Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi

2017 · Unclear · Low evidence

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UnclearLow evidencePaper 2196

Study snapshot

Publicationmanual · 2017

Study typeexposure_assessment

Reported directionUnclear

Evidence ratingLow

Abstract

Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi Lena K. Hedendahl, Michael Carlberg, Tarmo Koppel, Lennart Hardell. Measurements of Radiofrequency Radiation with a Body-Borne Exposimeter in Swedish Schools with Wi-Fi. Front. Public Health, 20 November 2017 | doi.org Introduction: Wireless access to the Internet is now commonly used in schools. Many schools give each student their own laptop and utilize the laptops and wireless fidelity (Wi-Fi) connection for educational purposes. Most children also bring their own mobile phones to school. Since children are obliged by law to attend school, a safe environment is important. Lately, it has been discussed if radiofrequency (RF) radiation can have long-term adverse effects on children's health. Method: This study conducted exposimetric measurements in schools to assess RF emissions in the classroom by measuring the teachers' RF exposure in order to approximate the children's exposure. Teachers in grades 7-12 carried a body-borne exposimeter, EME-Spy 200, in school during 1-4 days of work. The exposimeter can measure 20 different frequency bands from 87 to 5,850 MHz. Results: Eighteen teachers from seven schools participated. The mean exposure to RF radiation ranged from 1.1 to 66.1 µW/m2. The highest mean level, 396.6 µW/m2, occurred during 5 min of a lesson when the teacher let the students stream and watch YouTube videos. Maximum peaks went up to 82,857 µW/m2 from mobile phone uplink. Discussion: Our measurements are in line with recent exposure studies in schools in other countries. The exposure levels varied between the different Wi-Fi systems, and if the students were allowed to use their own smartphones on the school's Wi-Fi network or if they were connected to GSM/3G/4G base stations outside the school. An access point over the teacher's head gave higher exposure compared with a school with a wired Internet connection for the teacher in the classroom. All values were far below International Commission on Non-Ionizing Radiation Protection's reference values, but most mean levels measured were above the precautionary target level of 3-6 µW/m2 as proposed by the Bioinitiative Report. The length of time wireless devices are used is an essential determinant in overall exposure. Measures to minimize children's exposure to RF radiation in school would include preferring wired connections, allowing laptops, tablets and mobile phones only in flight mode and deactivating Wi-Fi access points, when not used for learning purposes. In Conclusion 1. The ICNIRP guidelines are based on short-term heating (thermal) effects, and are therefore not relevant to decide on the appropriateness of long-term exposure. 2. The environmental exposure to RF radiation in some schools is higher than reported levels for non-thermal biological effects. In order to reduce children's exposure to RF radiation, schools should prefer wired network connections, allow laptop, tablets, and mobile phone usage only in flight mode and deactivate Wi-Fi access points when internet is not needed for learning purposes. Open source paper: frontiersin.org

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

PopulationTeachers (grades 7–12) in Swedish schools (used to approximate children’s exposure)

Sample size18

ExposureRF · Teachers carried a body-borne exposimeter during 1–4 workdays; includes 5-min lesson interval with highest mean exposure reported.

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Eighteen teachers from seven schools wore an EME-Spy 200 exposimeter (87–5,850 MHz) for 1–4 workdays. Mean RF exposure ranged from 1.1 to 66.1 µW/m², with the highest mean level (396.6 µW/m²) during 5 minutes of a lesson when students streamed YouTube; maximum peaks reached 82,857 µW/m² from mobile phone uplink. The authors state all values were far below ICNIRP reference values, while most mean levels were above the Bioinitiative Report precautionary target level of 3–6 µW/m².

Outcomes measured

Personal RF exposure levels (µW/m²) across 20 frequency bands (87–5,850 MHz)
Mean exposure levels by school/conditions
Maximum peak exposure levels
Contextual determinants of exposure (Wi-Fi system, smartphone use on Wi-Fi vs GSM/3G/4G, access point placement, wired vs wireless connection)

Limitations

Exposure was measured on teachers and used to approximate children’s exposure (not direct child measurements).
No health outcomes were measured; study focuses on exposure characterization.
Specific frequency-by-frequency results are not provided in the abstract (only overall exposure summaries and one source attribution for peaks).

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "RF",
    "source": "school wi-fi and mobile phones (uplink)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "Teachers carried a body-borne exposimeter during 1–4 workdays; includes 5-min lesson interval with highest mean exposure reported."
  },
  "population": "Teachers (grades 7–12) in Swedish schools (used to approximate children’s exposure)",
  "sample_size": 18,
  "outcomes": [
    "Personal RF exposure levels (µW/m²) across 20 frequency bands (87–5,850 MHz)",
    "Mean exposure levels by school/conditions",
    "Maximum peak exposure levels",
    "Contextual determinants of exposure (Wi-Fi system, smartphone use on Wi-Fi vs GSM/3G/4G, access point placement, wired vs wireless connection)"
  ],
  "main_findings": "Eighteen teachers from seven schools wore an EME-Spy 200 exposimeter (87–5,850 MHz) for 1–4 workdays. Mean RF exposure ranged from 1.1 to 66.1 µW/m², with the highest mean level (396.6 µW/m²) during 5 minutes of a lesson when students streamed YouTube; maximum peaks reached 82,857 µW/m² from mobile phone uplink. The authors state all values were far below ICNIRP reference values, while most mean levels were above the Bioinitiative Report precautionary target level of 3–6 µW/m².",
  "effect_direction": "unclear",
  "limitations": [
    "Exposure was measured on teachers and used to approximate children’s exposure (not direct child measurements).",
    "No health outcomes were measured; study focuses on exposure characterization.",
    "Specific frequency-by-frequency results are not provided in the abstract (only overall exposure summaries and one source attribution for peaks)."
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "school",
    "Wi-Fi",
    "radiofrequency radiation",
    "exposimeter",
    "EME-Spy 200",
    "teachers",
    "children",
    "mobile phone uplink",
    "ICNIRP",
    "Bioinitiative",
    "Sweden"
  ],
  "suggested_hubs": [
    {
      "slug": "school-wi-fi",
      "weight": 0.95,
      "reason": "RF exposure measurements in schools with Wi‑Fi; discusses determinants and mitigation in school settings."
    },
    {
      "slug": "who-icnirp",
      "weight": 0.6,
      "reason": "Compares measured levels to ICNIRP reference values and discusses guideline relevance."
    }
  ]
}

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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: 10.3389/fpubh.2017.00279
PubMed: Not supplied

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