Abstract

Overview

This study addresses the concerns surrounding human exposure to radiofrequency (RF) and microwave energy, particularly focusing on the scenarios involving high-power pulsed RF/microwave energy which can lead to stress waves within the body due to rapid thermal expansion.

Methodology

• A computational model was employed to estimate temperature profiles in the human brain from exposure to varying RF/microwave incident field parameters.
• These temperature profiles were then used to simulate the mechanical responses of the brain.

Findings

Simulations revealed that certain extremely high-power microwave exposures, still permissible under current safety standards, could induce very high stresses within the brain. These stresses have potential implications for causing neuropathological effects. Although such power densities are significantly larger than typical real-world exposure conditions, they remain achievable in military and research applications utilizing devices designed to emit high-power electromagnetic pulses.

Important Observations

• Low intracranial absorption at specific frequencies raises concerns regarding peak intracranial SAR compared to skin SAR.
• Even a small temperature increase in microseconds can produce potentially injurious stress waves.

Conclusion

While adverse health effects via the mechanics explored—known as microwave auditory effects or the Frey effect—have not yet been established conclusively, studies suggest high-peak power pulsed microwaves may indeed have cognitive impacts. It’s crucial to consider these findings in developing future safety standards and guidelines.