Assessment of intermittent UMTS electromagnetic field effects on blood circulation in the human auditory region using a near-infrared system.

Bioelectromagnetics · 2012 · Mixed · Low evidence

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MixedLow evidencePaper 4456

Study snapshot

PublicationBioelectromagnetics · 2012

Study typerandomized_trial

Reported directionMixed

Evidence ratingLow

Abstract

The aim of the present study was to assess the potential effects of intermittent Universal Mobile Telecommunications System electromagnetic fields (UMTS-EMF) on blood circulation in the human head (auditory region) using near-infrared spectroscopy (NIRS) on two different timescales: short-term (effects occurring within 80 s) and medium-term (effects occurring within 80 s to 30 min). For the first time, we measured potential immediate effects of UMTS-EMF in real-time without any interference during exposure. Three different exposures (sham, 0.18 W/kg, and 1.8 W/kg) were applied in a controlled, randomized, crossover, and double-blind paradigm on 16 healthy volunteers. In addition to oxy-, deoxy-, and total haemoglobin concentrations ([O(2) Hb], [HHb], and [tHb], respectively), the heart rate (HR), subjective well-being, tiredness, and counting speed were recorded. During exposure to 0.18 W/kg, we found a significant short-term increase in Δ[O(2) Hb] and Δ[tHb], which is small (≈17%) compared to a functional brain activation. A significant decrease in the medium-term response of Δ[HHb] at 0.18 and 1.8 W/kg exposures was detected, which is in the range of physiological fluctuations. The medium-term ΔHR was significantly higher (+1.84 bpm) at 1.8 W/kg than for sham exposure. The other parameters showed no significant effects. Our results suggest that intermittent exposure to UMTS-EMF has small short- and medium-term effects on cerebral blood circulation and HR.

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Study typerandomized_trial

Effect directionmixed

Population16 healthy volunteers

Sample size16

ExposureRF · short-term (within 80 s) and medium-term (80 s to 30 min); intermittent exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

In a randomized, double-blind crossover study with sham, 0.18 W/kg, and 1.8 W/kg UMTS-EMF exposures, 0.18 W/kg produced a significant short-term increase in Δ[O2Hb] and Δ[tHb] (reported as small, ~17% of functional brain activation). Medium-term Δ[HHb] decreased significantly at both 0.18 and 1.8 W/kg (reported as within physiological fluctuations), and medium-term ΔHR was significantly higher (+1.84 bpm) at 1.8 W/kg versus sham; other measures showed no significant effects.

Outcomes measured

Near-infrared spectroscopy (NIRS) measures in auditory region: oxyhaemoglobin concentration ([O2Hb])
Near-infrared spectroscopy (NIRS) measures in auditory region: deoxyhaemoglobin concentration ([HHb])
Near-infrared spectroscopy (NIRS) measures in auditory region: total haemoglobin concentration ([tHb])
Heart rate (HR)
Subjective well-being
Tiredness
Counting speed

Limitations

Small sample size (n=16)
Frequency of UMTS exposure not reported in abstract
Exposure duration details per condition not fully specified beyond time windows
Outcomes limited to short- and medium-term physiological/subjective measures in the auditory region

View raw extracted JSON

{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "short-term (within 80 s) and medium-term (80 s to 30 min); intermittent exposure"
  },
  "population": "16 healthy volunteers",
  "sample_size": 16,
  "outcomes": [
    "Near-infrared spectroscopy (NIRS) measures in auditory region: oxyhaemoglobin concentration ([O2Hb])",
    "Near-infrared spectroscopy (NIRS) measures in auditory region: deoxyhaemoglobin concentration ([HHb])",
    "Near-infrared spectroscopy (NIRS) measures in auditory region: total haemoglobin concentration ([tHb])",
    "Heart rate (HR)",
    "Subjective well-being",
    "Tiredness",
    "Counting speed"
  ],
  "main_findings": "In a randomized, double-blind crossover study with sham, 0.18 W/kg, and 1.8 W/kg UMTS-EMF exposures, 0.18 W/kg produced a significant short-term increase in Δ[O2Hb] and Δ[tHb] (reported as small, ~17% of functional brain activation). Medium-term Δ[HHb] decreased significantly at both 0.18 and 1.8 W/kg (reported as within physiological fluctuations), and medium-term ΔHR was significantly higher (+1.84 bpm) at 1.8 W/kg versus sham; other measures showed no significant effects.",
  "effect_direction": "mixed",
  "limitations": [
    "Small sample size (n=16)",
    "Frequency of UMTS exposure not reported in abstract",
    "Exposure duration details per condition not fully specified beyond time windows",
    "Outcomes limited to short- and medium-term physiological/subjective measures in the auditory region"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "UMTS",
    "RF-EMF",
    "intermittent exposure",
    "near-infrared spectroscopy",
    "NIRS",
    "auditory region",
    "cerebral blood circulation",
    "oxyhaemoglobin",
    "deoxyhaemoglobin",
    "total haemoglobin",
    "heart rate",
    "double-blind",
    "randomized crossover"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.25,
      "reason": "Human RF-EMF (UMTS) exposure study relevant to health-effects evidence base often 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: 10.1002/bem.20682
PubMed: 21695708

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