Speaker
Description
Introduction: Here we present some initial findings examining the role of blood flow in modulating peak skin temperature rise during local 6 GHz RF-EMF exposures in humans. Methods: Ten young adults [5 female; 23 (SD: 3) years] completed two counterbalanced RF-EMF exposures separated by 20 min involving either blood flow occlusion of the arm or time-matched sham occlusion. Skin temperature on the volar forearm was monitored for 6-min followed by RF-EMF exposure with a horn antenna positioned 50 mm from the skin surface for 6-min. For limb occlusion, a pressure cuff placed on the upper arm was inflated to 40-50 mmHg above systolic blood pressure (5 mmHg for sham) 1 min prior to and throughout RF-EMF exposure. Skin temperature and blood flow were continuously tracked using a high-definition thermal camera and laser speckle contrast imager, respectively. Results: There was a significant effect of blood flow on peak skin temperature (P<0.001), which was 1.2°C [95% CI: 0.6, 1.7] higher at end-exposure with occlusion (40.6°C [40.2, 41.1]) compared to sham occlusion (39.4°C [39.1, 39.9], P<0.001). Peak skin temperature at end-exposure increased by 0.9°C [95% CI: 0.7, 1.2] for every 1°C increase in baseline temperature (P<0.001). Conclusion: Skin blood flow played an important role in modulating peak skin temperature rise during brief localized 6 GHz RF-EMF exposures. Our ongoing work will evaluate skin blood flow effects on peak skin temperature rise during prolonged (30-min) exposures sufficient to allow steady-state skin temperature and blood flow responses to fully develop.
