Assessment of the neurotoxic potential of exposure to 50 Hz extremely low frequency electromagnetic fields (ELF-EMF) in naive and chemically stressed PC12 cells

Increasing exposure to extremely low frequency electromagnetic fields (ELF-EMF), generated by power lines and electric appliances, raises concern about potential adverse health effects of ELF-EMF. The central nervous system is expected to be particularly vulnerable to ELF-EMF as its function strongly depends on electrical excitability. We therefore investigated effects of acute (30 min) and sub-chronic (48 h) exposure to 50 Hz ELF-EMF on na ve and chemically stressed pheochromocytoma (PC12) cells. The latter have higher levels of iron and/or reactive oxygen species (ROS) and display increased vulnerability to environmental insults. Effects of ELF-EMF on Ca2+-homeostasis, ROS production and membrane integrity were assessed using Fura-2 single cell fluorescence microscopy, H-2-DCFDA and CFDA assays, respectively. Our data demonstrate that acute exposure of na ve PC12 cells to 50 Hz ELF-EMF up to 1000 mu T fails to affect basal or depolarization-evoked [Ca2+](i). Moreover, sub-chronic ELF-EMF exposure up to 1000 mu T has no consistent effects on Ca2+-homeostasis in na ve PC12 cells and does not affect ROS production and membrane integrity. Notably, in chemically stressed PC12 cells both acute and sub-chronic ELF-EMF exposure also failed to exert consistent effects on Ca2+-homeostasis, ROS production and membrane integrity. Our combined findings thus indicate that exposure to 50 Hz ELF-EMF up to 1000 mu T, i.e. 10,000 times above background exposure, does not induce neurotoxic effects in vitro, neither in na ve nor in chemically stressed PC12 cells. Though our data require confirmation, e.g. in developing neuronal cells in vitro or (developing) animals, it appears that the neurotoxic risk of ELF-EMF exposure is limited. (C) 2014 Elsevier Inc. All rights reserved.