Exposure to ELF EMF during Lessons in Secondary Schools

2017 · Mixed · Low evidence

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MixedLow evidencePaper 2183

In 60 classrooms across three secondary schools, spot measurements during class hours found ELF-EMF exposure levels lower than ICNIRP guidelines. However, 21.67% of classrooms had magnetic field strength above 0.2 µT, and main sources were electrical equipmen…

Study snapshot

Publicationmanual · 2017

Study typecross_sectional

Reported directionMixed

Evidence ratingLow

Abstract

Exposure to ELF EMF during Lessons in Secondary Schools Silangam W, Yoosook W, Kongtip P, Kongtawelert A, Theppeang K. EXPOSURE TO EXTREMELY LOW FREQUENCY ELECTROMAGNETIC FIELDS DURING LESSONS IN SECONDARY SCHOOLS. Radiat Prot Dosimetry. 2017 Dec 5:1-5. doi: 10.1093/rpd/ncx266. Abstract Schools are a significant location where children are exposed to electromagnetic fields (EMFs), which may cause adverse health effects. This cross-sectional study aimed to examine exposure levels to extremely low frequency magnetic fields (ELF-MFs) with a range of 5 Hz-32 kHz, and ELF-electric fields (ELF-EFs) with a range of 5 Hz-2 kHz in secondary schools in Bangkok, Thailand. This study was conducted in 60 classrooms from three schools during class hours. Spot measurements were taken with a Narda EFA 300 field analyzer to evaluate exposure levels. This study showed that ELF-EMF exposure levels are lower than ICNIRP guidelines, while 21.67% of classrooms had a magnetic field strength above 0.2 μT, and the main sources of ELF-EMFs were electrical equipment and electrical wiring. Future studies should measure ELF-EMF levels in other areas and evaluate the effects of long term exposure to ELF-EMFs on children's health. ncbi.nlm.nih.gov

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 typecross_sectional

Effect directionmixed

PopulationSecondary school classrooms in Bangkok, Thailand (children/students present during lessons)

Sample size60

ExposureELF · during class hours (spot measurements)

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

ELF magnetic field exposure levels (5 Hz–32 kHz)
ELF electric field exposure levels (5 Hz–2 kHz)
Proportion of classrooms with magnetic field strength >0.2 µT
Comparison with ICNIRP guidelines
Main sources of ELF-EMFs (electrical equipment, wiring)

Limitations

Cross-sectional design
Spot measurements (not long-term/personal exposure)
Limited to 60 classrooms in three schools in Bangkok, Thailand
No health outcomes assessed

View raw extracted JSON

{
  "study_type": "cross_sectional",
  "exposure": {
    "band": "ELF",
    "source": "secondary school classrooms (electrical equipment and electrical wiring)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "during class hours (spot measurements)"
  },
  "population": "Secondary school classrooms in Bangkok, Thailand (children/students present during lessons)",
  "sample_size": 60,
  "outcomes": [
    "ELF magnetic field exposure levels (5 Hz–32 kHz)",
    "ELF electric field exposure levels (5 Hz–2 kHz)",
    "Proportion of classrooms with magnetic field strength >0.2 µT",
    "Comparison with ICNIRP guidelines",
    "Main sources of ELF-EMFs (electrical equipment, wiring)"
  ],
  "main_findings": "In 60 classrooms across three secondary schools, spot measurements during class hours found ELF-EMF exposure levels lower than ICNIRP guidelines. However, 21.67% of classrooms had magnetic field strength above 0.2 µT, and main sources were electrical equipment and electrical wiring.",
  "effect_direction": "mixed",
  "limitations": [
    "Cross-sectional design",
    "Spot measurements (not long-term/personal exposure)",
    "Limited to 60 classrooms in three schools in Bangkok, Thailand",
    "No health outcomes assessed"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF",
    "magnetic fields",
    "electric fields",
    "secondary schools",
    "classrooms",
    "children",
    "Bangkok",
    "Thailand",
    "ICNIRP",
    "Narda EFA 300",
    "spot measurements"
  ],
  "suggested_hubs": [
    {
      "slug": "school-wi-fi",
      "weight": 0.25,
      "reason": "School-based exposure assessment during lessons (though focused on ELF, not Wi‑Fi)."
    },
    {
      "slug": "who-icnirp",
      "weight": 0.55,
      "reason": "Findings explicitly compared to ICNIRP guidelines."
    }
  ]
}

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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: 10.1093/rpd/ncx266
PubMed: Not supplied

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