R. Mandeville et al., EVALUATION OF THE POTENTIAL CARCINOGENICITY OF 60 HZ LINEAR SINUSOIDAL CONTINUOUS-WAVE MAGNETIC-FIELDS IN FISCHER F344 RATS, The FASEB journal, 11(13), 1997, pp. 1127-1136
Electric and magnetic fields (EMFs) associated with the production, tr
ansmission, and use of electricity are ubiquitous in industrialized so
cieties. These fields are predominantly of low frequency (50/60 Hz) an
d are generally of low intensity. Review of the epidemiological eviden
ce shows that the association between exposure to EMFs and cancer is w
eak and inconsistent, and generally fails to show a dose-response rela
tionship. Moreover, in view of the methodological problems of these ep
idemiological studies, animal and laboratory studies are urgently need
ed to determine whether EMFs could be initiators and/or promoters of c
ancers. The objective of the present study was to determine whether ch
ronic exposure to 60 Hz linear (single axis) sinusoidal, continuous-wa
ve magnetic fields (MFs) of different intensities might increase the r
isk of leukemia and solid tumor development in rodents born and raised
under these fields. Five groups of 50 female F344 rats were exposed f
or 20 h/day to 60 Hz MFs at intensities of <0.02 (sham controls), 2, 2
0, 200, and 2000 mu T. Full body exposure to the different fields was
administered for 104 wk starting from the prenatal period (2 days befo
re birth) and continuing during lactation and weaning until late adult
Life. Body weight, survival, and clinical observations were evaluated
in all groups of animals during in-life exposure. Necropsy was perfor
med on all exposed and control animals that died, were found moribund,
or were killed at termination of the study. To preserve and demonstra
te the absence of any experimental bias, all clinical observations and
pathological evaluations were conducted under ''blinded'' conditions.
Fifty organs and tissues were evaluated in each animal, with special
attention to the incidence of mononuclear cell leukemia, brain tumors,
and mammary tumors. The findings from this chronic carcinogenicity st
udy dem onstrate that, under our defined experimental conditions, expo
sure to 60 Hz linear (single axis) sinusoidal, continuous wave MFs did
not affect animal survival, solid tumor, or mononuclear cell leukemia
development in female F344 rats. No statistically significant, consis
tent, positive dose-related trends with the number of tumor-bearing an
imals per study group could be attributed to MF exposure.