Effects of Microwave 10 GHz Radiation Exposure in the Skin of Rats: An Insight on Molecular Responses

Abstract

Effects of Microwave 10 GHz Radiation Exposure in the Skin of Rats: An Insight on Molecular Responses Saurabh Verma, Gaurav K Keshri, Santanu Karmakar, Kumar Vyonkesh Mani, Satish Chauhan, Anju Yadav, Manish Sharma, Asheesh Gupta. Effects of Microwave 10 GHz Radiation Exposure in the Skin of Rats: An Insight on Molecular Responses. Radiat Res. 2021 Aug 18. doi: 10.1667/RADE-20-00155.1. Abstract Microwave (MW) radiation poses the risk of potential hazards on human health. The present study investigated the effects of MW 10 GHz exposure for 3 h/day for 30 days at power densities of 5.23 ± 0.25 and 10.01 ± 0.15 mW/cm2 in the skin of rats. The animals exposed to 10 mW/cm2 (corresponded to twice the ICNIRP-2020 occupational reference level of MW exposure for humans) exhibited significant biophysical, biochemical, molecular and histological alterations compared to sham-irradiated animals. Infrared thermography revealed an increase in average skin surface temperature by 1.8°C and standard deviation of 0.3°C after 30 days of 10 mW/cm2 MW exposure compared to the sham-irradiated animals. MW exposure also led to oxidative stress (ROS, 4-HNE, LPO, AOPP), inflammatory responses (NFkB, iNOS/NOS2, COX-2) and metabolic alterations [hexokinase (HK), lactate dehydrogenase (LDH), citrate synthase (CS) and glucose-6-phospahte dehydrogenase (G6PD)] in 10 mW/cm2 irradiated rat skin. A significant alteration in expression of markers associated with cell survival (Akt/PKB) and HSP27/p38MAPK-related stress-response signaling cascade was observed in 10 mW/cm2 irradiated rat skin compared to sham-irradiated rat skin. However, MW-irradiated groups did not show apoptosis, evident by unchanged caspase-3 levels. Histopathological analysis revealed a mild cytoarchitectural alteration in epidermal layer and slight aggregation of leukocytes in 10 mW/cm2 irradiated rat skin. Altogether, the present findings demonstrated that 10 GHz exposure in continuous-wave mode at 10 mW/cm2 (3 h/day, 30 days) led to significant alterations in molecular markers associated with adaptive stress-response in rat skin. Furthermore, systematic scientific studies on more prevalent pulsed-mode of MW-radiation exposure for prolonged duration are warranted. pubmed.ncbi.nlm.nih.gov

AI evidence extraction

Main findings

Rats exposed to 10 GHz at 10 mW/cm2 (3 h/day for 30 days) showed increased skin surface temperature (~1.8°C) and significant changes in oxidative stress, inflammatory, metabolic, and stress-response signaling markers versus sham. Caspase-3 levels were unchanged (no evidence of apoptosis), and histology showed mild epidermal cytoarchitectural alteration with slight leukocyte aggregation at 10 mW/cm2.

Outcomes measured

• Skin surface temperature (infrared thermography)
• Biophysical/biochemical/molecular alterations in skin
• Oxidative stress markers (ROS, 4-HNE, LPO, AOPP)
• Inflammatory markers (NFkB, iNOS/NOS2, COX-2)
• Metabolic enzymes/markers (HK, LDH, CS, G6PD)
• Cell survival/stress signaling markers (Akt/PKB, HSP27/p38MAPK)
• Apoptosis marker (caspase-3)
• Histopathology (epidermal cytoarchitecture, leukocyte aggregation)

Limitations

• Sample size not reported in abstract
• Only rat skin studied; generalizability to humans not addressed in abstract
• Exposure described as continuous-wave; authors note need for studies on pulsed-mode exposure
• Lower power density group (5.23 mW/cm2) results not detailed in abstract

Suggested hubs

• who-icnirp (0.6)
  Abstract explicitly references ICNIRP-2020 occupational reference level.
• occupational-exposure (0.45)
  Exposure level is compared to an occupational reference level.

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        "frequency_mhz": 10000,
        "sar_wkg": null,
        "duration": "3 h/day for 30 days; continuous-wave; power densities 5.23 ± 0.25 and 10.01 ± 0.15 mW/cm2"
    },
    "population": "Rats (skin)",
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    "outcomes": [
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        "Biophysical/biochemical/molecular alterations in skin",
        "Oxidative stress markers (ROS, 4-HNE, LPO, AOPP)",
        "Inflammatory markers (NFkB, iNOS/NOS2, COX-2)",
        "Metabolic enzymes/markers (HK, LDH, CS, G6PD)",
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    "main_findings": "Rats exposed to 10 GHz at 10 mW/cm2 (3 h/day for 30 days) showed increased skin surface temperature (~1.8°C) and significant changes in oxidative stress, inflammatory, metabolic, and stress-response signaling markers versus sham. Caspase-3 levels were unchanged (no evidence of apoptosis), and histology showed mild epidermal cytoarchitectural alteration with slight leukocyte aggregation at 10 mW/cm2.",
    "effect_direction": "harm",
    "limitations": [
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        "Only rat skin studied; generalizability to humans not addressed in abstract",
        "Exposure described as continuous-wave; authors note need for studies on pulsed-mode exposure",
        "Lower power density group (5.23 mW/cm2) results not detailed in abstract"
    ],
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    "peer_reviewed_likely": "yes",
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