RF Safe

Effects of exposure of the ear to GSM microwaves: in vivo and in vitro experimental studies.

International journal of audiology · 2004 · No effect · Low evidence

← Research stream
No effectLow evidencePaper 6408

Repeated-measures ANOVA showed no differences in DPOAE amplitudes or ABR thresholds between exposed and non-exposed ears and between sham-exposed and exposed groups. Acute pre/post 1-hour exposure testing showed no statistically significant ABR threshold chan…

Study snapshot

PublicationInternational journal of audiology · 2004
Study typeanimal
Reported directionNo effect
Evidence ratingLow

Abstract

The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h/day, 5 days/week, for 2 months, to GSM microwaves (900 MHz. GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W/kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4W/kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n=15) were isolated and placed in culture. For each animal, one OC was exposed for 24-48 h to 1 W/kg GSM microwaves, and the other was sham-exposed. After 2-3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal
Effect directionno_effect
PopulationGuinea pigs (in vivo) and newborn rats (in vitro; organs of Corti in culture)
Sample sizeNot supplied
ExposureRF · 900 MHz · In vivo: 1 h/day, 5 days/week, for 2 months; acute: single 1-h exposure pre/post testing; In vitro: 24–48 h exposure (1 W/kg)
Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Repeated-measures ANOVA showed no differences in DPOAE amplitudes or ABR thresholds between exposed and non-exposed ears and between sham-exposed and exposed groups. Acute pre/post 1-hour exposure testing showed no statistically significant ABR threshold change. In vitro, exposed and sham-exposed organs of Corti appeared normal under light microscopy.

Outcomes measured

  • Distortion-product otoacoustic emissions (DPOAEs)
  • Auditory brainstem response (ABR) thresholds
  • Light microscopy appearance of organs of Corti in culture
View raw extracted JSON
{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "In vivo: 1 h/day, 5 days/week, for 2 months; acute: single 1-h exposure pre/post testing; In vitro: 24–48 h exposure (1 W/kg)"
  },
  "population": "Guinea pigs (in vivo) and newborn rats (in vitro; organs of Corti in culture)",
  "sample_size": null,
  "outcomes": [
    "Distortion-product otoacoustic emissions (DPOAEs)",
    "Auditory brainstem response (ABR) thresholds",
    "Light microscopy appearance of organs of Corti in culture"
  ],
  "main_findings": "Repeated-measures ANOVA showed no differences in DPOAE amplitudes or ABR thresholds between exposed and non-exposed ears and between sham-exposed and exposed groups. Acute pre/post 1-hour exposure testing showed no statistically significant ABR threshold change. In vitro, exposed and sham-exposed organs of Corti appeared normal under light microscopy.",
  "effect_direction": "no_effect",
  "limitations": [],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "GSM",
    "mobile phone",
    "microwaves",
    "RF exposure",
    "900 MHz",
    "specific absorption rate",
    "SAR",
    "guinea pig",
    "rat",
    "ear",
    "inner ear",
    "auditory pathways",
    "DPOAE",
    "ABR",
    "organ of Corti"
  ],
  "suggested_hubs": []
}
AI can be wrong. Always verify against the paper.

AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1080/14992020400050069
PubMed: 15726845

Read the original paper →

Related papers

← Back to the Research Library