Electromagnetic exposure analysis of the subway passenger under the civil communication system

Abstract

Electromagnetic exposure analysis of the subway passenger under the civil communication system radiation Zhou WY, Zhang XY, Lu M. Electromagnetic exposure analysis of the subway passenger under the civil communication system radiation. PLoS One. 2024 Mar 11;19(3):e0300049. doi: 10.1371/journal.pone.0300049. Abstract In order to assess the electromagnetic exposure safety of passengers under the civil communication system of the subway, the radio-frequency (RF) electromagnetic environment of subway carriage is established by using COMSOL Multiphysics software, it includes a 1-1/4 " leaky coaxial cable (LCX1) and a 1-5/8" leaky coaxial cable (LCX2), which are designed to be the exposure sources, and twelve passengers at different position. The electromagnetic environment model has been verified through field measurement. The exposure dose distribution of twelve passengers is compared and analyzed, when LCX1 and LCX2 works respectively. The simulated results show that, to compare with LCX2, the electromagnetic dose absorbed by the passengers is reduced by 9.19% and 22.50% at 2100 MHz and 2600 MHz respectively. The specific absorption rate (SAR) of passengers obtains the maximum value of 1.91×10−4 W/Kg and the temperature rise to 0.214 K when the LCX1 works at 3400 MHz. By comparing with the public exposure limitation of the International Commission of Non-Ionizing Radiation Protection (ICNIRP), it demonstrates the electromagnetic exposure safety of the passengers under the civil communication system. More importantly, the proposed LCX1 not only could add the 5G signal cover but also lower the SAR absorbed by the passengers, which indicates that the public electromagnetic exposure dose could be reduced by adjusting the radiation performances of exposure source, which provide a new way for electromagnetic protecting. Open access paper: journals.plos.org

AI evidence extraction

Main findings

A COMSOL-based subway carriage RF exposure model (with LCX1 and LCX2 as sources) was verified through field measurement. Simulations indicated passenger absorbed electromagnetic dose was lower with LCX1 than LCX2 by 9.19% at 2100 MHz and 22.50% at 2600 MHz. The maximum reported passenger SAR was 1.91×10−4 W/kg with a temperature rise of 0.214 K when LCX1 operated at 3400 MHz; the authors report exposures were within ICNIRP public limits.

Outcomes measured

• RF electromagnetic environment in subway carriage (modeled and field-verified)
• Passenger exposure dose distribution (simulated)
• Specific absorption rate (SAR)
• Temperature rise
• Comparison to ICNIRP public exposure limits

Limitations

• Simulation/modeling study; real-world passenger exposures are not directly measured for all scenarios
• Only twelve passenger positions were modeled
• Exposure sources limited to two leaky coaxial cable designs (LCX1, LCX2)
• Details of field measurement methods and measurement results are not provided in the abstract

Suggested hubs

• who-icnirp (0.78)
  Abstract explicitly compares results with ICNIRP public exposure limits.
• 5g-policy (0.55)
  Mentions adding 5G signal cover and evaluates exposure at 3400 MHz.
• occupational-exposure (0.2)

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    "exposure": {
        "band": "RF",
        "source": "subway civil communication system using leaky coaxial cable (LCX)",
        "frequency_mhz": null,
        "sar_wkg": 0.00019100000000000000766227359338955693601747043430805206298828125,
        "duration": null
    },
    "population": "Subway passengers (modeled; 12 passengers at different positions in a subway carriage)",
    "sample_size": 12,
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        "Passenger exposure dose distribution (simulated)",
        "Specific absorption rate (SAR)",
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        "Comparison to ICNIRP public exposure limits"
    ],
    "main_findings": "A COMSOL-based subway carriage RF exposure model (with LCX1 and LCX2 as sources) was verified through field measurement. Simulations indicated passenger absorbed electromagnetic dose was lower with LCX1 than LCX2 by 9.19% at 2100 MHz and 22.50% at 2600 MHz. The maximum reported passenger SAR was 1.91×10−4 W/kg with a temperature rise of 0.214 K when LCX1 operated at 3400 MHz; the authors report exposures were within ICNIRP public limits.",
    "effect_direction": "no_effect",
    "limitations": [
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        "Only twelve passenger positions were modeled",
        "Exposure sources limited to two leaky coaxial cable designs (LCX1, LCX2)",
        "Details of field measurement methods and measurement results are not provided in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
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        "RF exposure",
        "civil communication system",
        "leaky coaxial cable",
        "LCX",
        "COMSOL Multiphysics",
        "SAR",
        "temperature rise",
        "ICNIRP",
        "2100 MHz",
        "2600 MHz",
        "3400 MHz",
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