RF Safe

Magnetic fields of transmission lines and depression.

American journal of epidemiology · 1997 · Mixed · Low evidence

← Research stream
MixedLow evidencePaper 4155

Adjusted mean Beck Depression Inventory scores did not differ by exposure to overhead 110- to 400-kV power lines (distance and calculated annual average magnetic fields). The risk of severe depression was increased 4.7-fold (95% CI 1.70–13.3) among subjects l…

Study snapshot

PublicationAmerican journal of epidemiology · 1997
Study typecohort
Reported directionMixed
Evidence ratingLow

Abstract

Electromagnetic fields have been suggested to contribute to the risk of depression by causing pineal dysfunction. Some epidemiologic studies have supported this possibility but have generally reported crude methods of exposure assessment and nonsystematic evaluation of depression. Using two available nationwide data sets, the authors identified from the Finnish Twin Cohort Study 12,063 persons who had answered the 21-item Beck Depression Inventory of self-rated depressive symptoms in 1990. The personal 20-year histories of exposure (i.e., distance and calculated annual average magnetic fields) before 1990 to overhead 110- to 400-kv power lines were obtained from the Finnish Transmission Line Cohort Study. The adjusted mean Beck Depression Inventory scores did not differ by exposure, providing some assurance that proximity to high-voltage transmission lines is not associated with changes within the common range of depressive symptoms. However, the risk of severe depression was increased 4.7-fold (95% confidence interval 1.70-13.3) among subjects living within 100 m of a high-voltage power line. This finding was based on small numbers. The authors recommend that attempts be made to strive for a better understanding of the exposure characteristics in relation to the onset and course of depression.

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 typecohort
Effect directionmixed
PopulationParticipants from the Finnish Twin Cohort Study who completed the Beck Depression Inventory in 1990
Sample size12063
ExposureELF · 20-year exposure histories before 1990
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Adjusted mean Beck Depression Inventory scores did not differ by exposure to overhead 110- to 400-kV power lines (distance and calculated annual average magnetic fields). The risk of severe depression was increased 4.7-fold (95% CI 1.70–13.3) among subjects living within 100 m of a high-voltage power line, but this was based on small numbers.

Outcomes measured

  • Beck Depression Inventory score (self-rated depressive symptoms)
  • Severe depression (as defined by Beck Depression Inventory category)

Limitations

  • Severe depression finding was based on small numbers
  • Exposure assessment relied on distance and calculated annual average magnetic fields (not direct measurements)
View raw extracted JSON
{
  "study_type": "cohort",
  "exposure": {
    "band": "ELF",
    "source": "transmission lines",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "20-year exposure histories before 1990"
  },
  "population": "Participants from the Finnish Twin Cohort Study who completed the Beck Depression Inventory in 1990",
  "sample_size": 12063,
  "outcomes": [
    "Beck Depression Inventory score (self-rated depressive symptoms)",
    "Severe depression (as defined by Beck Depression Inventory category)"
  ],
  "main_findings": "Adjusted mean Beck Depression Inventory scores did not differ by exposure to overhead 110- to 400-kV power lines (distance and calculated annual average magnetic fields). The risk of severe depression was increased 4.7-fold (95% CI 1.70–13.3) among subjects living within 100 m of a high-voltage power line, but this was based on small numbers.",
  "effect_direction": "mixed",
  "limitations": [
    "Severe depression finding was based on small numbers",
    "Exposure assessment relied on distance and calculated annual average magnetic fields (not direct measurements)"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF magnetic fields",
    "high-voltage power lines",
    "transmission lines",
    "depression",
    "Beck Depression Inventory",
    "Finnish Twin Cohort",
    "exposure assessment",
    "distance to power lines"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0,
      "reason": null
    }
  ]
}
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: 10.1093/oxfordjournals.aje.a009232
PubMed: 9420528

Read the original paper →

Related papers

← Back to the Research Library