Cellphone radiation "trapped" in train carriages

Journal of the Physical Society of Japan · 2002 · Harm · Low evidence

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HarmLow evidencePaper 6816

Using a calculation based on train carriage geometry, window area, reflection, and cumulative emissions from multiple mobile phones, the study found that electromagnetic field levels in a train carriage could exceed the maximum exposure level recommended by I…

Study snapshot

PublicationJournal of the Physical Society of Japan · 2002

Study typeengineering

Reported directionHarm

Evidence ratingLow

Abstract

Passengers on packed trains could unwittingly be exposed to electromagnetic fields far higher than those recommended under international guidelines. The problem? Hordes of commuters all using their mobile phones at the same time. Tsuyoshi Hondou, a physicist from Tohoku University in Sendai, Japan, who is currently working at the Curie Institute in Paris, says Japanese commuter trains are often packed with people surfing the web on their mobile phones. The trend spurred him to find out what effect this had on the electromagnetic radiation in a train carriage. Starting with plans of a typical train carriage acquired from a Japanese train operator, Hondou worked out the ratio of window area to structural metal for a typical carriage. He then used this to work out what proportion of the microwave radiation from the cellphones would be transmitted out of a carriage through the windows and how much would be reflected back inside. Hondou then calculated how microwaves from mobile phones distributed throughout a train carriage would add together, much like light from different lamps would increase the overall illumination in a room. He found that when both reflection and the cumulative effect of the radio waves were taken into consideration, the resulting electromagnetic field in a train carriage could exceed the maximum exposure level recommended by the International Committee for Non-Ionising Radiation (ICNIRP).

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 typeengineering

Effect directionharm

PopulationPassengers in packed train carriages using mobile phones

Sample sizeNot supplied

Exposuremicrowave

Evidence strengthLowConfidence: 87% · Peer reviewed: yes

Main findings

Outcomes measured

Calculated electromagnetic field levels in train carriages relative to ICNIRP recommended maximum exposure levels

Limitations

Appears to be a theoretical/calculation-based analysis rather than direct measurement
No sample size or real-world exposure measurements are reported in the abstract
Frequency, phone output characteristics, and exposure duration are not specified in the abstract

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": "microwave",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Passengers in packed train carriages using mobile phones",
  "sample_size": null,
  "outcomes": [
    "Calculated electromagnetic field levels in train carriages relative to ICNIRP recommended maximum exposure levels"
  ],
  "main_findings": "Using a calculation based on train carriage geometry, window area, reflection, and cumulative emissions from multiple mobile phones, the study found that electromagnetic field levels in a train carriage could exceed the maximum exposure level recommended by ICNIRP.",
  "effect_direction": "harm",
  "limitations": [
    "Appears to be a theoretical/calculation-based analysis rather than direct measurement",
    "No sample size or real-world exposure measurements are reported in the abstract",
    "Frequency, phone output characteristics, and exposure duration are not specified in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.87,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "mobile phone",
    "train carriage",
    "microwave radiation",
    "reflection",
    "cumulative exposure",
    "ICNIRP",
    "public transport",
    "engineering model"
  ],
  "suggested_hubs": [
    {
      "slug": "who-icnirp",
      "weight": 0.91,
      "reason": "The abstract explicitly compares calculated exposure levels with ICNIRP recommended limits."
    }
  ]
}

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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: Not supplied
PubMed: Not supplied

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