RF Safe

Effects of exposure to electromagnetic fields emitted by GSM 900 and WCDMA mobile phones on cognitive function in young male subjects.

Bioelectromagnetics · 2011 · No effect · Moderate evidence

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No effectModerate evidencePaper 4340

Initial univariate comparisons showed some significant changes in vigilance and divided attention tests during GSM 900 and WCDMA exposure compared to sham, but after correction for multiple testing, only time-of-day effects remained significant. Overall, no e…

Study snapshot

PublicationBioelectromagnetics · 2011
Study typerandomized_trial
Reported directionNo effect
Evidence ratingModerate

Abstract

Results of studies on the possible effects of electromagnetic fields emitted by mobile phones on cognitive functions are contradictory, therefore, possible effects of long-term (7 h 15 min) electromagnetic field (EMF) exposure to handset-like signals of Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA) on attention and working memory were studied. The sample comprised 30 healthy male subjects (mean ± SD: 25.3 ± 2.6 years), who were tested on nine study days in which they were exposed to three exposure conditions (sham, GSM 900 and WCDMA) in a randomly assigned and balanced order. All tests were presented twice (morning and afternoon) on each study day within a fixed timeframe. Univariate comparisons revealed significant changes when subjects were exposed to GSM 900 compared to sham, only in the vigilance test. In the WCDMA exposure condition, one parameter in the vigilance and one in the test on divided attention were altered compared to sham. Performance in the selective attention test and the n-back task was not affected by GSM 900 or WCDMA exposure. Time-of-day effects were evident for the tests on divided and selective attention, as well as for working memory. After correction for multiple testing, only time-of-day effects remained significant in two tests, resulting in faster reactions in the afternoon trials. The results of the present study do not provide any evidence of an EMF effect on human cognition, but they underline the necessity to control for time of day.

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 directionno_effect
Population30 healthy young male subjects (mean age 25.3 years)
Sample size30
ExposureRF · 900 MHz · 7 hours 15 minutes
Evidence strengthModerateConfidence: 70% · Peer reviewed: yes

Main findings

Initial univariate comparisons showed some significant changes in vigilance and divided attention tests during GSM 900 and WCDMA exposure compared to sham, but after correction for multiple testing, only time-of-day effects remained significant. Overall, no evidence was found for EMF effects on cognitive function.

Outcomes measured

  • vigilance test performance
  • divided attention test performance
  • selective attention test performance
  • n-back task performance (working memory)

Limitations

  • Small sample size (30 subjects)
  • Only young healthy males studied
  • Single long exposure session per condition
  • Only cognitive tests assessed, no other health outcomes
View raw extracted JSON
{
  "study_type": "randomized_trial",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "7 hours 15 minutes"
  },
  "population": "30 healthy young male subjects (mean age 25.3 years)",
  "sample_size": 30,
  "outcomes": [
    "vigilance test performance",
    "divided attention test performance",
    "selective attention test performance",
    "n-back task performance (working memory)"
  ],
  "main_findings": "Initial univariate comparisons showed some significant changes in vigilance and divided attention tests during GSM 900 and WCDMA exposure compared to sham, but after correction for multiple testing, only time-of-day effects remained significant. Overall, no evidence was found for EMF effects on cognitive function.",
  "effect_direction": "no_effect",
  "limitations": [
    "Small sample size (30 subjects)",
    "Only young healthy males studied",
    "Single long exposure session per condition",
    "Only cognitive tests assessed, no other health outcomes"
  ],
  "evidence_strength": "moderate",
  "confidence": 0.7,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "GSM 900",
    "WCDMA",
    "mobile phone",
    "cognitive function",
    "attention",
    "working memory",
    "electromagnetic fields",
    "RF exposure"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "Study of cognitive effects from mobile phone RF exposure."
    }
  ]
}
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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.20623
PubMed: 21365662

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