RF Safe

No effects of 900 MHz and 1800 MHz electromagnetic field emitted from cellular phone on nocturnal serum melatonin levels in rats.

Toxicology and industrial health · 2005 · No effect · Low evidence

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No effectLow evidencePaper 5177

Thirty rats were assigned to 900 MHz exposure, 1800 MHz exposure, or sham exposure (10 per group). No statistically significant differences in nocturnal serum melatonin concentrations were observed between either exposure group and sham (P > 0.05).

Study snapshot

PublicationToxicology and industrial health · 2005
Study typeanimal
Reported directionNo effect
Evidence ratingLow

Abstract

In this study, the effects of exposure to a 900 MHz and 1800 MHz electromagnetic field (EMF) on serum nocturnal melatonin levels of adult male Sprague-Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were exposed to 900 MHz, 10 of which were exposed to 1800 MHz and 10 of which were sham-exposed (control). The exposures were performed 30 min/day, for five days/week for four weeks to 900 MHz or 1800 MHz EMF Control animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of nocturnal melatonin in the rat serum was measured by using a radioimmunoassay method. There were no statistically significant differences in serum melatonin concentrations between the 900 MHz EMF group and the sham-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 34.97 +/- 5.1 pg/mL in the 900 MHz EMF-exposed group. Also, there were no statistically significant differences in serum melatonin concentrations between the sham-exposed group and the 1800 MHz EMF-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 37.96 +/- 7.4 pg/mL in the exposed group. These results indicate that mobile phones, emitting 900 and 1800 MHz EMF, have no effect on nocturnal serum melatonin levels in rats.

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
PopulationAdult male Sprague-Dawley rats
Sample size30
ExposureRF · 30 min/day, 5 days/week for 4 weeks
Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Thirty rats were assigned to 900 MHz exposure, 1800 MHz exposure, or sham exposure (10 per group). No statistically significant differences in nocturnal serum melatonin concentrations were observed between either exposure group and sham (P > 0.05).

Outcomes measured

  • Nocturnal serum melatonin concentration (radioimmunoassay)

Limitations

  • SAR or exposure intensity not reported in abstract
  • Only adult male rats studied
  • Short exposure duration (4 weeks)
  • Single biomarker outcome (serum nocturnal melatonin) reported
View raw extracted JSON
{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "30 min/day, 5 days/week for 4 weeks"
  },
  "population": "Adult male Sprague-Dawley rats",
  "sample_size": 30,
  "outcomes": [
    "Nocturnal serum melatonin concentration (radioimmunoassay)"
  ],
  "main_findings": "Thirty rats were assigned to 900 MHz exposure, 1800 MHz exposure, or sham exposure (10 per group). No statistically significant differences in nocturnal serum melatonin concentrations were observed between either exposure group and sham (P > 0.05).",
  "effect_direction": "no_effect",
  "limitations": [
    "SAR or exposure intensity not reported in abstract",
    "Only adult male rats studied",
    "Short exposure duration (4 weeks)",
    "Single biomarker outcome (serum nocturnal melatonin) reported"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "900 MHz",
    "1800 MHz",
    "RF-EMF",
    "mobile phone",
    "rats",
    "Sprague-Dawley",
    "melatonin",
    "nocturnal serum",
    "radioimmunoassay",
    "sham-exposed"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones-rf",
      "weight": 0.9,
      "reason": "Study tests 900/1800 MHz EMF emitted from cellular phones in an animal model."
    }
  ]
}
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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: 10.1191/0748233705th212oa
PubMed: 15986574

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