Genotoxicity Induced by Fetal & Infant Exposure to Magnetic Fields & Ionizing Radiation
Udroiu I, Antoccia A, Tanzarella C, Giuliani L, Pacchierotti F, Cordelli E, Eleuteri P, Villani P, Sgura A.Genotoxicity Induced by Foetal and Infant Exposure to Magnetic Fields and Modulation of Ionising Radiation Effects. PLoS One. 2015 Nov 11;10(11):e0142259. doi: 10.1371/journal.pone.0142259. eCollection 2015.
BACKGROUND: Few studies have investigated the toxicity and genotoxicity of extremely low frequency magnetic fields (ELF-MF) during prenatal and neonatal development. These phases of life are characterized by cell proliferation and differentiation, which might make them sensitive to environmental stressors. Although in vitro evidences suggest that ELF-MF may modify the effects of ionizing radiation, no research has been conducted so far in vivo on the genotoxic effects of ELF-MF combined with X-rays.
AIM AND METHODS: Aim of this study was to investigate in somatic and germ cells the effects of chronic ELF-MF exposure from mid gestation until weaning, and any possible modulation produced by ELF-MF exposure on ionizing radiation-induced damage. Mice were exposed to 50 Hz, 65 μT magnetic field, 24 hours/day, for a total of 30 days, starting from 12 days post-conception. Another group was irradiated with 1 Gy X-rays immediately before ELF-MF exposure, other groups were only X-irradiated or sham-exposed. Micronucleus test on blood erythrocytes was performed at multiple times from 1 to 140 days after birth. Additionally, 42 days after birth, genotoxic and cytotoxic effects on male germ cells were assessed by comet assay and flow cytometric analysis.
RESULTS: ELF-MF exposure had no teratogenic effect and did not affect survival, growth and development. The micronucleus test indicated that ELF-MF induced a slight genotoxic damage only after the maximum exposure time and that this effect faded away in the months following the end of exposure. ELF-MF had no effects on ionizing radiation (IR)-induced genotoxicity in erythrocytes. Differently, ELF-MF appeared to modulate the response of male germ cells to X-rays with an impact on proliferation/differentiation processes.
These results point to the importance of tissue specificity and development on the impact of ELF-MF on the early stages of life and indicate the need of further research on the molecular mechanisms underlying ELF-MF biological effects.
Pregnant CD-1 Swiss (outbred) mice (Charles River, Italy) were divided into four groups, comprising two dams each. One group was unexposed and served as control (C, 27 pups); another group (E, 20 pups) was exposed to ELF-MF from day 11.5 post conception (p.c.) until weaning, for a total of 30 days; another group (X, 25 pups) was X-irradiated [1 Gy) on day 11.5 p.c.; the last group (XE, 31 pups) was X-irradiated (1 Gy) on day 11.5 p.c. and immediately exposed to ELF magnetic fields until weaning (30 days in total).
For this experiment, we employed a magnetic field of 65 μT. Since mice require a 12-26-fold greater MF exposure than that required by humans to induce similar current density within the body , the field we used is (in term of biological effects) comparable to a 2–5 μT MF for humans. These values are usually present in most households.
Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley
Electromagnetic Radiation Safety
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