Effects of extremely low frequency electromagnetic fields on hematologic and immunologic parameters in welders.

Archives of medical research · 2002 · Mixed · Low evidence

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MixedLow evidencePaper 5307

Study snapshot

PublicationArchives of medical research · 2002

Study typecross_sectional

Reported directionMixed

Evidence ratingLow

Abstract

BACKGROUND: Electric arc welding is known to cause considerable exposure to extremely low frequency magnetic fields. Although some studies of exposure to magnetic fields and epidemiologic studies have included groups of welders, typically little information is available concerning the hematologic and immunologic effects of ELF electromagnetic fields on welders. Therefore, the aim of the present study is to investigate whether or not extremely low frequency electromagnetic fields (ELF EMF) emitted from electric arc welding affect some hematologic and immunologic parameters of welders. METHODS: The study was carried out on 16 male welders and 14 healthy males between 20 and 40 years of age from the same geographic area and with similar life styles. The following hematologic and immunologic parameters were measured in both groups: red blood cells (RBC); hemoglobin (Hgb); hematocrit (Hct); platelets (Plt); total white blood cells (WBC); neutrophils; lymphocytes; eosinophils; and CD3, CD4, CD8, and CD4/CD8. RESULTS: Some of the hematologic and immunologic parameters under investigation were similar in both groups. Although T lymphocyte surface antigens, such as levels of CD4 and CD8(,) were found to be lower in the welders than in the control subjects (p <0.001, p <0.05), the hematocrit levels of the welders were found to be higher than those of the control subjects (p <0.05). However, the differences observed were not clinically significant. ELF electromagnetic field intensities in the welding areas varied between 0.10 and 0.25 mT. CONCLUSIONS: These results suggest that ELF electromagnetic fields do not affect the hematologic and immunologic parameters of welders.

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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 typecross_sectional

Effect directionmixed

PopulationMale welders (age 20–40) and healthy male controls from same geographic area with similar lifestyles

Sample size30

ExposureELF

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Most measured hematologic and immunologic parameters were similar between welders and controls. CD4 and CD8 levels were lower in welders (p<0.001 and p<0.05), and hematocrit was higher in welders (p<0.05), but differences were reported as not clinically significant. ELF magnetic field intensities in welding areas ranged from 0.10 to 0.25 mT; authors conclude ELF EMF do not affect these parameters.

Outcomes measured

Red blood cells (RBC)
Hemoglobin (Hgb)
Hematocrit (Hct)
Platelets (Plt)
Total white blood cells (WBC)
Neutrophils
Lymphocytes
Eosinophils
CD3
CD4
CD8
CD4/CD8 ratio

Limitations

Small sample size (16 welders, 14 controls)
Cross-sectional comparison (cannot establish causality)
Exposure characterized only by area field intensity range; individual exposure metrics and duration not reported
Clinical significance noted as absent despite statistical differences

View raw extracted JSON

{
  "study_type": "cross_sectional",
  "exposure": {
    "band": "ELF",
    "source": "occupational (electric arc welding)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Male welders (age 20–40) and healthy male controls from same geographic area with similar lifestyles",
  "sample_size": 30,
  "outcomes": [
    "Red blood cells (RBC)",
    "Hemoglobin (Hgb)",
    "Hematocrit (Hct)",
    "Platelets (Plt)",
    "Total white blood cells (WBC)",
    "Neutrophils",
    "Lymphocytes",
    "Eosinophils",
    "CD3",
    "CD4",
    "CD8",
    "CD4/CD8 ratio"
  ],
  "main_findings": "Most measured hematologic and immunologic parameters were similar between welders and controls. CD4 and CD8 levels were lower in welders (p<0.001 and p<0.05), and hematocrit was higher in welders (p<0.05), but differences were reported as not clinically significant. ELF magnetic field intensities in welding areas ranged from 0.10 to 0.25 mT; authors conclude ELF EMF do not affect these parameters.",
  "effect_direction": "mixed",
  "limitations": [
    "Small sample size (16 welders, 14 controls)",
    "Cross-sectional comparison (cannot establish causality)",
    "Exposure characterized only by area field intensity range; individual exposure metrics and duration not reported",
    "Clinical significance noted as absent despite statistical differences"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF EMF",
    "magnetic fields",
    "electric arc welding",
    "occupational exposure",
    "hematology",
    "immunology",
    "CD4",
    "CD8",
    "hematocrit"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.9,
      "reason": "Study evaluates ELF magnetic field exposure in welders and related blood/immune parameters."
    }
  ]
}

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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/s0188-4409(01)00337-x
PubMed: 11825628

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