Exposure to 60 Hz magnetic fields does not alter clinical progression of LGL leukemia in Fischer rats.

Carcinogenesis · 1996 · No effect · Moderate evidence

← Research stream

No effectModerate evidencePaper 4201

Study snapshot

PublicationCarcinogenesis · 1996

Study typeanimal

Reported directionNo effect

Evidence ratingModerate

Abstract

Associations between exposure to 60-Hz magnetic fields in residential and occupational environments and the incidence of leukemia and other cancers has been suggested by the results of a number of epidemiology studies. To address these potential associations, a study has been conducted to determine if 60-Hz magnetic fields can alter the clinical progression of leukemia. In the large granular lymphocytic (LGL) leukemia model, spleen cells from aged leukemic rats were transplanted into young, male Fischer 344 rats, producing leukemia in a relatively short period. A total of 72 animals were randomly assigned to four treatment groups (18/group) as follows: (1) 10 G; (2) sham exposed (null energized field) (approximately 20 mG); (3) ambient controls (<1 mG); and (4) positive controls (5 Gy whole body irradiation from Cobalt-60, 4 days before initiation of exposure). At the initiation of exposure or sham-exposure, all rats were injected (i.p.) with 2.2x10(7) fresh, viable, LGL leukemia cells. The magnetic fields were activated for 20 h per day, 7 days per week; all exposure conditions were superimposed over the natural ambient magnetic field. Eighteen rats from each treatment were bled at weeks 0, 2, 4, 5, 6, 7, 8 and 10 to monitor, in the same set of animals, the clinical progression of the LGL disease and survival of the animals. Peripheral blood hematological changes were monitored to evaluate the progression of the leukemia. In general, no significant or consistent differences were detected between the magnetic field exposed and the ambient field control groups, although some inconsistent and random differences were occasionally observed. These data indicate that the 10 G magnetic fields did not significantly alter the clinical progression of LGL leukemia in Fischer 344 rats.

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 typeanimal

Effect directionno_effect

PopulationYoung, male Fischer 344 rats injected i.p. with transplanted LGL leukemia cells

Sample size72

ExposureELF · 0.06 MHz · 20 h/day, 7 days/week (followed through week 10)

Evidence strengthModerateConfidence: 78% · Peer reviewed: yes

Main findings

Across repeated blood monitoring through week 10, no significant or consistent differences were detected between the 10 G 60-Hz magnetic-field exposed group and the ambient field control group; occasional differences were described as inconsistent and random. The authors conclude that 10 G 60-Hz magnetic fields did not significantly alter clinical progression of LGL leukemia in Fischer 344 rats.

Outcomes measured

Clinical progression of LGL leukemia
Survival
Peripheral blood hematological changes

Limitations

Animal model (Fischer 344 rats with transplanted LGL leukemia) may not generalize to humans
Exposure intensity tested was 10 G; other field strengths not assessed
Exposure conditions were superimposed over natural ambient magnetic field
Some differences were observed but described as inconsistent/random; details not provided in abstract

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": 0.06,
    "sar_wkg": null,
    "duration": "20 h/day, 7 days/week (followed through week 10)"
  },
  "population": "Young, male Fischer 344 rats injected i.p. with transplanted LGL leukemia cells",
  "sample_size": 72,
  "outcomes": [
    "Clinical progression of LGL leukemia",
    "Survival",
    "Peripheral blood hematological changes"
  ],
  "main_findings": "Across repeated blood monitoring through week 10, no significant or consistent differences were detected between the 10 G 60-Hz magnetic-field exposed group and the ambient field control group; occasional differences were described as inconsistent and random. The authors conclude that 10 G 60-Hz magnetic fields did not significantly alter clinical progression of LGL leukemia in Fischer 344 rats.",
  "effect_direction": "no_effect",
  "limitations": [
    "Animal model (Fischer 344 rats with transplanted LGL leukemia) may not generalize to humans",
    "Exposure intensity tested was 10 G; other field strengths not assessed",
    "Exposure conditions were superimposed over natural ambient magnetic field",
    "Some differences were observed but described as inconsistent/random; details not provided in abstract"
  ],
  "evidence_strength": "moderate",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "60 Hz",
    "extremely low frequency",
    "magnetic fields",
    "leukemia progression",
    "large granular lymphocytic leukemia",
    "Fischer 344 rats",
    "sham exposure",
    "ambient control",
    "positive control irradiation"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.25,
      "reason": "Motivated by residential/occupational ELF magnetic-field epidemiology; tests biological effect of 60-Hz magnetic fields."
    }
  ]
}

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/carcin/17.12.2681
PubMed: 9006106

Read the original paper →

Related papers

← Back to the Research Library