Cytogenetic investigations were performed in human peripheral blood lymphoc
ytes following exposure to 50 Hz magnetic fields alone or in combination wi
th the chemical mutagen mitomycin C or with X-rays. It was found that magne
tic fields up to 2500 muT did not significantly influence the chromosome ab
erration and sister chromatid exchange frequency. Also, the combined treatm
ents failed to indicate the presence of any synergistic, potentiating, or a
ntagonistic effect between the ELF magnetic fields and the mutagens. Howeve
r, there were two exceptions: Cells exposed to 504 muT magnetic fields befo
re and during cultivation displayed a statistically significant decrease in
sister chromatid exchange frequency. Also, when cells were cultivated in t
he presence of 88.4 muT magnetic fields following X-ray exposures there was
a significant increase in chromosome aberration frequency compared to X-ra
y exposure alone. Bioelectromagnetics 21:589-596, 2000. (C) 2000 Wiley-Liss
, Inc.