Microwave irradiation (f=36 GHz) changes the properties of distilled w
ater within the first 1-10 min. The new state is retained for at least
tens of minutes and manifests itself as changes in power density spec
trum of periodic fading voltage fluctuations that are generated during
discharge of a capacitor in which water is used as a dielectric. It i
s assumed that long-term changes in water properties mediate the effec
t of electromagnetic fields on biological systems.