Role of field intensity in the biological effectiveness of millimeter waves at a resonance frequency

Abstract

The study replicated the effect of low-intensity millimeter waves (MMW) on isolated nerve function and characterized its dependence on radiation intensity. MMW exposures lasted for 23 min at 0.02, 0.1, 0.5, or 2.6 mW cm −2 (41.34 GHz) and were accompanied by a high-rate electrical stimulation of the nerve (HRS, 20 twin pulses s −1, 9 ms interpulse interval). MMW had no effect on the conditioning compound action potentials (CAPs), but significantly attenuated the HRS-caused decrease of the test CAPs. The magnitude of this effect was virtually the same (20–25%) at field intensities of 0.02, 0.1, and 2.6 mW cm −2. Irradiation at 0.5 mW cm −2m however, did not produce statistically significant changes. The results are consistent with our earlier observations of this MMW effect and provide further evidence for its nonthermal mechanism.