Microwave radiation-induced calcium ion efflux from human neuroblastoma cells in culture

Monolayer cultures of human neuroblastoma cells were exposed to 915-MHz radiation, with or without sinusoidal amplitude modulation (80%) at 16 Hz, at specific absorption rates (SAR) for the culture medium and cells of 0.00, 0.01, 0.05, 0.075, 0.1, 0.5, 0.75, 1.0, 1.5, 2, or 5 mW/g. A significant increase in the efflux of calcium ions (45Ca2+) as compared to unexposed control cultures occurred at two SAR values: 0.05 and 1 mW/g. Increased efflux at 0.05 mW/g was dependent on the presence of amplitude modulation at 16 Hz but at the higher value it was not. These results indicate that human neuroblastoma cells are sensitive to extremely low levels of microwave radiation at certain narrow ranges of SAR.