Radiofrequency Radiation

2018 · Mixed · Low evidence

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MixedLow evidencePaper 2110

Study snapshot

Publicationmanual · 2018

Study typeexposure_assessment

Reported directionMixed

Evidence ratingLow

Abstract

Radiofrequency Radiation Numerical evaluation of human exposure to WiMax patch antenna in tablet or laptop Siervo B, Morelli MS, Landini L, Hartwig V. Numerical evaluation of human exposure to WiMax patch antenna in tablet or laptop. Bioelectromagnetics. 2018 Apr 30. doi: 10.1002/bem.22128. Abstract The use of wireless communication devices, such as tablets or laptops, is increasing among children. Only a few studies assess specific energy absorption rate (SAR) due to exposure from wireless-enabled tablets and laptops, in particular with Worldwide Interoperability for Microwave Access (WiMax) technology. This paper reports the estimation of the interaction between an E-shaped patch antenna (3.5 GHz) and human models, by means of finite-difference time-domain (FDTD) method. Specifically, four different human models (young adult male, young adult female, pre-teenager female, male child) in different exposure conditions (antenna at different distances from the human model, in different positions, and orientations) were considered and whole-body, 10 and 1 g local SAR and magnetic field value (Bmax) were evaluated. From our results, in some worst-case scenarios involving male and female children's exposure, the maximum radiofrequency energy absorption (hot spots) is located in more sensitive organs such as eye, genitals, and breast. Excerpts Worldwide Interoperability for Microwave Access (WiMax) is a communication system based on IEEE 802.16 [2004], belonging to fourth generation (4G) technology with well-known Long-term Evolution (LTE). In conclusion, the results of our study show the importance of simulating exposure taking into account the antenna-body mutual position for the exact localization of maximum SAR values ("hot spots"). Although the average SAR values do not exceed the recommended limits for all simulated exposure conditions except one, the maximum SAR values in some scenarios are located in more sensitive organs, which are the eyes, genitals, and breast. This is particularly important for children. Their entire organism is in a process of development and it is not possible to predict long-lasting problems that might occur as a result of exposure to EM fields at an early age. Nevertheless, recently Barnes and Greenenbaum [2016] presented possible theoretical mechanisms and experimental data concerning long-term exposures to RF magnetic fields, speculating that they can be responsible for changing in radical concentrations. Moreover, the values for the SAR reported here are expected to be in a range that could change the concentration of reactive oxygen species, and long-term exposures may be significant for some health effects [De Iuliis et al., 2009; Kang et al., 2014; Wang and Zhang, 2017]. Hence, until a more exhaustive monitoring of the potential risk of exposure from wireless-enabled devices is available, exposures of the young should be As Low As Reasonably Achievable (ALARA). To prevent any potential hazard and damage from the use of wireless devices, some simple rules, such as keeping the device as far away as possible from the eyes, genitals, and breast, should be established. 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 typeexposure_assessment

Effect directionmixed

PopulationHuman anatomical models (young adult male, young adult female, pre-teenager female, male child)

Sample size4

ExposureRF · 3500 MHz

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Using FDTD simulations of a 3.5 GHz E-shaped patch antenna near four human models under varying distances/positions/orientations, the study evaluated whole-body and local (10 g and 1 g) SAR and Bmax. Average SAR values did not exceed recommended limits for all simulated exposure conditions except one, but in some worst-case scenarios for children the maximum absorption ('hot spots') was located in sensitive organs including the eyes, genitals, and breast.

Outcomes measured

Whole-body SAR
Local SAR (10 g)
Local SAR (1 g)
Magnetic field maximum (Bmax)
Localization of maximum SAR ('hot spots') in organs (e.g., eye, genitals, breast)

Limitations

Numerical simulation study (FDTD) rather than measurements in real users
Exposure conditions are modeled scenarios (distances/positions/orientations) and may not represent typical use
No health outcomes assessed; focuses on dosimetry (SAR/Bmax) and hot-spot localization

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "RF",
    "source": "WiMax-enabled tablet or laptop (patch antenna)",
    "frequency_mhz": 3500,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Human anatomical models (young adult male, young adult female, pre-teenager female, male child)",
  "sample_size": 4,
  "outcomes": [
    "Whole-body SAR",
    "Local SAR (10 g)",
    "Local SAR (1 g)",
    "Magnetic field maximum (Bmax)",
    "Localization of maximum SAR ('hot spots') in organs (e.g., eye, genitals, breast)"
  ],
  "main_findings": "Using FDTD simulations of a 3.5 GHz E-shaped patch antenna near four human models under varying distances/positions/orientations, the study evaluated whole-body and local (10 g and 1 g) SAR and Bmax. Average SAR values did not exceed recommended limits for all simulated exposure conditions except one, but in some worst-case scenarios for children the maximum absorption ('hot spots') was located in sensitive organs including the eyes, genitals, and breast.",
  "effect_direction": "mixed",
  "limitations": [
    "Numerical simulation study (FDTD) rather than measurements in real users",
    "Exposure conditions are modeled scenarios (distances/positions/orientations) and may not represent typical use",
    "No health outcomes assessed; focuses on dosimetry (SAR/Bmax) and hot-spot localization"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "radiofrequency",
    "WiMax",
    "IEEE 802.16",
    "4G",
    "LTE",
    "tablet",
    "laptop",
    "patch antenna",
    "E-shaped patch antenna",
    "3.5 GHz",
    "FDTD",
    "specific absorption rate",
    "SAR",
    "whole-body SAR",
    "local SAR",
    "10 g SAR",
    "1 g SAR",
    "magnetic field",
    "Bmax",
    "children",
    "hot spots",
    "eye",
    "genitals",
    "breast",
    "ALARA"
  ],
  "suggested_hubs": []
}

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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.22128
PubMed: Not supplied

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