Purpose: The purpose of this investigation was to determine whether early t
reatment with ionizing radiation and/or chronic magnetic field (MF) exposur
e affected body weight in female mice.
Materials and methods: Weanling C57BL/6 female mice were irradiated with fo
ur equal weekly cobalt-60 exposures (total cumulative closes: 3.0, 4.0, 5.1
Gy) and/or received chronic lifetime exposure to 1.4mT 60Hz circularly pol
arized MF or ambient MF. The body weights of 2280 mice were recorded at 35
age intervals, and analysis of variance was used to compare the mean differ
ences from baseline weights between treatment groups and sham-exposed contr
Results: A highly statistically significant effect of ionizing radiation on
body Weight was observed at 28 age intervals (p less than or equal to0.001
), and for MF exposure at 10 age intervals (p less than or equal to0.001).
During the young adult growth phase, mice exposed only to MF exhibited less
than or equal to0.5g greater weight gain relative to sham-exposed controls
(p=0.0001). The effect of ionizing radiation alone was inversely related t
o close, with the largest weight increases observed in all of the irradiate
d groups after 9-12 months (p=0.0001).
Conclusions: Treatment with split-dose ionizing radiation at an early age a
nd chronic exposure to a residential power frequency NIF were Found to prod
uce small but significant increases in body weight.