Abstract: To research if there is injury caused by microwave of hand-set in the brain of mice, microwaves of four kinds of different frequencies and shooting power were used; TBA, DNPH and PMS were used to determine the contents of MDA and activities of LDH and NOS in the brain of the mice after microwave exposure. The contents of MDA and activities of LH did not change(P>0.05) after weak microwave(870, 450 and 45 MHz, 100 mW/cm²) exposure with hand-set and this proved hand-telephones were safe. The content of MDA in the brain of mice increased(P< 0.001), the activity of LDH decreased(P<0.05) and the activity of NOS did not change(P> 0.05) after strong microwave exposure (2450 MHz, 730 mW/cm²), the reactive oxygen free radicals in the brain of the mice was produced after strong microwave (2450 MHz, 730 mW/cm²) exposure and this indicated the oxygen free radicals may participate in the injury in the brain of the mice.

Key words: microwave, MDA, LDH, NOS, mice, brain