive function that involve diverse cerebral abilities.