To study whether exposure to radiofrequency electromagnetic fields from mobile phones would result in more headache or discomfort than sham exposure and to test possible effects on physiological parameters such as heart rate and blood pressure.
Seventeen subjects took part in a double-blind, randomized provocation study with cross-over design. Sixty-five pairs of sham and mobile phone RF exposures were applied. Each subject was allowed to take part in a maximum of four randomized pairs of trials, at least 2 days apart, among which, the RF session came first twice. A test session lasted almost 2 h, allowing for an adaptation and rest period.
|Exposure duration||continuous for 30 min|
|Duty cycle||12.5 %|
|Repetition frequency||217 Hz|
|Distance between exposed object and exposure source||8.5 cm|
|Chamber||The exposure system was the same as in [Wilen et al., 2006]. The exposure equipment, except for the antennas, was placed in a control room next to the shielded exposure room. The subjects were comfortably seated while looking at videos showing nature and wildlife films.|
|Setup||Two wall-mounted base station antennas [Huber et al., 2003] were mounted symmetrically at 8.5 cm from the sides of the subject's head, the movements of which were restricted sideways by wooden bars.|
|Sham exposure||A sham exposure was conducted.|
|Additional info||A power divider directed a part of the signal to one of the antennas or to an ohmic load (sham exposure) and another part to a power meter. The exposure was given on the subject's preferred side or selected by chance.|