Stress-related endocrinological and psychopathological effects of short- and long-term 50Hz electromagnetic field exposure in rats.

Brain research bulletin · 2010 · Harm · Low evidence

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HarmLow evidencePaper 4410

Study snapshot

PublicationBrain research bulletin · 2010

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

It is believed that different electromagnetic fields do have beneficial and harmful biological effects. The aim of the present work was to study the long-term consequences of 50 Hz electromagnetic field (ELF-EMF) exposure with special focus on the development of chronic stress and stress-induced psychopathology. Adult male Sprague-Dawley rats were exposed to ELF-EMF (50 Hz, 0.5 mT) for 5 days, 8h daily (short) or for 4-6 weeks, 24h daily (long). Anxiety was studied in elevated plus maze test, whereas depression-like behavior of the long-treated group was examined in the forced swim test. Some days after behavioral examination, the animals were decapitated among resting conditions and organ weights, blood hormone levels as well as proopiomelanocortin mRNA level from the anterior lobe of the pituitary gland were measured. Both treatments were ineffective on somatic parameters, namely none of the changes characteristic to chronic stress (body weight reduction, thymus involution and adrenal gland hypertrophy) were present. An enhanced blood glucose level was found after prolonged ELF-EMF exposure (p=0.013). The hormonal stress reaction was similar in control and short-term exposed rats, but significant proopiomelanocortin elevation (p<0.000) and depressive-like behavior (enhanced floating time; p=0.006) were found following long-term ELF-EMF exposure. Taken together, long and continuous exposure to relatively high intensity electromagnetic field may count as a mild stress situation and could be a factor in the development of depressive state or metabolic disturbances. Although we should stress that the average intensity of the human exposure is normally much smaller than in the present experiment.

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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 sizeNot supplied

ExposureELF · 0.05 MHz · Short: 5 days, 8 h/day; Long: 4–6 weeks, 24 h/day

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Short- and long-term 50 Hz, 0.5 mT ELF-EMF exposure did not produce somatic changes characteristic of chronic stress (no body weight reduction, thymus involution, or adrenal hypertrophy). After prolonged exposure, blood glucose was increased (p=0.013), pituitary proopiomelanocortin mRNA was elevated (p<0.000), and depressive-like behavior (increased floating time) was observed (p=0.006); hormonal stress reaction was similar in controls and short-term exposed rats.

Outcomes measured

Anxiety (elevated plus maze)
Depression-like behavior (forced swim test; floating time)
Somatic stress parameters (body weight, thymus, adrenal gland weights)
Blood glucose level
Blood hormone levels
Pituitary proopiomelanocortin (POMC) mRNA (anterior lobe)

Limitations

Sample size not reported in abstract
Animal study; generalizability to humans is limited
Exposure intensity noted as higher than typical human exposure
Details of exposure setup and specific hormone results not provided in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "Short: 5 days, 8 h/day; Long: 4–6 weeks, 24 h/day"
  },
  "population": "Adult male Sprague-Dawley rats",
  "sample_size": null,
  "outcomes": [
    "Anxiety (elevated plus maze)",
    "Depression-like behavior (forced swim test; floating time)",
    "Somatic stress parameters (body weight, thymus, adrenal gland weights)",
    "Blood glucose level",
    "Blood hormone levels",
    "Pituitary proopiomelanocortin (POMC) mRNA (anterior lobe)"
  ],
  "main_findings": "Short- and long-term 50 Hz, 0.5 mT ELF-EMF exposure did not produce somatic changes characteristic of chronic stress (no body weight reduction, thymus involution, or adrenal hypertrophy). After prolonged exposure, blood glucose was increased (p=0.013), pituitary proopiomelanocortin mRNA was elevated (p<0.000), and depressive-like behavior (increased floating time) was observed (p=0.006); hormonal stress reaction was similar in controls and short-term exposed rats.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in abstract",
    "Animal study; generalizability to humans is limited",
    "Exposure intensity noted as higher than typical human exposure",
    "Details of exposure setup and specific hormone results not provided in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF-EMF",
    "50 Hz",
    "0.5 mT",
    "rats",
    "chronic stress",
    "depression-like behavior",
    "forced swim test",
    "elevated plus maze",
    "blood glucose",
    "proopiomelanocortin",
    "pituitary"
  ],
  "suggested_hubs": [
    {
      "slug": "elf-emf",
      "weight": 0.9,
      "reason": "Animal experiment with 50 Hz (ELF) magnetic field exposure and stress-related outcomes."
    }
  ]
}

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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.brainresbull.2009.10.015
PubMed: 19883742

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