Influence of radiofrequency electromagnetic fields on brain activity, sleep and cognitive performance of older women

2019 · Mixed · Moderate evidence

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MixedModerate evidencePaper 1695

Study snapshot

Publicationmanual · 2019

Study typerandomized_trial

Reported directionMixed

Evidence ratingModerate

Abstract

Influence of radiofrequency electromagnetic fields on brain activity, sleep and cognitive performance of older women Danker-Hopfe H, Dorn H, Eggert T, Sauter C. [Influence of radiofrequency electromagnetic fields on brain activity, sleep and cognitive performance of older women.] Radiofrequency Electromagnetic Field (RF-EMF) Effects on Brain Activity During Sleep and Waking in Healthy Elderly Women Project 3614S30012. Federal Office for Radiation Protection (BfS). 2019, Departmental Research Reports on Nuclear Safety and Radiation Protection (BfS-RESFOR) 143/19: 1-226 Excerpts from Summary The aim of the present randomized, double-blind cross-over study was to investigate acute effects of radiofrequency electromagnetic fields (RF-EMF) emitted by GSM900 mobile phones and TETRA (BOS) handheld devices on the central nervous system (CNS). Possible effects on the sleeping brain as well as on the waking brain in resting state and under cognitive demand were studied.... In the present study three different exposure signals were applied: 1) Sham exposure with a partial body SAR value of 0 W/kg (averaged over 10 g of tissue), 2) GSM 900 exposure with a partial body SAR value of 2.0 W/kg (averaged over 10 g of tissue) and 3) TETRA exposure a partial body SAR value of 6.0 W/kg (averaged over 10 g of tissue).... Overall, 30 women with a mean age of 67.8 ± 5.7 years (range: 60-80 years) participated in the present study. At study nights subjects were exposed at the left side of the head for 30 min prior to sleep and afterwards for the duration of the whole night (7.5 hours). Sleep architecture, sleep spindle parameters and power spectra of the sleep EEG were analysed. Daytime assessments comprised the level of tonic alertness as measured by the pupillographic sleepiness test (PST), the alpha-attenuation test (AAT) and the resting state waking EEG with eyes closed. Phasic alertness was tested by several evoked potentials (readiness potential, contingent negative variation, slow potential arising from a visual monitoring task, and auditory evoked potentials: N1, P2, and P3) with and without behavioural measures like reaction times and number of correct responses. Additionally effects on selective attention, divided attention, vigilance and working memory were investigated. Prior to testing subjects were exposed for 30 min followed by tests with parallel EEG registration for a duration of around 2.5 hours. To avoid time of day effects, all tests were performed in the afternoon starting at approximately 03:00 p.m.... In the elderly women exposure effects on brain activity during sleep showed more statistically significant differences in the macrostructure of sleep under RF exposure than in younger men. These effects point to a sleep-consolidating effect of RF exposure. Analysis of the power spectra values revealed that GSM exposure mainly resulted in a statistically significant lower EEG power in higher frequency bands at frontal electrode positions in the sleep stages N2, N3 and NREM. On the other hand, TETRA exposure mainly affected the deep delta frequency band, with statistically significant increased EEG power in sleep stage N1 at frontal electrode positions and in sleep stage N2 and NREM also at posterior electrodes. These results can also be interpreted to reflect a sleep-consolidating effect of RF exposure. The spindle analysis revealed no important exposure- dependent variations in the investigated sleep spindle parameters. In summary, none of the observed effects can be interpreted in terms of a disturbed sleep under exposure. While the PST and the AAT did not reveal any evidence for an RF exposure effect on the tonic level of central nervous alertness, power spectra of the waking EEG was increased in the alpha frequency range following TETRA exposure. These slight physiological variations, however, are typically not reflected in parameters of phasic alertness (exception: Contingent Negative Variation and P300 where results indicate a more efficient information processing under GSM exposure). With some exceptions [increased reaction time (mean + median) under GSM exposure in the first part of the vigilance task as well as increased reaction time (median) under GSM and TETRA exposure in the selective attention task] no systematic exposure related differences were observed for the three attention components: vigilance, selective and divided attention. There were also no systematic effects on working memory. A pre-post exposure comparison of mood and symptoms revealed only slight variation in relation to exposure. However, with one exception, the study night questionnaire outcome parameters, which were affected by exposure, were exclusively attributable to subjective sleep perception and can be interpreted as "better sleep" under RF exposure. These subjective assessments correspond to the observations for the objectively measured sleep parameters. Results of thermal perception suggest that the subjects were neither influenced nor unblinded due to a possible heating from the antenna. Overall the data indicate that brain activity as measured by power spectra of the wake and of the sleep EEG may differ between exposure conditions. This is in line with several other study results in this specific field of research. The slight physiological changes, however, are typically not reflected by behavioural measures and symptoms. Moreover, in particular the sleep data shows that the effects seen in elderly women differ significantly from those of young men. Whether these differences are age- and / or gender-specific can only be answered when the data of a study in elderly men (60 to 80 years) is analyzed. So far results refer to the group level. Analyses at the individual level, which can be performed based on multiple assessments per exposure condition and subject, are still pending. Open access paper (in German): doris.bfs.de 2019013117414/3/BfS_2019_3614S30012.pdf

