Effects of 900 MHz electromagnetic field on TSH and thyroid hormones in rats.

Toxicology letters · 2005 · Harm · Low evidence

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HarmLow evidencePaper 5180

In rats exposed to 900 MHz EMF, serum TSH and T3/T4 levels were significantly lower than in sham-exposed rats (p<0.01). No statistically significant differences were observed between control and sham-exposed groups (p>0.05).

Study snapshot

PublicationToxicology letters · 2005

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

In this study, the effects of exposure to a 900 megahertz (MHz) electromagnetic field (EMF) on serum thyroid stimulating hormone (TSH) and triiodothronine-thyroxin (T3-T4) hormones levels of adult male Sprague-Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were control (without stress and EMF), 10 of which were exposed to 900 MHz EMF and 10 of which were sham-exposed. The exposures were performed 30 min/day, for 5 days/week for 4 weeks to 900 MHz EMF. Sham-exposed animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of TSH and T3-T4 hormones in the rat serum was measured by using an immunoradiometric assay (IRMA) method for TSH and a radio-immunoassay (RIA) method for T3 and T4 hormones. TSH values and T3-T4 at the 900 MHz EMF group were significantly lower than the sham-exposed group (p<0.01). There were no statistically significant differences in serum TSH values and T3-T4 hormone concentrations between the control and the sham-exposed group (p>0.05). These results indicate that 900 MHz EMF emitted by cellular telephones decrease serum TSH and T3-T4 levels.

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 directionharm

PopulationAdult male Sprague-Dawley rats

Sample size30

ExposureRF · 900 MHz · 30 min/day, 5 days/week for 4 weeks

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Outcomes measured

Serum thyroid stimulating hormone (TSH)
Serum triiodothyronine (T3)
Serum thyroxine (T4)

Limitations

No specific absorption rate (SAR) or exposure intensity reported in the abstract
Only adult male rats studied (generalizability limited)
Short-term exposure period (4 weeks)

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": "mobile phone",
    "frequency_mhz": 900,
    "sar_wkg": null,
    "duration": "30 min/day, 5 days/week for 4 weeks"
  },
  "population": "Adult male Sprague-Dawley rats",
  "sample_size": 30,
  "outcomes": [
    "Serum thyroid stimulating hormone (TSH)",
    "Serum triiodothyronine (T3)",
    "Serum thyroxine (T4)"
  ],
  "main_findings": "In rats exposed to 900 MHz EMF, serum TSH and T3/T4 levels were significantly lower than in sham-exposed rats (p<0.01). No statistically significant differences were observed between control and sham-exposed groups (p>0.05).",
  "effect_direction": "harm",
  "limitations": [
    "No specific absorption rate (SAR) or exposure intensity reported in the abstract",
    "Only adult male rats studied (generalizability limited)",
    "Short-term exposure period (4 weeks)"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "900 MHz",
    "RF-EMF",
    "cellular telephone",
    "rats",
    "Sprague-Dawley",
    "thyroid stimulating hormone",
    "TSH",
    "triiodothyronine",
    "T3",
    "thyroxine",
    "T4",
    "endocrine"
  ],
  "suggested_hubs": [
    {
      "slug": "mobile-phones",
      "weight": 0.9,
      "reason": "Study examines 900 MHz EMF emitted by cellular telephones."
    }
  ]
}

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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: 10.1016/j.toxlet.2005.03.006
PubMed: 15917150

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