Reassessing Laboratory Results of Low-Frequency Electromagnetic Field Exposure of Cells in Culture

A systematic measurement has shown that the background static and ELF magnetic fields in biological incubators can vary by orders of magnitude within a single incubator and between different incubators. Measured incubator fields varied from below levels that the IARC had classified as possibly carcinogenic to humans (0.3 mu T to 0.4 mu T) to as high as 240 mu T, above the Earth or natural geomagnetic field range (23 mu T to 65 mu T). The significance is that studies of biological effects of ELF field exposure on cell cultures involved magnetic fields ranging from 0.1 mu T to 50 mu T. The inconsistency or variability of in vitro laboratory data prompted many to declare that there was no compelling evidence that biological effects are causally related to ELF magnetic-field exposure. Most in vitro investigations involving cell cultures in the laboratory were unaware of and therefore did not account for the large variations in background static and ELF magnetic fields in cell-culture incubators. Given the potential confounding of unspecified incubator fields, it seems only reasonable to reassess the data and reevaluate the validity of any conclusions to date, positive or negative. Are we back to square one? In some sense, it may be so: the reported background static and ELF magnetic-field variations in cell-culture incubators could be a game changer.