Electromagnetic Exposure from RF Antennas on Subway Station Attendant: A Thermal Analysis.

Abstract

With the rapid development of wireless communication systems, the electromagnetic environment in subway stations has become increasingly complex, raising concerns about the long-term safety of station attendants who are chronically exposed to radiofrequency (RF) fields. At present, multiphysics analyses specifically addressing RF antenna exposure scenarios for subway attendants remain limited. To assess occupational electromagnetic exposure risks, this paper establishes a comprehensive electromagnetic-thermal coupling simulation model incorporating RF antennas, station-platform structures, and a realistic human model with organs including the brain, heart, and liver. Using the finite-element software COMSOL Multiphysics (v.6.3), numerical simulations are performed to calculate the specific absorption rate (SAR) in the trunk and major organs of the subway station attendant at RF antennas frequencies of 900 MHz, 2600 MHz, and 3500 MHz, as well as the temperature rise distribution of the human trunk and important tissues and organs under different initial temperatures of the environment. The results show that among the three frequencies, the maximum SAR of 5.55 × 10-4 W/kg occurs in the trunk at 3500 MHz. Tissue temperatures reach thermal steady state after 30 min of exposure, with the maximum temperature rises occurring in the brain at an ambient temperature of 18 °C and an operating frequency of 900 MHz, reaching 0.2123 °C. Across all simulated scenarios, both SAR values and temperature rises remain significantly below the occupational exposure limits established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These findings indicate that RF radiation generated by antennas in the subway station environment poses low health risks to female station attendants of similar physical characteristics to the Ella model. This study provides a scientific reference for the occupational RF protection of subway personnel and contributes data for the development of electromagnetic exposure standards in rail transit systems.

AI evidence extraction

Main findings

COMSOL multiphysics electromagnetic-thermal coupling simulations at 900, 2600, and 3500 MHz found a maximum SAR of 5.55 × 10-4 W/kg in the trunk at 3500 MHz. Tissue temperatures reached thermal steady state after 30 min; the maximum temperature rise was 0.2123 °C in the brain at 18 °C ambient temperature and 900 MHz. Across simulated scenarios, SAR and temperature rises were reported as significantly below ICNIRP occupational exposure limits.

Outcomes measured

• Specific absorption rate (SAR) in trunk and major organs
• Temperature rise distribution in trunk and tissues/organs
• Comparison to ICNIRP occupational exposure limits

Limitations

• Simulation study (numerical modeling) rather than measurements in real subway stations
• Results pertain to a specific female human model ('Ella') and may not generalize to other body types/conditions
• Exposure scenario details (e.g., antenna power, distance, duty cycle) not provided in the abstract

Suggested hubs

• occupational-exposure (0.9)
  Assesses chronic/occupational RF exposure risks for subway station attendants.
• who-icnirp (0.7)
  Findings are compared against ICNIRP occupational exposure limits.

{
    "study_type": "engineering",
    "exposure": {
        "band": "RF",
        "source": "RF antennas (subway station environment)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "30 min (thermal steady state reported after 30 min)"
    },
    "population": "Subway station attendant (female human model; organs include brain, heart, liver; 'Ella model')",
    "sample_size": null,
    "outcomes": [
        "Specific absorption rate (SAR) in trunk and major organs",
        "Temperature rise distribution in trunk and tissues/organs",
        "Comparison to ICNIRP occupational exposure limits"
    ],
    "main_findings": "COMSOL multiphysics electromagnetic-thermal coupling simulations at 900, 2600, and 3500 MHz found a maximum SAR of 5.55 × 10-4 W/kg in the trunk at 3500 MHz. Tissue temperatures reached thermal steady state after 30 min; the maximum temperature rise was 0.2123 °C in the brain at 18 °C ambient temperature and 900 MHz. Across simulated scenarios, SAR and temperature rises were reported as significantly below ICNIRP occupational exposure limits.",
    "effect_direction": "no_effect",
    "limitations": [
        "Simulation study (numerical modeling) rather than measurements in real subway stations",
        "Results pertain to a specific female human model ('Ella') and may not generalize to other body types/conditions",
        "Exposure scenario details (e.g., antenna power, distance, duty cycle) not provided in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "subway station",
        "occupational exposure",
        "RF antennas",
        "COMSOL Multiphysics",
        "finite-element simulation",
        "electromagnetic-thermal coupling",
        "SAR",
        "temperature rise",
        "ICNIRP",
        "900 MHz",
        "2600 MHz",
        "3500 MHz"
    ],
    "suggested_hubs": [
        {
            "slug": "occupational-exposure",
            "weight": 0.90000000000000002220446049250313080847263336181640625,
            "reason": "Assesses chronic/occupational RF exposure risks for subway station attendants."
        },
        {
            "slug": "who-icnirp",
            "weight": 0.6999999999999999555910790149937383830547332763671875,
            "reason": "Findings are compared against ICNIRP occupational exposure limits."
        }
    ]
}

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