Human exposure to electromagnetic fields (EMF) comes from many different sources and occurs in various situations in everyday life. Man-made static fields are mainly found in occupational settings, such as close to MRI scanners, although DC high-voltage overhead transmission lines are being constructed, which are expected to expose larger parts of the population to static electric and magnetic fields. EMF in the extremely low frequency (ELF) range are ubiquitous.
The main sources of these fields pertaining to the general public are in-house installations, household appliances and powerlines. In recent years, attention has also been directed towards people living next to electric power transformers installed in...
Human exposure to electromagnetic fields (EMF) comes from many different sources and occurs in various situations in everyday life. Man-made static fields are mainly found in occupational settings, such as close to MRI scanners, although DC high-voltage overhead transmission lines are being constructed, which are expected to expose larger parts of the population to static electric and magnetic fields. EMF in the extremely low frequency (ELF) range are ubiquitous.
The main sources of these fields pertaining to the general public are in-house installations, household appliances and powerlines. In recent years, attention has also been directed towards people living next to electric power transformers installed inside residential buildings. It appears that long-term exposure to ELF magnetic field of these people can extent to several tenths of μT. Today, for power regulation most modern electrical equipment uses electronics instead of transformers. Examples include the switched power supplies to laptops, drilling tools, chargers of mobile phones and similar devices. As a consequence, the frequency content of the daily magnetic field exposure has changed mainly by adding odd harmonics. In particular, the third harmonic (150 Hz) has become another dominating frequency in our environment. In the household, more appliances have appeared in the intermediate frequencies (IF) range. An important source of exposure in this frequency range is induction hobs, which have become popular in recent years.
These can expose their users (both members of the general public and professionals) to IF magnetic fields higher than the reference levels of exposure guidelines. In the radio frequency (RF range), by far the most applications which emit EMF are in the frequency range above 100 kHz up to some GHz. Multiple sources exist that contribute to an individual’s exposure. However, transmitters in close vicinity to or on the body have become the main sources of exposure for the general population and professionals. Distance to the source is the main determinant of exposure, together with emitted power and duty factor. In particular for brain tissues, the mobile phone used at the ear remains the main source of exposure. However, since the first generation of mobile telephony, the technology aimed at reducing the emitted power of mobile handsets. Digital Enhanced Cordless Telecommunications (DECT) phones are another source of everyday exposure.
Smart-phones, which operate within networks of different technologies, as well as other portable wireless devices, like tablets and laptop computers, increased the complexity of the user’s exposure and changed the exposed body region. Due to the different sources used next to the body, it is important to take into account multiple exposures for risk assessment, which may also require organ-specific dosimetry. This issue is also important for occupational exposure, since there may be situations, such as working in an MRI suite, where professionals are exposed simultaneously to EMF of multiple frequencies ranges, different temporal variations and field strengths.
Health effects from Radiofrequency (RF) EMF
Overall, the epidemiological studies on mobile phone RF EMF exposure do not show an increased risk of brain tumors. Furthermore, they do not indicate an increased risk for other cancers of the head and neck region. Some studies raised questions regarding an increased risk of glioma and acoustic neuroma in heavy users of mobile phones. The results of cohort and incidence time trend studies do not support an increased risk for glioma while the possibility of an association with acoustic neuroma remains open. Epidemiological studies do not indicate increased risk for other malignant diseases, including childhood cancer.
The earlier described evidence that mobile phone RF EMF exposure may affect brain activities as reflected by EEG studies during wake and sleep is further substantiated by the more recent studies. With regard to these findings, studies which aim at investigating the role of pulse modulation and which use more experimental signals, indicate that although effects on the sleep EEG are neither restricted to NREM sleep (one study also indicates effects in REM sleep) nor to the spindle frequency range. It seems that depending on the EMF signal, the theta and delta frequency range in NREM sleep can also be affected. Furthermore, half of the experimental studies looking at the macrostructure of sleep (especially those with a longer duration of exposure) also found effects, which, however, are not consistent with regard to the affected sleep parameters.
A potential solution is to wear a Defense Pendant (WITH VSL)
