Brain activity is influenced by RF EMF: The role of pulsemodulation parameters Peter Achermann University of Zurich Institute of Pharmacology and Toxicology Zurich Center for Integrative Human Physiology Neuroscience Center Zurich Questions Do radio frequency electromagnetic fields (RF EMF) have a biological effect? Thermal vs. non-thermal mechanism Long-term exposure to multiple sources of low intensity Analysis of the sleep EEG waking Wach µv 2 /Hz stage Stadium 2 2.5 s 5 µv spindle stage Stadium REM Schlaf sleep µv 2 s 2 Hz Aeschbach (995)
Spectral analysis of sleep EEG Applied fields Frequenz frequency [Hz] (Hz) Schlafstadien sleep stages W MT R 2 3 25 2 5 5 2 3 5 6 7 8 Stunden hours handset-like GSM signal (CF=.8) base-station-like GSM signal (CF=.2) continuous wave (cw) RF EMF (CF=.) sham (no field) SAR = W/kg (.2 W/kg, 5 W/kg) Effects of RF EMF on nonrem sleep EEG Pulse-modulated RF EMF affect nonrem sleep EEG base-station-like RF EMF SAR = W/kg handset-like RF EMF EEG power density (field % of sham) 2 Exposure during sleep Exposure prior to sleep experiment experiment 2 experiment 3 n=2 n=6 n=6 5 5 95 9 5 5 2 25 5 5 2 25 5 5 2 25 frequency (Hz) Borbély et al. 999 Huber et al. 2 Huber et al. 22
EEG power (%) Handset-like RF EMF affect waking and nonrem sleep EEG in waking before sleep onset 8 6 2 8 5 handset-like/sham pm/sham a c continuous wave/sham cw/sham b d.5. n=6 p-value n=5 Power in spindle frequency range increased in dose dependent manner in stage 2 sleep 5 95 9.5 p-value. SAR = W/kg 5 5 2 25 5 5 2 25 frequency (Hz) Huber et al. 22 Regel et al., 27 Summary & Conclusion () exposure to pulse-modulated RF EMF affects nonrem sleep EEG ( studies) (in a dose-dependent manner) pulse modulation critical for RF EMFinduced EEG effect effects outlast exposure non-thermal effect Summary & Conclusion (2) both hemispheres affected independent of side of exposure weak RF EMF ( /) are capable of inducing observed EEG effects may be ruled out (dose-response study) subcortical brain regions (e.g. thalamus) may be responsible for the EEG effect
Effects of RF EMF on Waking EEG Increased alpha activity 3 min after exposure after pulse-modulated RF EMF exposure PM / SH C3A2, eyes closed, n=2 CW / SH.3 min 3 min 6 min.3 min 3 min 6 min.2.2 Relative Power...9 Relative Power...9.8.8 5 6 7 8 9 2 3 5 Frequency [Hz] 5 6 7 8 9 2 3 5 Frequency [Hz] Regel et al., 27 Summary & Conclusion (3) Effect appeared and disappeared within 6-min time window after exposure pulse modulation critical for RF EMFinduced EEG effect Effects of RF EMF on regional cerebral blood flow non-thermal effect
SAR distribution handset-bstat handset-sham handset-like RF EMF increased rcbf in dorsolateral prefrontal cortex of exposed hemisphere b b z=6 z=36 z=- L R c a a regional cerebral blood flow 6 5 d db specific absorption rate -5 - -5-2 bstat-handset n=2 Huber et al., 25 Summary & conclusion () rcbf in waking affected by handset-like RF EMF base-station-like RF EMF similar to sham condition pulse-modulated RF EMF ( handset-like ) affects rcbf in exposed hemisphere crucial role of pulse modulation evidence for non-thermal effect SAR distribution affected region handset-like base-station-like RF EMF Effects of RF EMF on cognitive performance during exposure Increased accuracy in 3-back task after pulse-modulated RF EMF exposure Accuracy (%) 95 9 (a) -back 2-back 3-back * (b) -back 2-back 3-back - - Accuracy change (S2-S) n=2 85 S S2 - Regel et al., 27
Summary & conclusion (5) handset-like RF EMF affects accuracy in N-back task (load dependent) first indication of dose-response effect crucial role of pulse modulation effects on cognitive performance less consistent than EEG effects Summary & Conclusion exposure to pulse-modulated RF EMF affects brain physiology (EEG, rcbf, cognitive performance) effects outlast exposure pulse modulation appears crucial for RF EMF-induced effects non-thermal biological action underlying mechanisms unknown NRP 57 projects Critical field parameters ) Critical field parameters: Which low frequency modulation components are causing the observed changes in brain activity? 2) Site of interaction: Is the thalamus, a subcortical structure, involved in mediating observed effects 3) Sensitivity in early adolescence: Are adolescents particularly sensitive to RF EMF exposure? Exposure conditions: Hz pulse-modulation 27 Hz pulse-modulation Sham
crest factor = 8 crest factor = 32 SAR average = 2 W/kg Study design 3 subjects (male, right-handed, 2-26 years old, non-smokers) 2 nights per week for 3 weeks 3 exposure conditions (one per week; 3 min prior to sleep) in a double-blinded crossover design cognitive tasks during exposure (SRT, CRT, N- back) Polysomnographic recordings (EEG, EOG, EMG, ECG) during 8 h of post-exposure sleep Acknowledgments R. Huber M. Schmid S. Regel A. Bratic S. Loughran A.A. Borbély T. Graf M. Adam K. Cote R. Dürr B. Fuchs E. Gallmann J.M. Gottselig K. Jütz H.-P. Landolt D. Matter G. Tinguely E. Werth L. Wittmann IT IS: N. Kuster J. Schuderer M. Murbach S. Kühne PET Center: A. Buck V. Treyer University of Zürich Swiss National Science Foundation Human Frontier Science Program Swiss Research Foundation on Mobile Communication Swiss Federal Office of Public Health SWISSCOM