To study the effects of 1h exposure to an 1800 µT, 60 Hz magnetic field on human microcirculation (skin blood perfusion) and macrocirculation (heart rate, low frequency heart rate variability (0.04-0.15 Hz), and high frequency heart rate variability (0.15-0.4 Hz)).
58 subjects participated in this study consisting of two testing sessions (real exposure and sham exposure) administered on separate days. Each session included four consecutive blocks of measurements, separated by 15 min rest periods.
|Exposure duration||continuous for 1 h|
|Setup||pair of Helmholtz-like coils with a diameter of 1.6 m, 1.2 m apart; each coil consisted of 80 turns of AWG10 wiring and water tubes to prevent coil heating; test person seated between the coils; field homogeneous at head level|
|Sham exposure||A sham exposure was conducted.|
No effect of a 60 Hz magnetic field exposure at 1800 µT was demonstrated on skin blood perfusion or any of the ECG parameters recorded. The data suggest that magnetic field exposure tends to marginally increase skin surface temperature, mainly when a subject is exposed first prior to the sham exposure condition. However, small fluctuations in ambient room temperature might have been a confounder in this experiment. Indeed, the fact that skin surface temperatures remained steady over the exposure session while decreasing in the sham exposure session might be the consequence of a small room heating effect of half a degree produced by the exposure system functioning. Nevertheless, the hypothesis of a magnetic field effect on superficial skin temperature regulation cannot be excluded.