2022:16 Recent Research on EMF and Health Risk

Sixteenth report from SSM’s Scientific Council on Electromagnetic Fields, 2021

SSM perspective


The Swedish Radiation Safety Authority’s (SSM) Scientific Council on Electromagnetic Fields monitors current research on potential health risks in relation to exposure to electromagnetic fields and provides the authority with advice on assessing possible health risks. The Council gives guidance when the authority must give an opinion on policy matters when scientific testing is necessary. The council is required to submit a written report each year on the current research and knowledge situation.

This is a consensus report. This means that all members of the Scientific Council agree with the complete report. This increases the strength of the given conclusions.

The report has the primary objective of covering the previous year’s research in the area of electromagnetic fields (EMF) and health but also to place this in the context of present knowledge. The report gives the authority an overview and provides an important basis for risk assessment.


This report reviews studies on electromagnetic fields (EMF) and health risks, published from January 2020 up to and including December 2020. The report is the sixteenth in a series of annual scientific reviews which consecutively discusses and assesses relevant new studies and put these in the context of available information. The report covers different areas of EMF (static, low frequency, intermediate and radio frequency fields) and different types of studies such as biological, human and epidemiological studies. The result will be a gradually developing health risk assessment of exposure to EMF.

No new established causal relationships between EMF exposure and health risk have been identified.

The studies presented in this report do not resolve whether the consistently observed association between ELF magnetic field (ELF-MF) exposure and childhood leukaemia in epidemiology is causal or not.

Only a very limited amount of new research has been published on tumour risk in relation to mobile phone use. Associations between mobile phone use and insomnia-like symptoms have been observed as in previous years. However, insomnia was associated rather to the time period of use than to the level of radiation exposure. This suggests that other factors than RF-EMF (Radiofrequency-EMF) may explain the observed association. Such factors may include for example stress or other behavioural factors. For insomnia-like symptoms, a significant interaction was found in one study between RF-EMF exposure from mobile phone base stations and environmental concerns, which indicates communication needs with the public about potential health risks from mobile phone base station. New studies in adolescent on cognitive functions and brain volume do not indicate a risk from RF-EMF exposure.

Concerning studies on animals, it is difficult to draw general conclusions other than that under certain circumstances some effects from RF-EMF exposure are observed in experimental animals. The observations of increased oxidative stress reported in previous SSM reports continue to be found, some even below current reference levels. Oxidative stress is a natural biological process that can sometimes be involved in pathogenesis, but under what circumstances oxidative stress due to weak radio wave exposure may affect human health remains to be investigated.

Despite the increasing use of applications in the intermediate frequency (IF) range of the electromagnetic spectrum (300 Hz-10 MHz), scientific evaluation of potential health risks in that range is scarce. However, the few studies identified by the council in this area have not indicated any health effects below current reference levels.

The annual report also includes a section where studies that lack satisfactory quality have been listed. This year, as well as last year, many studies have been excluded due to poor quality (see appendix). From a scientific perspective, studies of poor quality are irrelevant. They are also a waste of money, human resources and, in many cases, experimental animals.


The results of the research review give no reason to change any reference levels or recommendations in the field. However, the observations of biological effects in animals due to weak radio wave exposure clearly show the importance of maintaining the Swedish Environmental Code precautionary thinking.

SSM:s hands-free recommendation for mobile phone calls remains even though trends of glioma incidences do not provide support for an increasing risk caused by mobile phone radio wave exposure. However, observed biological effects and uncertainties regarding possible long term effects justify caution.

No new findings that clearly change the suspicion of a causal link between weak low-frequency magnetic fields and childhood leukaemia have emerged in the report. The Swedish authorities’ recommendation to generally limit exposure to low frequency magnetic fields due to the observed increased incidence of childhood leukaemia close to power lines remains unchanged.

Need for further research

Despite the fact that no health risks associated with weak electromagnetic fields have been demonstrated up to date, the authority considers that further research is important, in particular regarding long-term effects as more or less the entire population is exposed. One key issue here is to further investigate the relationship between radio wave exposure and oxidative stress observed in animal studies and to establish whether a relationship in humans exists and, if so, to what extent it may affect human health. Another important issue is to clarify the association between weak low frequency magnetic fields and childhood leukaemia as observed in epidemiological studies.

Since epidemiological studies often report impact on cognitive functions (non-specific symptoms such as headache and mental health problems) due to the use of information technology, it is desirable to further investigate if this association to some extent depends on the resulting radio wave exposure. The authority would like to emphasize that innovative approaches allowing differentiating between device usage and physical radio frequency EMF exposure are needed to better understand the causality of radio frequency EMF exposure for health.

Wireless information technology is constantly evolving and new frequency ranges will be used. The fifth generation mobile telecommunication system (5G) will be installed all over the world within the next few years. Even though there is no established mechanism for affecting health from weak radio wave exposure, there is need for more research covering the novel frequency domains used for 5G. The authority also encourages researchers to start undertaking epidemiological studies, i.e. cohort studies, in this area. There are currently very few studies in the 26 GHz band.

New technologies for inductive wireless energy transfer based on intermediate frequency magnetic fields will probably be implemented for many different applications in the near future. In contrast to wireless information communication technology, wireless energy transfer in principle always results in relatively strong local fields. This makes it very important to obtain a robust basis for risk assessment of such fields. Today, there is a lack of studies in this frequency domain, and therefore, there is a special need for research in this area.

Another vital issue to further investigate is whether exposure to low frequency magnetic fields contribute to the slightly increased incidence of childhood leukaemia that has been observed close to power lines in epidemiological studies. When animal studies are planned regarding this issue, the authority encourage the use of the novel mouse design ETV6- RUNX1 (Campos-Sanchez et al. (2019)).

It is also desirable to investigate different health effects based on combinations of electromagnetic fields and other factors, both physical factors and chemical factors.