Teratogenic, biochemical, and histological studies with mice prenatally exposed to 2.45-GHz microwave radiation.

Abstract

Pregnant CD-1 mice were exposed to 2.45-GHz continuous wave microwave radiation at an incident power density of 30 mW/cm2. The local specific absorption rate near the uterine area (deep colonic location), as determined from time-temperature profiles measured with a Vitek thermistor probe, was 40.2 mW/g. Groups of mice were exposed 8 hr per day through Days 1-6 or 6-15 of pregnancy. Other groups of animals were exposed to an elevated ambient temperature of 31 degrees C which increased the colonic temperature 2.3 degrees C, the same as that produced by the microwaves. Sham-irradiated groups of animals were treated exactly the same as the microwave-exposed animals. For the two conditions, temperature exposed and sham exposed, two groups of animals were used. One group was handled in the same manner as the microwave-irradiated group and the other group was not handled so as to evaluate the effects of stressing the animals by handling. Eleven groups of animals were used in the complete study: five groups for gestational Days 1-6, five groups for gestational Days 6-15, and one group of cage control animals. On Day 18 of gestation the dams of all experimental groups were sacrificed and their reproductive status was determined. The fetuses were examined for visceral and skeletal alterations. Brain cholinesterase activity and histology were evaluated in the groups exposed on Days 6-15. The results show that microwave radiation increases embryo lethality at the early stages of gestation (exposure Days 1-6). Fetal toxicity and teratogenicity were not significantly increased by exposure to microwaves on either Days 1-6 or 6-15 of gestation. Cholinesterase activity and histology of the brain of 18-day-old fetuses were not adversely affected.

AI evidence extraction

Main findings

Microwave exposure (2.45 GHz; incident power density 30 mW/cm2; local SAR near uterine area 40.2 mW/g) increased embryo lethality when exposure occurred during early gestation (Days 1–6). Fetal toxicity and teratogenicity were not significantly increased for exposures during Days 1–6 or 6–15, and fetal brain cholinesterase activity and histology (assessed for Days 6–15 exposure groups) were not adversely affected.

Outcomes measured

• Embryo lethality
• Fetal toxicity
• Teratogenicity (visceral and skeletal alterations)
• Fetal brain cholinesterase activity
• Fetal brain histology
• Maternal/colonic temperature change

Limitations

• Sample size not reported in the abstract.
• Findings are from an animal model (mice), limiting direct generalization to humans.
• Exposure metric reported as local SAR near uterine area (deep colonic location); whole-body or fetal SAR not specified in the abstract.
• Thermal confounding addressed via elevated ambient temperature groups, but detailed comparative results for temperature vs microwave groups are not provided in the abstract.

Suggested hubs

• animal-studies (0.9)
  Prenatal microwave exposure experiment in mice with developmental outcomes.

{
    "study_type": "animal",
    "exposure": {
        "band": "microwave",
        "source": null,
        "frequency_mhz": 2450,
        "sar_wkg": 40.2000000000000028421709430404007434844970703125,
        "duration": "8 hr/day; gestational Days 1–6 or 6–15"
    },
    "population": "Pregnant CD-1 mice and their fetuses",
    "sample_size": null,
    "outcomes": [
        "Embryo lethality",
        "Fetal toxicity",
        "Teratogenicity (visceral and skeletal alterations)",
        "Fetal brain cholinesterase activity",
        "Fetal brain histology",
        "Maternal/colonic temperature change"
    ],
    "main_findings": "Microwave exposure (2.45 GHz; incident power density 30 mW/cm2; local SAR near uterine area 40.2 mW/g) increased embryo lethality when exposure occurred during early gestation (Days 1–6). Fetal toxicity and teratogenicity were not significantly increased for exposures during Days 1–6 or 6–15, and fetal brain cholinesterase activity and histology (assessed for Days 6–15 exposure groups) were not adversely affected.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in the abstract.",
        "Findings are from an animal model (mice), limiting direct generalization to humans.",
        "Exposure metric reported as local SAR near uterine area (deep colonic location); whole-body or fetal SAR not specified in the abstract.",
        "Thermal confounding addressed via elevated ambient temperature groups, but detailed comparative results for temperature vs microwave groups are not provided in the abstract."
    ],
    "evidence_strength": "low",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "mouse",
        "prenatal exposure",
        "pregnancy",
        "2.45 GHz",
        "microwave radiation",
        "continuous wave",
        "power density",
        "SAR",
        "embryo lethality",
        "teratogenicity",
        "fetal brain",
        "cholinesterase",
        "histology",
        "thermal effects"
    ],
    "suggested_hubs": [
        {
            "slug": "animal-studies",
            "weight": 0.90000000000000002220446049250313080847263336181640625,
            "reason": "Prenatal microwave exposure experiment in mice with developmental outcomes."
        }
    ]
}

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