O'Connor RP, Madison SD, Leveque P, Roderick HL, Bootman MD. (2010). Exposure to GSM RF fields does not affect calcium homeostasis in human endothelial cells, rat pheocromocytoma cells or rat hippocampal neurons. PLoS One. 5(7):e11828.
Calcium (Ca2+) modulates various cellular activities. Results from studies of possible effects of radiofrequency fields (RF) on Ca2+ homeostasis in mammalian cells are controversial. Some studies suggest that Ca2+ homeostasis is affected by RF fields emitted by mobile phones, while other studies provide no evidence for such effects.
The objective of this study was to establish whether there was an interaction between RF radiation and cellular Ca2+.
Three cell types were used in these experiments: human endothelial cells, PC-12 neuroblastoma cells, and primary hippocampal neurons. It was suggested in earlier studies that these cells were sensitive to RF fields. Changes in cellular Ca2+ during exposure of mammalian cells to 900 MHz GSM of different power (specific absorption rates of 0.012 to 2.0 W/kg) were monitored using a microscope-based fluorescence imaging screening system. For comparison, paired experiments were conducted with continuous wave fields or sham exposure. The screening phase consisted of 3 periods of 30 minutes each. Baseline Ca2+ concentrations were determined in the first 30 minutes. During the following 30 minutes, cells were exposed to RF field or sham exposed. The final 30 minutes were intended to determine persistence and reversibility of putative changes potentially induced by the RF exposure. During the provocation phase, Ca2+ signals were induced by pharmacological manipulations; the cells were exposed to RF or sham-exposed to examine possible effects of the exposure on provoked Ca2+ signals.
Results and Interpretation
Ca2+ homeostasis or provoked Ca2+ signals were not affected either by continuous wave field or by pulsed 900 MHz GSM signal even at the highest field strength. The authors explained the discrepancy between this result and results from some other studies by differences in methodology, tissue conditions, and RF signals used.
The authors concluded that, under the conditions of their experiments, no effect of RF exposure could be detected by a highly sensitive assay.