Synergism between sinusoidal-50 Hz magnetic field and formaldehyde in triggering carcinogenic effects in male Sprague-Dawley rats

Am J Ind Med. 2016 Jul;59(7):509-21. doi: 10.1002/ajim.22598. Epub 2016 May 24.


Background: Experimental rodent bioassays performed up to now have failed to provide conclusive confirmation of the carcinogenicity of extremely low frequency magnetic fields (ELFMF).

Objectives: To evaluate the potential synergistic carcinogenic effects of concurrent exposure to ELFMF and formaldehyde in four groups of male and female Sprague-Dawley rats.

Methods: One group was exposed from prenatal life until natural death to S-50 Hz MF and to formaldehyde in drinking water from 6 weeks of age for 104 weeks, two groups were treated only with formaldehyde or only with MF and one group served as untreated control.

Results: Compared to untreated controls, exposure to MF and formaldehyde causes in males a statistically significant increased incidence of malignant tumors (P ≤ 0.01), thyroid C-cell carcinomas (P ≤ 0.01), and hemolymphoreticular neoplasias (P ≤ 0.05). No statistically significant differences were observed among female groups.

Conclusions: Life-span exposure to MF and formaldehyde induces statistically significant carcinogenic effects in male rats. Am. J. Ind. Med. 59:509-521, 2016. © 2016 Wiley Periodicals, Inc.

Keywords: Sprague-Dawley rats; carcinogenic synergism between S-50 Hz MF plus formaldehyde; hemolymphoreticular neoplasias; life-span bioassays; thyroid C-cell carcinomas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogens
  • Cocarcinogenesis*
  • Female
  • Formaldehyde / adverse effects*
  • Hematologic Neoplasms / etiology*
  • Kaplan-Meier Estimate
  • Leukemia / etiology
  • Lymphoma / etiology
  • Magnetic Fields / adverse effects*
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Sex Factors
  • Thyroid Neoplasms / etiology*
  • Thyroid Neoplasms / pathology


  • Carcinogens
  • Formaldehyde