Resting blood pressure increase during exposure to a radio-frequency electromagnetic field.

Braune S, Wrocklage C, Raczek J, Gailus T, Lucking CH,

Lancet 351(9119):1857-1858, 1998

A single-blind placebo-controlled study conducted on seven healthy men and three women volunteers aged between 26 and 36 years continuously measured blood pressure, heart rate, capillary perfusion, as well as subjective well-being in relation to mobile telephone electromagnetic fields (EMFs) (GSM 900 MHz, 2 watt, 217 Hz frame repetition rate).

The study subjects were unaware of when they were being exposed because the telephone was fixed in a typical position on the right-hand side of the head and operated by remote control with no sound. The exposure protocol involved phases with placebo and with EMF exposure of 35 minutes each with a fixed sequence to allow for effects that might persist after exposure.

The researchers found that even though the people subjectively noticed no differences in well-being, their resting blood pressure increased during exposure to the EMF: "We conclude that exposure of the right hemisphere to a radiofrequency EMF for 35 minutes causes an increase in sympathetic efferent activity with increases in resting blood pressure between 5 and 10 mm Hg, most likely due to more pronounced vasoconstriction."

CONCLUSION: Exposure of the right hemisphere to a radiofrequency EMF for 35 min causes in human subjects an increase in sympathetic efferent activity with increases the resting blood pressure between 5-10 mm Hg. The effect is likely caused by vasoconstriction.