Haemopoietic cell proliferation in murine bone marrow cells exposed to extreme low frequency (ELF) electromagnetic fields

As leukemia is one of the health hazards that is sometimes associated with exposure to extreme low frequency fields, we studied the in vitro effects o f ELF fields on haemopoietic cell proliferation. First, the cytotoxic effec t of 80 muT, 50 Hz magnetic fields on 3T3 cell proliferation was investigat ed using the neutral red test. Many chemicals are believed to cause damage because they interfere with basal or "housekeeping" cell functions. The bas al cell functions are present in every cell. Non-specialized, actively divi ding cells are suitable for measuring cytotoxic effects. Cytotoxic doses ca n be identified by exposing actively dividing cells in vitro and measuring growth inhibition caused by interference with these basal cell functions. 8 0 muT, 50 Hz magnetic fields caused no cytotoxicity: we were not able to de monstrate any interference with essential cell functions in the non-differe ntiated 3T3 cell line. Furthermore, the in vitro effects of ELF fields on m urine haemopoietic and stromal stem cell proliferation were studied. Haemop oiesis is a continuous process, where mature blood cells are replaced by th e proliferation and differentiation of more primitive progenitor and stem c ells. Blood formation is. tightly regulated by the stromal micro-environmen t. Exposure of murine bone marrow cells, from male and female mice, to 80 m uT (50 Hz) magnetic fields showed a reduction in the proliferation and diff erentiation of the granulocyte-macrophage progenitor (CFU-GM) compared to n on-exposed bone marrow cells. The results on the effect of the ELF-field on stromal stem cell proliferation (CFU-f) are somewhat equivocal at the mome nt. CFU-f from female mice showed a reduction while CFU-f from male mice we re not decreased. (C) 2001 Elsevier Science Ltd. All rights reserved.