Biological effects of high-frequency electromagnetic fields on Salmonella typhimurium and Drosophila melanogaster.

Abstract

Salmonella typhimurium and Drosophila melanogaster were exposed to continuous wave (CW) 2.45-GHz electromagnetic radiation, pulsed 3.10-GHz electromagnetic radiation, CW 27.12-MHz magnetic fields, or CW 27.12-MHz electric fields (only Drosophila). The temperatures of the treated sample and the nonexposed control sample were kept constant. The temperature difference between exposed and control samples was less than +/- 0.3 degrees C. Ames' assays were made on bacteria that had been exposed to microwaves (SAR 60-130 W/kg) or RF fields (SAR up to 20 W/kg) when growing exponentially in nutrient broth. Survival and number of induced revertants to histidine prototrophy were determined by common plating techniques on rich and minimal agar plates. The Drosophila test consisted of a sensitive somatic system where the mutagenicity was measured by means of mutations in a gene-controlling eye pigmentation. In none of these test systems did microwave or radiofrequency fields induce an elevated mutation frequency. However, a significantly higher concentration of cells was found in the bacterial cultures exposed to the 27-MHz magnetic field or 2.45-GHz CW and 3.10-GHz pulsed microwave radiation.

AI evidence extraction

Main findings

Across the bacterial Ames assays and a Drosophila somatic mutation test, microwave or radiofrequency field exposures did not induce an elevated mutation frequency. A significantly higher concentration of cells was observed in bacterial cultures exposed to a 27.12-MHz magnetic field and to 2.45-GHz CW and 3.10-GHz pulsed microwave radiation.

Outcomes measured

• Mutation frequency (Ames assay revertants to histidine prototrophy)
• Bacterial survival
• Somatic mutation in Drosophila eye pigmentation gene
• Bacterial cell concentration (growth)

Limitations

• Sample size not reported in abstract
• Exposure duration not reported in abstract
• Frequency and SAR values are reported for some conditions but not all; exposure characterization is incomplete in the abstract
• Findings are limited to bacterial and insect test systems (no human/clinical outcomes)

{
    "study_type": "other",
    "exposure": {
        "band": "RF",
        "source": null,
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Salmonella typhimurium and Drosophila melanogaster",
    "sample_size": null,
    "outcomes": [
        "Mutation frequency (Ames assay revertants to histidine prototrophy)",
        "Bacterial survival",
        "Somatic mutation in Drosophila eye pigmentation gene",
        "Bacterial cell concentration (growth)"
    ],
    "main_findings": "Across the bacterial Ames assays and a Drosophila somatic mutation test, microwave or radiofrequency field exposures did not induce an elevated mutation frequency. A significantly higher concentration of cells was observed in bacterial cultures exposed to a 27.12-MHz magnetic field and to 2.45-GHz CW and 3.10-GHz pulsed microwave radiation.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in abstract",
        "Exposure duration not reported in abstract",
        "Frequency and SAR values are reported for some conditions but not all; exposure characterization is incomplete in the abstract",
        "Findings are limited to bacterial and insect test systems (no human/clinical outcomes)"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "2.45 GHz",
        "3.10 GHz",
        "27.12 MHz",
        "microwave radiation",
        "radiofrequency fields",
        "continuous wave",
        "pulsed",
        "SAR",
        "Ames assay",
        "mutagenicity",
        "Salmonella typhimurium",
        "Drosophila melanogaster",
        "somatic mutation",
        "eye pigmentation",
        "cell concentration",
        "growth"
    ],
    "suggested_hubs": []
}

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