[Exposure to electromagnetic fields and risk of central nervous system diseases among employees at Danish electric companies].

Ugeskrift for laeger · 2001 · Mixed · Low evidence

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MixedLow evidencePaper 3914

Study snapshot

PublicationUgeskrift for laeger · 2001

Study typecohort

Reported directionMixed

Evidence ratingLow

Abstract

INTRODUCTION: Occupational exposure to electromagnetic fields has been associated with neurological diseases, such as amyotrophic lateral sclerosis, senile dementia, Parkinson's disease and Alzheimer's disease. MATERIAL AND METHOD: I studied the incidence of disease in the central nervous system in 30,631 persons employed at Danish electric companies between 1900 and 1993. I linked the cohort to the nationwide, population-based Danish National Register of Patients and compared the number of cases of these diseases found between 1978 and 1993 with the corresponding rates in the general population. In addition, I fit the data on utility workers to a multiplicative Poisson regression model in relation to estimated levels of exposure to 50 Hz electromagnetic fields. RESULTS: Overall, there was an increase in the risk of senile dementia and motor neuron diseases combined. The incidences of Parkinson's disease, Alzheimer's disease and other diseases of the central nervous system were essentially unrelated to exposure to electromagnetic fields. A decreased risk of epilepsy compared with the general population probably reflects a healthy worker effect; I observed an increased risk of epilepsy based on internal comparisons. DISCUSSION: The increased risk of senile dementia and motor neuron diseases may be associated with above average levels of exposure to electromagnetic fields.

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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 typecohort

Effect directionmixed

PopulationEmployees at Danish electric companies

Sample size30631

ExposureELF · 0.05 MHz · employment in Danish electric companies (cohort employed 1900–1993; outcomes assessed 1978–1993)

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In a cohort of 30,631 Danish electric company employees, there was an overall increase in risk of senile dementia and motor neuron diseases combined. Parkinson's disease, Alzheimer's disease, and other CNS diseases were reported as essentially unrelated to EMF exposure. Epilepsy risk was decreased versus the general population (attributed to healthy worker effect), but increased in internal comparisons; the discussion notes the increased risk of senile dementia and motor neuron diseases may be associated with above-average 50 Hz EMF exposure.

Outcomes measured

senile dementia
motor neuron diseases
Parkinson's disease
Alzheimer's disease
other central nervous system diseases
epilepsy

Limitations

Exposure was based on estimated levels of 50 Hz electromagnetic fields (details not provided in abstract).
Comparisons to the general population may be affected by healthy worker effect (explicitly noted for epilepsy).
Outcome ascertainment window (1978–1993) may not capture earlier cases for a cohort employed as early as 1900 (latency/left truncation not discussed in abstract).

View raw extracted JSON

{
  "study_type": "cohort",
  "exposure": {
    "band": "ELF",
    "source": "occupational",
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "employment in Danish electric companies (cohort employed 1900–1993; outcomes assessed 1978–1993)"
  },
  "population": "Employees at Danish electric companies",
  "sample_size": 30631,
  "outcomes": [
    "senile dementia",
    "motor neuron diseases",
    "Parkinson's disease",
    "Alzheimer's disease",
    "other central nervous system diseases",
    "epilepsy"
  ],
  "main_findings": "In a cohort of 30,631 Danish electric company employees, there was an overall increase in risk of senile dementia and motor neuron diseases combined. Parkinson's disease, Alzheimer's disease, and other CNS diseases were reported as essentially unrelated to EMF exposure. Epilepsy risk was decreased versus the general population (attributed to healthy worker effect), but increased in internal comparisons; the discussion notes the increased risk of senile dementia and motor neuron diseases may be associated with above-average 50 Hz EMF exposure.",
  "effect_direction": "mixed",
  "limitations": [
    "Exposure was based on estimated levels of 50 Hz electromagnetic fields (details not provided in abstract).",
    "Comparisons to the general population may be affected by healthy worker effect (explicitly noted for epilepsy).",
    "Outcome ascertainment window (1978–1993) may not capture earlier cases for a cohort employed as early as 1900 (latency/left truncation not discussed in abstract)."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "occupational exposure",
    "electric utility workers",
    "ELF",
    "50 Hz",
    "electromagnetic fields",
    "central nervous system diseases",
    "senile dementia",
    "motor neuron disease",
    "ALS",
    "Parkinson's disease",
    "Alzheimer's disease",
    "epilepsy",
    "Poisson regression",
    "Danish National Register of Patients"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.95,
      "reason": "Cohort of electric company employees with estimated 50 Hz EMF exposure."
    }
  ]
}

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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: Not supplied
PubMed: 11810798

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