1.7 GHz LTE radiofrequency EMF with stable power monitoring and efficient thermal control has no

Abstract

1.7 GHz LTE radiofrequency EMF with stable power monitoring and efficient thermal control has no effect on the proliferation of various human cell types My note: The study employed a Western blot analysis which is less likely to detect DNA damage than a comet assay. Goh J, Suh D, Park G, Jeon S, Lee Y, Kim N, Song K. 1.7 GHz long-term evolution radiofrequency electromagnetic field with stable power monitoring and efficient thermal control has no effect on the proliferation of various human cell types. PLoS One. 2024 May 7;19(5):e0302936. doi: 10.1371/journal.pone.0302936. Abstract Long-term evolution (LTE) radiofrequency electromagnetic field (RF-EMF) is widely used in communication technologies. Thus, the influence of RF-EMF on biological systems is a major public concern and its physiological effects remain controversial. In our previous study, we showed that continuous exposure of various human cell types to 1.7 GHz LTE RF-EMF at a specific absorption rate (SAR) of 2 W/Kg for 72 h can induce cellular senescence. To understand the precise cellular effects of LTE RF-EMF, we elaborated the 1.7 GHz RF-EMF cell exposure system used in the previous study by replacing the RF signal generator and developing a software-based feedback system to improve the exposure power stability. This refinement of the 1.7 GHz LTE RF-EMF generator facilitated the automatic regulation of RF-EMF exposure, maintaining target power levels within a 3% range and a constant temperature even during the 72-h-exposure period. With the improved experimental setup, we examined the effect of continuous exposure to 1.7 GHz LTE RF-EMF at up to SAR of 8 W/Kg in human adipose tissue-derived stem cells (ASCs), Huh7, HeLa, and rat B103 cells. Surprisingly, the proliferation of all cell types, which displayed different growth rates, did not change significantly compared with that of the unexposed controls. Also, neither DNA damage nor cell cycle perturbation was observed in the 1.7 GHz LTE RF-EMF-exposed cells. However, when the thermal control system was turned off and the subsequent temperature increase induced by the RF-EMF was not controlled during continuous exposure to SAR of 8 W/Kg LTE RF-EMF, cellular proliferation increased by 35.2% at the maximum. These observations strongly suggest that the cellular effects attributed to 1.7 GHz LTE RF-EMF exposure are primarily due to the induced thermal changes rather than the RF-EMF exposure itself. Conclusion To understand the precise cellular effect of 1.7 GHz LTE RF-EMF, we developed an RF-EMF cell exposure system with an improved RF signal generator and control software. With a refined RF-EMF exposure system, we could maintain a consistent target power during the 72-h-exposure period with minimal thermal effects. With this refined experimental setup, exposure to 1.7 GHz LTE RF-EMF at the SAR ranging from 0.4 W/Kg to 8 W/Kg neither affects the proliferation of various human cells with different growth rates nor induces DNA damage and cell cycle perturbation. Before upgrading the exposure system, we observed that the exposure of human cells to 1.7 GHz RF-EMF increased or decreased cell proliferation, depending on the SAR values. In addition, we verified that exposure to 1.7 GHz RF-EMF with this refined system affected cell proliferation when heat was not properly controlled. Altogether, these results suggest that exposure to 1.7 GHz LTE RF-EMF does not directly influence cell proliferation and that the physiological changes induced by RF-EMF might be associated with thermal effects. Open access paper: journals.plos.org

AI evidence extraction

Main findings

Using an improved 1.7 GHz LTE RF-EMF exposure system with software feedback and thermal control, continuous exposure for 72 h at SAR up to 8 W/kg did not significantly change proliferation in human adipose-derived stem cells, Huh7, HeLa, or rat B103 cells versus unexposed controls, and no DNA damage or cell-cycle perturbation was observed. When thermal control was turned off during SAR 8 W/kg exposure, proliferation increased (up to 35.2%), suggesting observed effects were attributable to heating rather than RF-EMF itself.

Outcomes measured

• Cell proliferation
• DNA damage
• Cell cycle perturbation
• Cellular senescence (referenced from previous study)
• Temperature/thermal effects during exposure
• Exposure power stability (within 3%)

Limitations

• Sample size not reported in provided abstract/metadata
• DNA damage assay methods not specified in the abstract (only states no DNA damage observed)
• In vitro cell models; generalizability to in vivo/human health outcomes not addressed in abstract
• Prior findings of senescence at SAR 2 W/kg for 72 h are referenced but not detailed here

Suggested hubs

• 5g-policy (0.1)
  Study concerns LTE (4G) RF exposure systems; only loosely related to newer cellular network policy discussions.

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    "exposure": {
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        "source": "LTE",
        "frequency_mhz": 1700,
        "sar_wkg": 8,
        "duration": "72 h"
    },
    "population": null,
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    "outcomes": [
        "Cell proliferation",
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        "Cellular senescence (referenced from previous study)",
        "Temperature/thermal effects during exposure",
        "Exposure power stability (within 3%)"
    ],
    "main_findings": "Using an improved 1.7 GHz LTE RF-EMF exposure system with software feedback and thermal control, continuous exposure for 72 h at SAR up to 8 W/kg did not significantly change proliferation in human adipose-derived stem cells, Huh7, HeLa, or rat B103 cells versus unexposed controls, and no DNA damage or cell-cycle perturbation was observed. When thermal control was turned off during SAR 8 W/kg exposure, proliferation increased (up to 35.2%), suggesting observed effects were attributable to heating rather than RF-EMF itself.",
    "effect_direction": "no_effect",
    "limitations": [
        "Sample size not reported in provided abstract/metadata",
        "DNA damage assay methods not specified in the abstract (only states no DNA damage observed)",
        "In vitro cell models; generalizability to in vivo/human health outcomes not addressed in abstract",
        "Prior findings of senescence at SAR 2 W/kg for 72 h are referenced but not detailed here"
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "LTE",
        "RF-EMF",
        "1.7 GHz",
        "1700 MHz",
        "SAR",
        "thermal control",
        "power stability",
        "cell proliferation",
        "DNA damage",
        "cell cycle",
        "in vitro",
        "HeLa",
        "Huh7",
        "adipose-derived stem cells",
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    ],
    "suggested_hubs": [
        {
            "slug": "5g-policy",
            "weight": 0.1000000000000000055511151231257827021181583404541015625,
            "reason": "Study concerns LTE (4G) RF exposure systems; only loosely related to newer cellular network policy discussions."
        }
    ]
}

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