RF Safe

The alteration of spontaneous low frequency oscillations caused by acute electromagnetic fields exposure.

Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology · 2014 · Harm · Low evidence

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HarmLow evidencePaper 4579

In a double-blind, crossover, randomized sham-controlled experiment, 30 min near-field LTE RF-EMF exposure with the source close to the right ear was associated with decreased ALFF in several brain regions (including bilateral superior temporal gyrus, left mi…

Study snapshot

PublicationClinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology · 2014
Study typerandomized_trial
Reported directionHarm
Evidence ratingLow

Abstract

OBJECTIVE: The motivation of this study is to evaluate the possible alteration of regional resting state brain activity induced by the acute radiofrequency electromagnetic field (RF-EMF) exposure (30min) of Long Term Evolution (LTE) signal. METHODS: We designed a controllable near-field LTE RF-EMF exposure environment. Eighteen subjects participated in a double-blind, crossover, randomized and counterbalanced experiment including two sessions (real and sham exposure). The radiation source was close to the right ear. Then the resting state fMRI signals of human brain were collected before and after the exposure in both sessions. We measured the amplitude of low frequency fluctuation (ALFF) and fractional ALFF (fALFF) to characterize the spontaneous brain activity. RESULTS: We found the decreased ALFF value around in left superior temporal gyrus, left middle temporal gyrus, right superior temporal gyrus, right medial frontal gyrus and right paracentral lobule after the real exposure. And the decreased fALFF value was also detected in right medial frontal gyrus and right paracentral lobule. CONCLUSIONS: The study provided the evidences that 30min LTE RF-EMF exposure modulated the spontaneous low frequency fluctuations in some brain regions. SIGNIFICANCE: With resting state fMRI, we found the alteration of spontaneous low frequency fluctuations induced by the acute LTE RF-EMF exposure.

Machine Enhanced Logic

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 directionharm
PopulationHuman subjects
Sample size18
ExposureRF · 30 min (acute)
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In a double-blind, crossover, randomized sham-controlled experiment, 30 min near-field LTE RF-EMF exposure with the source close to the right ear was associated with decreased ALFF in several brain regions (including bilateral superior temporal gyrus, left middle temporal gyrus, right medial frontal gyrus, and right paracentral lobule) compared with pre-exposure. Decreased fALFF was also detected in the right medial frontal gyrus and right paracentral lobule after real exposure.

Outcomes measured

  • Resting-state fMRI amplitude of low frequency fluctuation (ALFF)
  • Resting-state fMRI fractional ALFF (fALFF)
  • Regional spontaneous low frequency oscillations in specific brain regions

Limitations

  • Small sample size (18 subjects)
  • Acute exposure only (30 min); no long-term outcomes reported
  • Exposure metrics (e.g., frequency, SAR) not reported in the abstract
  • Outcomes are neuroimaging signal metrics; clinical relevance not established in the abstract
View raw extracted JSON
{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 min (acute)"
  },
  "population": "Human subjects",
  "sample_size": 18,
  "outcomes": [
    "Resting-state fMRI amplitude of low frequency fluctuation (ALFF)",
    "Resting-state fMRI fractional ALFF (fALFF)",
    "Regional spontaneous low frequency oscillations in specific brain regions"
  ],
  "main_findings": "In a double-blind, crossover, randomized sham-controlled experiment, 30 min near-field LTE RF-EMF exposure with the source close to the right ear was associated with decreased ALFF in several brain regions (including bilateral superior temporal gyrus, left middle temporal gyrus, right medial frontal gyrus, and right paracentral lobule) compared with pre-exposure. Decreased fALFF was also detected in the right medial frontal gyrus and right paracentral lobule after real exposure.",
  "effect_direction": "harm",
  "limitations": [
    "Small sample size (18 subjects)",
    "Acute exposure only (30 min); no long-term outcomes reported",
    "Exposure metrics (e.g., frequency, SAR) not reported in the abstract",
    "Outcomes are neuroimaging signal metrics; clinical relevance not established in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "LTE",
    "RF-EMF",
    "near-field exposure",
    "double-blind",
    "crossover",
    "randomized",
    "sham exposure",
    "resting-state fMRI",
    "ALFF",
    "fALFF",
    "spontaneous low frequency fluctuations"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.2,
      "reason": "Human experimental RF-EMF exposure study relevant to health evidence considered in guideline discussions."
    }
  ]
}
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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.

Identifiers and source

DOI: 10.1016/j.clinph.2013.07.018
PubMed: 24012322

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