Effect of microwave irradiation (2450 MHz) on murine cytotoxic lymphocyte and natural killer (NK) cells.

Male Balb/c mice were exposed in an anechoic chamber to 2450 MHz CW microwaves at 5, 10, 15, and 20 mW/cm2, 4 hours daily for 4 days, under controlled environmental conditions. T-cell cytotoxicity and natural killer (NK) cell activity were compared in exposed and sham animals. A significant decrease (p less than 0.001) of cell-mediated cytotoxicity was observed only for a power density of 20 mW/cm2. A significant increase (p less than 0.01) in NK activity was demonstrated following exposures at 15 mW/cm2.