EXPOSURE TO 100 HZ PULSED MAGNETIC-FIELDS INCREASES MICRONUCLEUS FREQUENCY AND CELL-PROLIFERATION IN HUMAN-LYMPHOCYTES

The genotoxic effect of a 100 Hz pulsed magnetic field (PMF) in human peripheral blood lymphocyte cultures from 25 healthy subjects was inve stigated. For this purpose, the cytokinesis-block micronucleus assay ( MN), using two concentrations of cytochalasin-B (Cyt-B; 3 and 6 mu g m l(-1)), was applied to evaluate the micronucleus frequency in unexpose d and PMF-exposed cultures obtained from blood of the same subjects. C ell proliferation was also evaluated applying the cytokinesis-block pr oliferation index (CBPI), which indicates the average number of cell c ycles undergone by a given cell. The results obtained indicate that, u nder the experimental conditions used in this study, 72 h 100 Hz PMF e xposure produced a statistically significant increase of both MN and C BPI in exposed cultures with respect to unexposed ones, at variance wi th previous results showing no genotoxic effects with 50 Hz pulsed mag netic fields, used for therapeutic bone repair. (C) 1997 Elsevier Scie nce S.A.