EXPOSURE TO EXTREMELY-LOW-FREQUENCY MAGNETIC-FIELDS HAS NO EFFECT ON GROWTH-RATE OR CLONOGENIC POTENTIAL OF MULTIPOTENTIAL HEMATOPOIETIC PROGENITOR CELLS

Recent reports indicate an increased risk of acute myeloid leukaemia i n children exposed to extremely low frequency magnetic fields (ELFMFs) emitted by high voltage power lines, suggesting that ELFMFs may act a s weak tumour promoters. We have investigated possible interactions of weak ELFMFs with primitive haemopoietic cells in vitro using the mult ipotential progenitor cell Line FDCP-mix(A4). We have determined the p roliferative activity and clonogenic potential of cells under both opt imal and sub-optimal growth conditions and exposed to either ambient l aboratory ELFMFs or three other ELFMF regimes representative of those produced by high voltage power lines: nulled fields, Ca2+-ion cyclotro n resonance conditions at 50 Hz, and vertical 50 Hz fields of 6 mu T-R MS. Using exposures of 1, 4, 7 and 21 days, we found no significant al teration of growth rate, cell-cycle state or clonogenic efficiency ind icating that neither the proliferation nor self-renewal of multipotent ial FDCP-mix(A4) cells was perturbed.