Assessment of extremely low frequency magnetic field exposure from GSM mobile phones.

Bioelectromagnetics · 2014 · Unclear · Low evidence

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UnclearLow evidencePaper 4564

Study snapshot

PublicationBioelectromagnetics · 2014

Study typeexposure_assessment

Reported directionUnclear

Evidence ratingLow

Abstract

Although radio frequency (RF) electromagnetic fields emitted by mobile phones have received much attention, relatively little is known about the extremely low frequency (ELF) magnetic fields emitted by phones. This paper summarises ELF magnetic flux density measurements on global system for mobile communications (GSM) mobile phones, conducted as part of the MOBI-KIDS epidemiological study. The main challenge is to identify a small number of generic phone models that can be used to classify the ELF exposure for the different phones reported in the study. Two-dimensional magnetic flux density measurements were performed on 47 GSM mobile phones at a distance of 25 mm. Maximum resultant magnetic flux density values at 217 Hz had a geometric mean of 221 (+198/-104) nT. Taking into account harmonic data, measurements suggest that mobile phones could make a substantial contribution to ELF exposure in the general population. The maximum values and easily available variables were poorly correlated. However, three groups could be defined on the basis of field pattern indicating that manufacturers and shapes of mobile phones may be the important parameters linked to the spatial characteristics of the magnetic field, and the categorization of ELF magnetic field exposure for GSM phones in the MOBI-KIDS study may be achievable on the basis of a small number of representative phones. Such categorization would result in a twofold exposure gradient between high and low exposure based on type of phone used, although there was overlap in the grouping.

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 typeexposure_assessment

Effect directionunclear

PopulationNot supplied

Sample size47

ExposureELF

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Two-dimensional magnetic flux density measurements on 47 GSM mobile phones at 25 mm found maximum resultant magnetic flux density values at 217 Hz with a geometric mean of 221 (+198/-104) nT. Maximum values and easily available variables were poorly correlated, but three groups could be defined based on field pattern, suggesting categorization of ELF exposure for MOBI-KIDS may be achievable using a small number of representative phones, yielding about a twofold exposure gradient between high and low exposure groups (with overlap).

Outcomes measured

ELF magnetic flux density (resultant) at 217 Hz
2D magnetic flux density field patterns at 25 mm distance
Correlation of maximum flux density with easily available phone variables
Exposure categorization/grouping for MOBI-KIDS phone models

Limitations

Measurements were performed at a single stated distance (25 mm).
Maximum flux density values were poorly correlated with easily available variables, complicating exposure classification.
Exposure groupings showed overlap.

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "ELF",
    "source": "mobile phone (GSM)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": 47,
  "outcomes": [
    "ELF magnetic flux density (resultant) at 217 Hz",
    "2D magnetic flux density field patterns at 25 mm distance",
    "Correlation of maximum flux density with easily available phone variables",
    "Exposure categorization/grouping for MOBI-KIDS phone models"
  ],
  "main_findings": "Two-dimensional magnetic flux density measurements on 47 GSM mobile phones at 25 mm found maximum resultant magnetic flux density values at 217 Hz with a geometric mean of 221 (+198/-104) nT. Maximum values and easily available variables were poorly correlated, but three groups could be defined based on field pattern, suggesting categorization of ELF exposure for MOBI-KIDS may be achievable using a small number of representative phones, yielding about a twofold exposure gradient between high and low exposure groups (with overlap).",
  "effect_direction": "unclear",
  "limitations": [
    "Measurements were performed at a single stated distance (25 mm).",
    "Maximum flux density values were poorly correlated with easily available variables, complicating exposure classification.",
    "Exposure groupings showed overlap."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF",
    "magnetic field",
    "magnetic flux density",
    "GSM",
    "mobile phones",
    "217 Hz",
    "MOBI-KIDS",
    "exposure assessment",
    "categorization"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.2,
      "reason": "Exposure assessment of ELF fields from mobile phones may be relevant to guideline discussions, though no policy content is stated."
    }
  ]
}

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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.21827
PubMed: 24203762

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