To study the potential effects of intermittent UMTS electromagnetic fields on blood circulation in the human head (auditory region) on two different timescales: short-term (effects occurring within 80 s) and medium-term (effects occurring within 80 s to 30 min).
16 healthy male subjects participated. Each subject encountered four different conditions on four different days at the same time of day: (i) SAR of 1.8 W/kg, (ii) SAR of 0.18 W/kg, (iii) sham exposure, and (iv) motor activation measurement (20 s finger tapping instead of exposure).
|Exposure duration||16 cycles: 20 s exposure (ON), 60 s recoveries (OFF)|
|Modulation type||cf. additional info|
|Setup||test person wore ear plugs; antenna fixed near to subject's ear|
|Sham exposure||A sham exposure was conducted.|
During exposure to 0.18 W/kg, a significant short-term increase (within 80 s) in oxy-heamoglobin and total haemoglobin was found, which was small (approximately 17%) compared to a functional brain activation (condition iv). A significant decrease in the medium-term response of deoxy-haemoglobin at 0.18 and 1.8 W/kg exposures was detected, which was in the range of physiological fluctuations. The medium-term heart rate was significantly higher at 1.8 W/kg than for sham exposure. The other parameters showed no significant effects.
The data suggest that intermittent exposure to UMTS electromagnetic field has small short- and medium-term effects on cerebral blood circulation and heart rate.