Erythrocyte hemolysis by radiofrequency fields

A field‐strength‐dependent hemolytic effect of continuous‐wave radiofrequency (RF) exposure in vitro has been demonstrated. Erythrocytes in whole heparinized rabbit blood were hemolyzed by a 2‐h exposure to 50‐ or 100‐MHz RF fields at field strengths of greater than 4 V/cm. An effect of comparable magnitude resulted from exposure to 10‐MHz RF at a field strength of 9 V/cm. Sample temperatures were maintainted at 22.5° ± 0.2°C. There was no apparent involvement of heating or temperature gradients, nor were there any RF exposure effects on cellular K + or Na + concentration, nor on pH. The mechanism of the hemolytic effect is not known. Since the percentage of lysed erythrocytes was less than 1% and there was an absence of effects on cellular cation concentrations, RF radiation may have irreversibly altered the plasma membrane permeability of a sensitive subpopulation of red cells (possibly aged cells) leading to osmotic lysis. RF radiation at these frequencies appears to affect red cells in a manner that is qualitatively and quantitatively different from microwave radiation.