Effects of short‐ and long‐term pulsed radiofrequency electromagnetic fields on night sleep and cognitive functions in healthy subjects

Abstract

There has been wide public discussion on whether the electromagnetic fields of mobile telephones and their base stations affect human sleep or cognitive functioning. As there is evidence for learning and memory-consolidating effects of sleep and particularly of REM sleep, disturbance of sleep by radiofrequency electromagnetic fields might also impair cognitive functions. Previously realized sleep studies yielded inconsistent results regarding short-term exposure. Moreover, data are lacking on the effect that short- and long-term exposure might have on sleep as well as on cognitive functions. Therefore, 10 healthy young male subjects were included and nocturnal sleep was recorded during eight consecutive nights. In the second, third, and last night, we investigated polysomnographic night sleep and cognitive functions. After the adaptation and baseline nights, the participants were exposed to a defined radiofrequency electromagnetic field during the following six nights. We analyzed polysomnographic night sleep according to Rechtschaffen and Kales [1968, Manual of Standardized Terminology, Techniques and Scoring System for Sleep of Human Subjects] as well as by power spectra and correlation dimension. Cognitive functions were investigated by an array of neuropsychological tests. Data analysis was done by comparing the baseline night with the first and last exposure night and the first two sleep cycles of the respective nights. We did not find significant effects, either on conventional sleep parameters or on power spectra and correlation dimension, nor were there any significant effects on cognitive functions. With our results, we are unable to reveal either short-term or cumulative long-term effects of radiofrequency electromagnetic fields on night sleep and cognitive functions in healthy young male subjects.

Systematic review and meta-analysis of psychomotor effects of mobile phone electromagnetic fields

“…However, if we consider all studies published between 2005 and 2008, we observe a sharp increase in null results 13 16 17 23 25 27 28 39. This difference may be accounted for by greater attention given to methodology, such as self- and hetero-replication of positive results15 18 19a 20 21 25 36 38 and the application of stricter statistical methods (eg, Bonferroni correction for post hoc multiple comparisons).…”

“…Nevertheless, we suggest that both the wash-out period and the acute medium- and long-term responses to repeated EMF exposure require further investigation. So far, no neurocognitive effect has been found with daily acute repeated exposure (three 15 min exposures each day43) in a medium exposure design (between 7 or 9 for 6 nights)13 or in a long-term schedule (2 h daily exposure over 3 weeks) 9…”

The Effects of Mobile-Phone Electromagnetic Fields on Brain Electrical Activity: A Critical Analysis of the Literature

“…Even though the wavelength of mobile-phone radiation is such that the brain of a normal user is in the near field of the phone's antenna (OSHA, 1990), a long-standing practice has been to use the plane-wave approximation (E 2 /377) Becker, 1982a, 1982b) and express the applied field in terms of a power density. Many investigators eschewed use of a Maxwellian variable, and instead listed only a specific absorption rate (Hietanen et al, 2000;Croft et al, 2008;Fritzer et al, 2007;Kleinlogel et al, 2008aKleinlogel et al, , 2008bWagner et al, 1998, 2000, Borbe´ly et al, 1999Huber et al, 2003;Maby et al, 2004Maby et al, , 2005Maby et al, , 2006Freude et al, 1998;Hamblin et al, 2006;Jech et al, 2001;Perentos et al, 2007;Regel et al, 2007aRegel et al, , 2007bHuber et al, 2000Huber et al, , 2002Loughran et al, 2005;Hung et al, 2007;Stefanics et al, 2007;Parazzini et al, 2007;Hinrichs and Heinze, 2004), as if it were true that the extent of the ability of the EMF to heat water was a proper description of their independent variable-it was not. The specific absorption rate has been adopted by regulatory agencies to compare the outputs of mobile phones, but no authority has used it to explain their neurophysiological consequences.…”

“…Nokia (Fritzer et al, 2007)[À] Radio R. (Perentos et al, 2007)[À] Radiofrequency R. Center (Arai et al, 2003)[À], (Yuasa et al, 2006)[À], (Terao et al, 2007)[À], (Inomata-Terada et al, 2007)[À]…”

“…They also did not discuss the potential artifacts due to electrode pick-up. Fritzer et al (2007) investigated whether night-long EMF exposure affected the spectral power in ten subjects using a separate control group, but found no fieldinduced changes in power at any frequency in either REM or non REM sleep. The failure to use the exposed subjects as their own controls was a serious error.…”