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typerandomized_trial

Effect directionmixed

PopulationHealthy elderly women (60–80 years)

Sample size30

ExposureRF · 900 MHz · 2 W/kg · 30 min prior to sleep plus whole night (~7.5 h) during study nights; daytime: 30 min prior to testing plus ~2.5 h testing

Evidence strengthModerateConfidence: 74% · Peer reviewed: unknown

Main findings

In 30 older women, RF-EMF exposure (GSM900 at partial-body SAR 2.0 W/kg; TETRA at partial-body SAR 6.0 W/kg) produced statistically significant differences in sleep macrostructure and sleep EEG power spectra compared with sham, interpreted by the authors as sleep-consolidating and not as disturbed sleep; spindle parameters showed no important exposure-dependent variations. Tonic alertness measures (PST, AAT) showed no evidence of an exposure effect, while waking EEG alpha power increased after TETRA exposure and some evoked-potential results suggested more efficient information processing under GSM exposure; behavioural performance showed no systematic exposure-related differences aside from some increased reaction times in parts of vigilance and selective attention tasks. Subjective sleep perception outcomes affected by exposure were interpreted as better sleep under RF exposure, and thermal perception suggested participants were not unblinded by heating.

Outcomes measured

Sleep architecture
Sleep spindle parameters
Sleep EEG power spectra
Tonic alertness (PST, AAT)
Resting-state waking EEG power spectra
Phasic alertness (evoked potentials: readiness potential, CNV, slow potential from visual monitoring task, auditory evoked potentials N1, P2, P3; P300)
Reaction time and correct responses
Selective attention
Divided attention
Vigilance
Working memory
Mood and symptoms (pre-post exposure)
Subjective sleep perception (study night questionnaire)
Thermal perception (blinding/heating)

Limitations

Report excerpts only; full methods/results not fully provided in abstract text
Group-level results reported; individual-level analyses stated as pending
Comparisons to younger men mentioned but details not provided here
Journal/peer-review status not stated (government research report)

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone / handheld device",
    "frequency_mhz": 900,
    "sar_wkg": 2,
    "duration": "30 min prior to sleep plus whole night (~7.5 h) during study nights; daytime: 30 min prior to testing plus ~2.5 h testing"
  },
  "population": "Healthy elderly women (60–80 years)",
  "sample_size": 30,
  "outcomes": [
    "Sleep architecture",
    "Sleep spindle parameters",
    "Sleep EEG power spectra",
    "Tonic alertness (PST, AAT)",
    "Resting-state waking EEG power spectra",
    "Phasic alertness (evoked potentials: readiness potential, CNV, slow potential from visual monitoring task, auditory evoked potentials N1, P2, P3; P300)",
    "Reaction time and correct responses",
    "Selective attention",
    "Divided attention",
    "Vigilance",
    "Working memory",
    "Mood and symptoms (pre-post exposure)",
    "Subjective sleep perception (study night questionnaire)",
    "Thermal perception (blinding/heating)"
  ],
  "main_findings": "In 30 older women, RF-EMF exposure (GSM900 at partial-body SAR 2.0 W/kg; TETRA at partial-body SAR 6.0 W/kg) produced statistically significant differences in sleep macrostructure and sleep EEG power spectra compared with sham, interpreted by the authors as sleep-consolidating and not as disturbed sleep; spindle parameters showed no important exposure-dependent variations. Tonic alertness measures (PST, AAT) showed no evidence of an exposure effect, while waking EEG alpha power increased after TETRA exposure and some evoked-potential results suggested more efficient information processing under GSM exposure; behavioural performance showed no systematic exposure-related differences aside from some increased reaction times in parts of vigilance and selective attention tasks. Subjective sleep perception outcomes affected by exposure were interpreted as better sleep under RF exposure, and thermal perception suggested participants were not unblinded by heating.",
  "effect_direction": "mixed",
  "limitations": [
    "Report excerpts only; full methods/results not fully provided in abstract text",
    "Group-level results reported; individual-level analyses stated as pending",
    "Comparisons to younger men mentioned but details not provided here",
    "Journal/peer-review status not stated (government research report)"
  ],
  "evidence_strength": "moderate",
  "confidence": 0.74,
  "peer_reviewed_likely": "unknown",
  "keywords": [
    "RF-EMF",
    "GSM900",
    "TETRA",
    "BOS",
    "sleep EEG",
    "waking EEG",
    "sleep architecture",
    "sleep spindles",
    "alertness",
    "cognitive performance",
    "elderly women",
    "randomized double-blind cross-over",
    "SAR"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.25,
      "reason": "Human experimental study of RF exposure with SAR values relevant to guideline discussions."
    },
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Includes TETRA (BOS) handheld device exposure, commonly used in occupational/public-safety contexts."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

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