Radiofrequency Electromagnetic Fields: Effects on the Sleeping Brain

Transcription

1 Radiofrequency Electromagnetic Fields: Effects on the Sleeping Brain Sarah Loughran Australian Centre for Electromagnetic Bioeffects Research Wollongong University 8th ICNIRP International NIR Workshop Cape Town, South Africa, 9-11 May 2016

2 Mobile Phones and Health: What is the Issue? Increasing mobile phone use increase in concern and demand for scientific research Particular focus on potential effects of RF EMF on the human brain Possibility of biological effects below current exposure limits/guidelines Currently no biophysical mechanisms capable of justifying these concerns

3 Mobile Phones and Health: Addressing the Issue Why Use EEG? Simple, non-invasive technique that reflects synchronous activity in cortical neurons Well-characterised Correlated with vigilance state and cognitive functioning/processing during waking Reflects different stages of sleep (non-rem) sleep Aeschbach (1995)

4 Why Use the EEG?: High Intra-Individual Stability Waking NREM Sleep Napflin et al Buckelmüller et al., 2006

5 RF EMF and the Brain: Effects on the Sleeping Brain

6 Early Reports: Effects on Sleep EEG and Sleep Architecture Early Report of Effects on Sleep Klaus Mann & Joachim Röschke

7 Consistent Effects: RF EMF Exposure and the Sleep EEG

8 RF EMF Exposure Effects: Independently Replicated & Sensitive to Individual Variability Loughran et al., 2005 Loughran et al., 2012

9 Underlying Mechanisms of RF EMF Sleep EEG Effects: Pulse Modulation Characteristics Absolute Power Spectra Relative Power Spectra Schmid*, Loughran*, et al., 2012

10 Underlying Mechanisms of RF EMF Sleep EEG Effects: Site of Interaction Sleep (All Night) Sleep (Last Third of Night) Loughran et al., in prep

11 RF EMF and Sleep EEG: Summary of Previous Research REM sleep NREM sleep

12 RF EMF and the EEG: Why the Variation in Results? Differences in exposure parameters Exposure conditions often ill-defined Dosimetry not specified Single-blind conditions / no blinding Variable exposure conditions across studies (studies not comparable) Differences in study design Cognitive tasks Sleep measurements EEG recordings Between subjects vs. within subjects design Magnitude of effect Sample size Statistics Multiple comparisons Individual Variability

13 RF EMF and EEG: Consistent exposure-related effects Resting/Waking EEG Sleep EEG

14 RF EMF and the Brain: Major Uncertainties, Research Gaps & Current Research

15 RF EMF and the Brain: Consistent Effects, Consequences & Unknowns We know that there is an effect on brain function and neural activity, however: To date there has not been a demonstration of functional significance Underlying neurobiological mechanisms remain unknown General belief that the energy emitted is too small for a thermal response Argued that if there are non-thermal effects then it appears that these are not taken into account by current standards and guidelines As the only known RF biophysical mechanism (i.e. thermal) cannot currently explain this effect, it leaves RF Health Standards in doubt The lack of understanding raises the possibility that there are concomitant effects that do impact on health, but that are yet to be assessed Problematic for risk communication Relevance to health, long-term effects, and possible sensitive populations (e.g. children)???

16 RF EMF and the Brain: Sensitivity in Adolescence (Waking EEG) Loughran et al., 2013

17 Current Research: RF EMF and Sleep in Children and Adolescents

18 Current Research: Determine whether RF EMF within exposure limits affects thermoregulation Thermal Perfusion Suit, Finger Temp, Laser Doppler, Auditory Canal, Skin Temp, MAP, EEG, Cognition

19 Current Research: Determine whether RF EMF within exposure limits affects thermoregulation Results Suggest: 1) RF EMF within ICNIRP limits engages thermoregulatory processes 2) No evidence that RF EMF-induced EEG brain activity changes are non-thermal in nature Loughran et al., in prep

20 Other Current/Planned Research: RF EMF Thermoregulatory Mechanisms 1. Is the RF-thermoregulatory change due to core body temp change? 2. Does equivalent thermoregulatory change, temperature at skin, or temperature at cortex (applied/induced via non-rf sources, e.g. thermal perfusion suit, laser) lead to same change in brain activity? Sleep 1. Determining the influence of gender and circadian cycle on the EEG effect 2. Are there functional consequences of the Sleep EEG effect? Cortical Excitability, and Emotional Processing 1. Transcranial Magnetic Stimulation (TMS): does RF EMF exposure lead to changes in cortical excitability? 2. Are there effects of exposure to RF EMF on emotion/emotional processing? Effects on Cognitive Performance 1. Overcoming confounds in previous studies to determine whether RF EMF influences cognition Effects of Very Short and Intermittent RF EMF Exposure on Brain Activity IEI-EMF Provocation Case Studies 1. A novel approach to testing sensitive individuals

21 Acknowledgements University of Zurich Prof. Peter Achermann Dr. Marc Schmid Micheline Maire Dominik Benz Australian Centre for Radiofrequency Bioeffects Research (ACEBR) Prof. Rodney Croft Ray Mckenzie Prof. Andrew Wood Adam Verrender Anna Dalecki IT IS Foundation Prof. Niels Kuster Dr. Manuel Murbach

22 Thank you for your attention