Authors
Braune S, Wrocklage C, Raczek J, et al.

The authors studied the effect of a RF electromagnetic field on the nervous system control of blood pressure. Ten young adults were sham-exposed to a phone model fixed to the right side of the head for 35 minutes, and then exposed to EMF at 900 MHz, pulse frequency 217 Hz, simulating a GSM phone system. At the end of each period of sham exposure or exposure, blood pressure was measured in the resting state, during standing for 60 seconds, and during a Valsalva manoeuvre, which causes changes in the lung pressures and in heart rate and blood pressure. Resting blood pressure was increased by 5-10 mm Hg after EMF exposure. The authors speculate that these changes were due to an increase in the sympathetic component of the autonomic nervous system. There were no other significant differences between the exposure and sham periods.

The main shortcoming of this study was the lack of randomization in the sequence of sham-exposure and exposure. The sham exposure was always done first.