Human sleep is characterized by different stages that occur in several cycles at night and which can be measured e.g. in the EEG. In sleep studies it has to be distinguished between physiological data (i.e. EEG) and subjective reports on sleep quality (e.g. questionnaires), which can both be used to analyze sleep. The assessments which have been derived from each of these methods can deviate substantially (SCENIHR, 2015, p.104).
Some people who complain about sleep disorders associate them with electromagnetic fields. In a study of 2007 on that topic authored by Prof. Norbert Leitgeb (Leitgeb, 2007, p.3) and published by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) it is stated, that, in the past decades, the occurence of sleep disorders has significantly increased. More than 20% of the population report occasional sleep disturbances, e.g. disturbances in the onset of sleep, sleep quality, sleep patterns or sleep profile. According to Leitgeb, an increasing part of these people attribute these disturbances to the influences of radiofrequency electromagnetic fields emitted from transmitters, especially from mobile phone base stations. These assumptions had reached a political dimension and had led to petitions and appeals for the reduction of exposure limit values and a constraint of mobile communication, especially at the end of the 90s and at the beginning of the 2000s (in German only; Freiburg Appeal 2002, Cellular Radio Petition 1999, Cellular Radio Petition 2003, Resolution to Minimize the General Electromagnetic Pollution 1999) (Leitgeb, 2007, p.3).
The effects of mobile communication related radiofrequency electromagnetic fields on sleep have been investigated in a multitude of studies. An overview of all experimental studies on sleep and epidemiological studies on sleep can be found in the study overview on mobile phones in the EMF-Portal. The different international and national committees which have evaluated the existing data are not consistent with regard to the evidence of the effects in the sleep EEG. However, they agree in terms of possible consequences for health.
At international level, the World Health Organization (WHO) saw no consistent evidence of adverse health effects from radiofrequency electromagnetic fields in view of studies on sleep in its last short statement (Fact sheet № 193, 2014). The International Commission on non-ionizing radiation protection (ICNIRP) agrees with this opinion, though it mentions that GSM signals may have a weak effect on the sleep EEG (some studies described an increase of the alpha wave band and beta wave band activity) (ICNIRP, 2009, p.257).
At European level, the Scientific Committee on Emerging and Newly Identified Health Risks of the EU (SCENIHR, 2015, p.126 f) sees some evidence for small effects on the sleep EEG as well. The observed effects are deemed as inconsistent, but they seem to depend on the type of signal (type of exposure, duration, pulse modulation) and affect different EEG bands during different sleep stages. SCENIHR contradicts other experts (e.g. the Swedish Radiation Safety Authority (SSM), 2013, p.9) who claim that effects on sleep EEG are consistent.
With reference to the German Mobile Telecommunication Research Programme (DMF), the German Commission on Radiological Protection (SSK, 2011, p.24 f) cannot confirm any effects of mobile communication fields on the sleep EEG or the sleep quality. However, it notes that concern over detrimental effects alone can cause sleep disorders. The SSK sees a need for further research, especially on the investigation of possible age-related effects.
On the contrary, the Federal Office for the Environment (FOEN, 2014, p.22 f) in Switzerland sees sufficient evidence for an increased activity in the EEG frequency band from 12-15 Hz during sleep through mobile communication exposure. However, it is pointed out that the effects on the EEG activity are small and do not affect sleep quality. The FOEN sees possible reasons for the inconsistency of study results in the strong individual differences in the EEG reactions as well as in the variable effects of different types of signals and modulation-specific effects. Hence, it demands further research.
Further information on the effects on EEG (including sleep EEG) can be found in chapter „EEG/brain activity“.
To summarize, it can be concluded, that international and national expert committees consider that small effects from mobile communication related radiofrequency electromagnetic fields on the sleep EEG are possible. However, there is not sufficient evidence for effects on sleep quality and relevant health effects. A new and detailed opinion from the WHO regarding effects of radiofrequency electromagnetic fields is expected in 2016 (Fact sheet № 193, 2014).