RF EMFs
100 kHz - 300 GHz
Listen to Eric van Rongen, the current ICNIRP Vice Chair.
In this presentation the 2020 RF Guidelines are referred to as ICNIRP 2019.
Frequency range and use
“Radiofrequency Electromagnetic Fields” (RF EMFs) is the term used to describe the part of the electromagnetic spectrum comprising the frequency range from 100 kHz to 300 GHz. Within this frequency range, the electric and the magnetic fields, which together make up the electromagnetic fields, are interrelated and considered jointly for measurements. RF EMF exposure is usually measured in watts per square meter (W/m2) or watts per kg (W/kg).
RF EMF fields are used in a variety of technologies, most widely for communication purposes (e.g. mobile phones, base stations, Wi-Fi, 5G, radio, TV, security devices), and also in medicine (e.g. Magnetic Resonance Imaging (MRI) equipment), for heating purposes (e.g. microwave ovens) and for wireless power transfer (e.g. Qi).
RF EMF effects on the body and health implications
After several decades of RF-EMF research on numerous potential health effects, the only substantiated effect of RF EMF exposure relevant to human health and safety is heating of exposed tissue. RF EMF fields can penetrate into the body (the higher the frequency, the lower the penetration depth) and cause vibration of charged or polar molecules inside. This results in friction and thus heat.
The body can accommodate a small increase in heat, in a similar way that excess body heat is dissipated when performing sporting activity. This is because the human body has a strong ability to regulate its internal temperature. However, above a certain level (referred to as the threshold) depending on the duration of exposure, RF EMF exposure and the accompanying temperature rise can provoke serious health effects, such as heatstroke and tissue damage (burns).
Acute and long-term effects of RF EMF exposure below the thermal threshold have been studied extensively without demonstrating adverse health effects.
A considerable amount of research has been conducted on the relationship between RF EMFs and health outcomes such as headaches, concentration difficulty, sleep quality, cognitive function, cardiovascular effects, etc. This research has not shown any such health effects. The only consistently observed finding is a small effect on brain activity measured by electroencephalography (EEG). The biological implication of these small changes is, however, unclear. For example, they have not been shown to affect sleep quality or be associated with any other adverse effects.
Extensive research has been undertaken in relation to exposure to RF EMFs used specifically in mobile telephony, and cancer. Among all of this research, the risk of tumours in close proximity to the ear where the phone is held, e.g. brain tumours, has been the focus of the majority of epidemiological studies. A few of these epidemiological studies have reported a slight statistical increase in risk of some brain tumours for the small group of long-term and heavy mobile phone users (read more). Reporting biases and weaknesses of the studies may explain the observed findings. Several studies have not reported any increase in brain tumours with mobile phone use. Also, experimental studies on animals and cells have failed to confirm the findings of the epidemiological studies, and there is no biophysical mechanism that could explain carcinogenicity at such low exposure levels. In addition, the increased risk observed in some of the epidemiological studies is inconsistent with the stable frequency of occurrence of these cancers in the population. That is an important consideration, given the widespread and significant increase in the use of mobile phones in the general population during the last few decades.
The overall evaluation of all the research on RF EMFs leads to the conclusion that RF EMF exposure below the thermal threshold is unlikely to be associated with adverse health effects.
Protection
To avoid hazards to health and prevent adverse interaction with RF EMFs (i.e. to prevent whole-body heat stress and excessive localized heating), ICNIRP recommends limiting the exposure to RF EMFs so that the threshold at which these interactions become detrimental is never reached. The exposure limits, called basic restrictions, are set in relation to the thresholds known to show adverse effects, with additional conservative factors incorporated to take care of scientific uncertainties pertaining to the determination of the threshold. The basic restrictions are generally expressed in terms of the specific energy absorption rate (SAR), or the absorbed power density. Distinct basic restriction values are recommended for different parts of the body and for sources operated close to the body and those operating at a remote distance. Exposure levels outside the body are called reference levels. These are derived from the basic restrictions using worst-case realistic assumptions, in such a way that remaining below the reference levels (in air) will result in exposures (in the body) that are substantially lower than those resulting from the basic restrictions in the vast majority of cases.
ICNIRP has published a set of new guidelines in this frequency range. The ICNIRP 2020 RF EMF guidelines protect against all potential adverse health effects relating to exposure to RF EMF, including from 5G technologies. The ICNIRP (2020) guidelines has made a number of improvements to health protection and provides more-detailed guidance for the application of its health protection system. These include the addition of whole body average restrictions for EMF frequencies above 6 GHz, restrictions for brief (< 6 minutes) exposures for EMF frequencies above 400 MHz, and the reduction of the averaging area for EMF frequencies above 6 GHz.