RF Safe

Effects of electromagnetic fields on the immune systems of occupationally exposed humans and mice.

Archives of environmental health · 2003 · Harm · Very low evidence

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HarmVery low evidencePaper 3694

In humans occupationally exposed to low-frequency magnetic fields (0.2–6.6 microT), exposed subjects had significantly lower total lymphocyte, CD4, and CD3 counts and significantly higher NK cells versus matched controls; 6 months after exposure cessation, ly…

Study snapshot

PublicationArchives of environmental health · 2003
Study typeother
Reported directionHarm
Evidence ratingVery low

Abstract

The authors examined immunological disorders in 6 individuals who had been exposed occupationally to environmental electromagnetic fields. Comparable effects on mice exposed in a similar environment were also investigated. The human subjects had worked 8 hr/day for 5 yr in a laboratory located above electrical transformers and high-tension cables, and in which there were low-frequency electromagnetic fields of 0.2-6.6 microtesla (microT). The 6 control subjects (matched for socioeconomic parameters, sex, and age) had worked away from the immediate vicinity of transformers and high-tension cables. The authors found statistically significantly lower total lymphocyte, CD4, and CD3 counts, and significantly increased natural killer (NK) cells, in exposed subjects vs. controls. Six months after exposure had ceased, total lymphocyte counts had increased, as had CD4, CD3, and CD19 counts (+13%, +28%, +22%, and +17%, respectively), and NK cell counts were decreased by 26% (not significant) in the same human subjects. In the second part of this study, 12 Swiss male mice housed in cages were exposed in the same room in which the human subjects had been exposed (i.e., 5-microT, 50-Hz magnetic field) for 109 days; 12 additional mice were used as unexposed controls. The total lymphocyte, leukocyte, polymorphonuclear neutrophil, CD4, and NK counts of the exposed mice at 109 days were significantly lower than those of controls. In addition, plasma glucose levels (at 30 days) and amylase activity (at 109 days) were significantly lower, whereas plasma sodium and chloride levels were significantly elevated at 109 days. Results from this study suggest that chronic exposure to a 0.2-6.6-microT magnetic field can lead to decreased immunological parameters (total lymphocytes and CD4 counts) in both humans and mice. The increase in some values once exposure was terminated suggests a causal relationship with exposure to electromagnetic fields, as do the changes in mice, particularly the changes in total lymphocyte and CD4 counts.

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 typeother
Effect directionharm
Population6 occupationally exposed humans and 6 matched controls; Swiss male mice (12 exposed, 12 controls)
Sample size36
ExposureELF · Humans: 8 hr/day for 5 yr; Mice: 109 days
Evidence strengthVery lowConfidence: 74% · Peer reviewed: yes

Main findings

In humans occupationally exposed to low-frequency magnetic fields (0.2–6.6 microT), exposed subjects had significantly lower total lymphocyte, CD4, and CD3 counts and significantly higher NK cells versus matched controls; 6 months after exposure cessation, lymphocyte-related counts increased and NK counts decreased (not significant). In mice exposed to a 5-microT, 50-Hz magnetic field for 109 days, several immune cell counts (including total lymphocyte and CD4) were significantly lower than controls, along with changes in some blood chemistry measures.

Outcomes measured

  • Total lymphocyte count
  • CD4 count
  • CD3 count
  • CD19 count
  • Natural killer (NK) cell count
  • Leukocyte count
  • Polymorphonuclear neutrophil count
  • Plasma glucose level
  • Amylase activity
  • Plasma sodium level
  • Plasma chloride level

Limitations

  • Very small human sample (6 exposed, 6 controls)
  • Exposure characterization limited to magnetic field intensity range; limited detail on other potential exposures in the laboratory setting
  • Non-randomized observational comparison in humans (occupational setting)
  • Animal experiment details beyond exposure duration and field strength are limited in the abstract
View raw extracted JSON
{
  "study_type": "other",
  "exposure": {
    "band": "ELF",
    "source": "occupational",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "Humans: 8 hr/day for 5 yr; Mice: 109 days"
  },
  "population": "6 occupationally exposed humans and 6 matched controls; Swiss male mice (12 exposed, 12 controls)",
  "sample_size": 36,
  "outcomes": [
    "Total lymphocyte count",
    "CD4 count",
    "CD3 count",
    "CD19 count",
    "Natural killer (NK) cell count",
    "Leukocyte count",
    "Polymorphonuclear neutrophil count",
    "Plasma glucose level",
    "Amylase activity",
    "Plasma sodium level",
    "Plasma chloride level"
  ],
  "main_findings": "In humans occupationally exposed to low-frequency magnetic fields (0.2–6.6 microT), exposed subjects had significantly lower total lymphocyte, CD4, and CD3 counts and significantly higher NK cells versus matched controls; 6 months after exposure cessation, lymphocyte-related counts increased and NK counts decreased (not significant). In mice exposed to a 5-microT, 50-Hz magnetic field for 109 days, several immune cell counts (including total lymphocyte and CD4) were significantly lower than controls, along with changes in some blood chemistry measures.",
  "effect_direction": "harm",
  "limitations": [
    "Very small human sample (6 exposed, 6 controls)",
    "Exposure characterization limited to magnetic field intensity range; limited detail on other potential exposures in the laboratory setting",
    "Non-randomized observational comparison in humans (occupational setting)",
    "Animal experiment details beyond exposure duration and field strength are limited in the abstract"
  ],
  "evidence_strength": "very_low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "ELF",
    "50 Hz",
    "magnetic field",
    "occupational exposure",
    "transformers",
    "high-tension cables",
    "immune system",
    "lymphocytes",
    "CD4",
    "CD3",
    "NK cells",
    "mouse study"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.9,
      "reason": "Study examines immune parameters in humans occupationally exposed to ELF magnetic fields near transformers/high-tension cables, with matched controls."
    }
  ]
}
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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: 10.3200/aeoh.58.11.712-717
PubMed: 15702897

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