THE GENOTOXIC POTENTIAL OF ELECTRIC AND MAGNETIC-FIELDS - AN UPDATE

We review 23 studies on the potential genotoxicity of electric and mag netic fields that have appeared in the published literature since our 1993 review of 55 published studies (McCann et al., Mutat. Res. 297 (1 993) 61-95) and six additional studies published prior to 1993, which were not previously reviewed. As in our previous review, internal elec tric fields present in media (for in vitro experiments) and in the tor so (for in vivo experiments) were estimated. Individual experiments ar e evaluated using basic data quality criteria. The potential for genot oxicity of electric and magnetic fields is discussed in light of the s ignificant body of genotoxicity data that now exists. Three unsuccessf ul attempts to replicate previously reported positive results have app eared since our previous review. We conclude that, in spite of the 34 studies reviewed in this and our previous publication that report posi tive genotoxic effects, none satisfy all of three basic conditions: in dependent reproducibility, consistency with the scientific knowledge b ase, and completeness according to basic data quality criteria. As we discuss, these criteria are satisfied for several groups of negative s tudies in several exposure categories (ELF magnetic fields, 150 mu T-5 mT, combined ELF electric and ELF magnetic fields, approx. 0.2 mT, 24 0 mV/m, and static magnetic fields, 1-3.7 T). The evidence reviewed he re strengthens the conclusion of our previous review, that the prepond erance of evidence suggests that ELF electric or magnetic fields do no t have genotoxic potential. Nevertheless, a pool of positive results r emains, which have not yet been tested by independent replication. Amo ng the 12 studies reviewed here, which report statistically significan t or suggestive positive results, we point particularly to results fro m five laboratories [J. Miyakoshi, N. Yamagishi, S. Ohtsu, K. Mohri, H . Takebe, Increase in hypoxanthine-guanine phosphoribosyl transferase gene mutations by exposure to high-density 50-Hz magnetic fields, Muta t. Res. 349 (1996) 109-114; J. Miyaitoshi, K. Kitagawa, H. Takebe, Mut ation induction by high-density, 50-Hz magnetic fields in human MeWo c ells exposed in the DNA synthesis phase, Int. J. Radiat. Biol. 71 (199 7) 75-79; H. Lai. N.P. Singh, Acute exposure to a 60-Hz magnetic field increases DNA strand breaks in rat brain cells, Bioelectromagnetics, 18 (1997) 156-165; H. Lai, N.P. Singh, Melatonin and N-tert-butyl-alph a-phenylnitrone block 60-Hz magnetic field-induced DNA single and doub le strand breaks in rat brain cells, J. Pineal Res. 22 (1997) 152-162; T. Koana, M. Ikehata, M. Nakagawa Estimation of genetic effects of a static magnetic field by a somatic cell test using mutagen-sensitive m utants of Drosophila melanogaster, Bioelectrochem. Bioenergetics 36 (1 995) 95-100 F.L. Tabrah, H.F. Mower, S. Batkin, P.B. Greenwood, Enhanc ed mutagenic effect of a 60-Hz time-varying magnetic field on numbers of azide-induced TA100 revertant colonies. Bioelectromagnetics 15 (199 4) 85-93; S. Tofani, A. Ferrara, L. Anglesio, G. Gilli, Evidence for g enotoxic effects of resonant ELF magnetic fields, Bioelectrochem. Bioe nergetics, 36 (1995) 9-13], which satisfy most basic data quality crit eria and may be of interest. (C) 1998 Elsevier Science B.V. All rights reserved.