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Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

Cancer & Tumors

Effect of 13 week magnetic field exposures on DMBA-initiated mammary gland carcinomas in female Sprague- Dawley rats

No Effects Found

Authors not listed · 1999

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Thirteen weeks of power line frequency magnetic field exposure showed no cancer-promoting effects in chemically-induced rat breast tumors.

Plain English Summary

Summary written for general audiences

Researchers exposed 400 female rats to 50 Hz and 60 Hz magnetic fields for 13 weeks after chemically inducing breast cancer with DMBA. The magnetic fields at 1-5 gauss strength showed no effect on tumor development, size, or timing compared to unexposed controls.

Why This Matters

This carefully designed study provides reassuring evidence that power line frequency magnetic fields don't promote breast cancer development in laboratory animals. The researchers used DMBA, a potent carcinogen, to create a cancer-prone environment where any tumor-promoting effects would be easily detectable. The field strengths tested (1-5 gauss) are significantly higher than typical household exposures, which range from 0.5-4 milligauss near appliances. What makes this study particularly valuable is its large sample size of 400 animals and rigorous 13-week exposure protocol. The finding that magnetic fields actually showed a slight protective effect in one group challenges assumptions about EMF harm. While animal studies don't always translate directly to humans, this research suggests that everyday exposure to power line frequencies from household wiring and appliances is unlikely to promote breast cancer development.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 50-60 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 50-60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Cite This Study
Unknown (1999). Effect of 13 week magnetic field exposures on DMBA-initiated mammary gland carcinomas in female Sprague- Dawley rats.
Show BibTeX
@article{effect_of_13_week_magnetic_field_exposures_on_dmba_initiated_mammary_gland_carcinomas_in_female_sprague_dawley_rats_ce1557,
  author = {Unknown},
  title = {Effect of 13 week magnetic field exposures on DMBA-initiated mammary gland carcinomas in female Sprague- Dawley rats},
  year = {1999},
  doi = {10.1093/carcin/20.8.1615},
  
}
DOI: 10.1093/carcin/20.8.1615PubMed: 10426815

Quick Questions About This Study

This study found no evidence that 50 Hz magnetic fields promote breast cancer in female rats, even after 13 weeks of daily exposure at field strengths up to 5 gauss following chemical tumor induction.
The study used 1-5 gauss magnetic fields, which are 250-1,250 times stronger than typical household appliance exposures of 0.5-4 milligauss, making this a very conservative safety test.
Despite DMBA creating a cancer-prone environment where tumor-promoting effects would be easily detected, magnetic field exposure showed no increase in tumor development, suggesting no enhanced EMF sensitivity.
Magnetic field exposure for 18.5 hours per day had no effect on when mammary tumors first appeared compared to unexposed control rats in either study.
Both 50 Hz and 60 Hz magnetic fields at 1 gauss showed similar results with no cancer-promoting effects, indicating no meaningful difference between these power line frequencies.