RF Safe

Modulation of brain functional connectivity by exposure to LTE (4G) cell phone radiation

2018 · Mixed · Low evidence

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MixedLow evidencePaper 1937

In a double-blind, crossover, randomized, counterbalanced design comparing real vs sham exposure, acute LTE EMF exposure (2.573 GHz; 30 min) was associated with statistically significant modulation of localized intra-regional connectivity and inter-regional c…

Study snapshot

Publicationmanual · 2018
Study typerandomized_trial
Reported directionMixed
Evidence ratingLow

Abstract

Modulation of brain functional connectivity by exposure to LTE (4G) cell phone radiation Wei Y, Yang J, Chen Z, Wu T, Lv B. Modulation of resting-state brain functional connectivity by exposure to acute fourth-generation long-term evolution electromagnetic field: An fMRI study. Bioelectromagnetics. Published online 18 December 2018 Abstract By now, the neurophysiological effect of electromagnetic field (EMF) exposure and its underlying regulating mechanisms are not well manifested. In this study, we aimed to investigate whether acute long-term evolution (LTE) EMF exposure could modulate brain functional connectivity using regional homogeneity (ReHo) method and seed-based analysis on resting-state functional magnetic resonance imaging (fMRI). We performed the LTE- EMF exposure experiment and acquired the resting-state brain activities before and after EMF exposure. Then we applied ReHo index to characterize the localized functional connectivity and seed-based method to evaluate the inter-regional functional connectivity. Statistical comparisons were conducted to identify the possible evidence of brain functional connectivity modulation induced by the acute LTE-EMF exposure. We found that the acute LTE‐EMF exposure modulated localized intra‐regional connectivity (p < 0.05, AlphaSim corrected, voxel size ≥ 18) and inter‐regional connectivity in some brain regions (p < 0.05, AlphaSim corrected, voxel size ≥ 18). Our results may indicate that the approaches relying on network-level inferences could provide deeper insight into the acute effect on human functional activity induced by LTE-EMF exposure. Excerpts "To eliminate study biases, we employed a double-blind, crossover, randomized, and counterbalanced design. Each participant underwent two experimental sessions including real exposure and sham exposure, which were separated by 1 day....The time‐division LTE signal (2.573 GHz) was produced by a signal generator (CMW500, R&S, Munich, Germany) using a standard formulation for LTE signals....The power delivered to the standard dipole of 2.6 GHz (D2600V2, Speag, Zurich, Switzerland) was 24 dBm (mean value), which was equivalent to a theoretical maximal emission by an LTE terminal. The experiments were conducted in a shielding room to avoid the influence of environmental EMF. Each exposure session lasted for 30 min." "Numerical simulations that yielded spatial peak SAR averaging over 10 g tissues for the subjects was 0.98 ± 0.27 W/kg, with a maximal value of 1.52 W/kg, which was below the safety limits [ICNIRP, 1998]." "In our previous studies, we found that LTE-EMF exposure depressed the amplitude of spontaneous low frequency fluctuations (ALFFs) in some brain regions [Lv et al., 2014], such as those surrounding the left superior temporal gyrus and middle temporal gyrus (STG_L and MTG_L), right superior temporal gyrus (STG_R), right medial frontal gyrus, and right paracentral lobule (MFG_R and PCL_R). In the present study, we found new evidence that acute LTE‐EMF exposures lasting for 30 min modulated brain functional connectivity including not only localized intraregional connectivity, but also interregional connectivity." "Conclusion. Our results may indicate that approaches relying on network-level inferences can provide deeper insights into the acute effects of LTE-EMF exposure with intensities below the current safety limits on human functional connectivity. In the future, we need to investigate the evolution of the effect over time." onlinelibrary.wiley.com

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 directionmixed
PopulationHuman participants (resting-state fMRI study; participant characteristics not specified in provided text)
Sample sizeNot supplied
ExposureRF · 2573 MHz · 0.98 W/kg · 30 min (acute)
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In a double-blind, crossover, randomized, counterbalanced design comparing real vs sham exposure, acute LTE EMF exposure (2.573 GHz; 30 min) was associated with statistically significant modulation of localized intra-regional connectivity and inter-regional connectivity in some brain regions (p<0.05, AlphaSim corrected; voxel size ≥18).

Outcomes measured

  • Resting-state brain functional connectivity (regional homogeneity/ReHo; seed-based inter-regional connectivity)

Limitations

  • Sample size and participant demographics not provided in the supplied abstract/excerpts
  • Specific brain regions showing connectivity changes are not fully detailed in the supplied abstract/excerpts
  • Short-term (acute) exposure only; evolution over time not assessed
View raw extracted JSON
{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 2573,
    "sar_wkg": 0.98,
    "duration": "30 min (acute)"
  },
  "population": "Human participants (resting-state fMRI study; participant characteristics not specified in provided text)",
  "sample_size": null,
  "outcomes": [
    "Resting-state brain functional connectivity (regional homogeneity/ReHo; seed-based inter-regional connectivity)"
  ],
  "main_findings": "In a double-blind, crossover, randomized, counterbalanced design comparing real vs sham exposure, acute LTE EMF exposure (2.573 GHz; 30 min) was associated with statistically significant modulation of localized intra-regional connectivity and inter-regional connectivity in some brain regions (p<0.05, AlphaSim corrected; voxel size ≥18).",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size and participant demographics not provided in the supplied abstract/excerpts",
    "Specific brain regions showing connectivity changes are not fully detailed in the supplied abstract/excerpts",
    "Short-term (acute) exposure only; evolution over time not assessed"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "LTE",
    "4G",
    "RF-EMF",
    "2.573 GHz",
    "fMRI",
    "resting-state",
    "functional connectivity",
    "ReHo",
    "seed-based analysis",
    "double-blind",
    "crossover",
    "sham exposure",
    "SAR"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "LTE (4G) terminal-equivalent exposure with sham-controlled crossover design."
    }
  ]
}
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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: 10.1002/bem.22165
PubMed: Not supplied

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