Personal digital assistant (PDA) cell phone units produce elevated extremely-low frequency electromagnetic field emissions.

Bioelectromagnetics · 2007 · Unclear · Insufficient evidence

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UnclearInsufficient evidencePaper 5073

Study snapshot

PublicationBioelectromagnetics · 2007

Study typeexposure_assessment

Reported directionUnclear

Evidence ratingInsufficient

Abstract

Initial tests indicate that personal and occupational use of personal digital assistants (PDAs or palm-held wireless units) produce high intensity bursts of extremely-low frequency electromagnetic fields (ELF-EMF). These emissions could result in comparatively high ELF-EMF exposure in persons that carry a PDA close to the body (i.e., in a pocket or on a belt); or held to the head for cell phone conversations. ELF-EMF emissions of 10 microT were recorded on PDAs during normal office use over a 24 h test period. Results of ELF-EMF measurements show that email transmit and receive functions produce rapid, short-duration ELF-EMF spikes in the 2-10 microT range, each lasting several seconds to over a minute apparently depending on file download size. Some units produced spikes as high as 30-60 microT during email activities. Cell phone activity on PDAs produced continuously elevated ELF-EMF readings in the 0.5-1 microT range, as opposed to the rapid spiking pattern for email receipt and transmission. Switching the PDA unit from "OFF" to "ON" position resulted in single ELF-EMF pulses of over 90 microT on two units. Email downloads into the PDA can occur randomly throughout the day and night when the unit is "ON"; thus the user who wears the PDA may be receiving high-intensity ELF-EMF pulses throughout the day and night. The frequency of email traffic on the PDA, and the power switching unit (battery unit) may affect the frequency and intensity of ELF-EMF emissions.

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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 sizeNot supplied

ExposureELF · 24 h test period; spikes lasting several seconds to over a minute

Evidence strengthInsufficientConfidence: 74% · Peer reviewed: yes

Main findings

ELF-EMF emissions up to 10 microT were recorded on PDAs during normal office use over a 24 h period. Email transmit/receive produced rapid short-duration spikes in the 2–10 microT range, with some units producing spikes as high as 30–60 microT; switching from OFF to ON produced single pulses over 90 microT on two units. Cell phone activity produced continuously elevated readings in the 0.5–1 microT range.

Outcomes measured

ELF-EMF emission levels (microT) during PDA normal office use
ELF-EMF spikes during email transmit/receive
ELF-EMF levels during cell phone activity
ELF-EMF pulses when switching from OFF to ON

Limitations

Population and health outcomes were not assessed (emissions/exposure characterization only).
Sample size and number of PDA units tested are not reported in the abstract.
Measurement methods/instrumentation and exact frequency characteristics are not described in the abstract.

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "ELF",
    "source": "personal digital assistant (PDA) / palm-held wireless unit with cell phone and email functions",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "24 h test period; spikes lasting several seconds to over a minute"
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "ELF-EMF emission levels (microT) during PDA normal office use",
    "ELF-EMF spikes during email transmit/receive",
    "ELF-EMF levels during cell phone activity",
    "ELF-EMF pulses when switching from OFF to ON"
  ],
  "main_findings": "ELF-EMF emissions up to 10 microT were recorded on PDAs during normal office use over a 24 h period. Email transmit/receive produced rapid short-duration spikes in the 2–10 microT range, with some units producing spikes as high as 30–60 microT; switching from OFF to ON produced single pulses over 90 microT on two units. Cell phone activity produced continuously elevated readings in the 0.5–1 microT range.",
  "effect_direction": "unclear",
  "limitations": [
    "Population and health outcomes were not assessed (emissions/exposure characterization only).",
    "Sample size and number of PDA units tested are not reported in the abstract.",
    "Measurement methods/instrumentation and exact frequency characteristics are not described in the abstract."
  ],
  "evidence_strength": "insufficient",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "PDA",
    "personal digital assistant",
    "palm-held wireless unit",
    "ELF-EMF",
    "extremely-low frequency",
    "microtesla",
    "email transmit",
    "email receive",
    "cell phone activity",
    "power switching",
    "battery unit",
    "exposure assessment"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.42,
      "reason": "Abstract mentions personal and occupational use and measurements during normal office use."
    }
  ]
}

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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.20315
PubMed: 17357117

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