21 male subjects participated in the study. Each subject attended one continuous exposure session, one intermittent exposure session and one sham exposure session in the afternoon with 1-week intervals in between, respectively.
Blood and urine samples were collected after each exposure session from the evening to the next morning.
|Setup||coils were arranged in a "magnetic helmet": a cubic structure formed by six Helmholtz coils, 35 cm in diameter, distributed in the three orthogonal directions; generated field was uniform and parallel to the direction of the local geomagnetic field|
|Sham exposure||A sham exposure was conducted.|
No significant differences were found in either plasma melatonin and urine hydroxymelatoninsulfate levels between continuous exposure, intermittent exposure or sham exposure conditions. However, a tendency to smaller night-time urine hydroxymelatoninsulfate levels after continuous exposure compared to sham exposure was found, particularly in subjects with relatively low natural urine hydroxymelatoninsulfate levels.
The authors conclude that there are no indications for effects of a head exposure of human subjects to a 50 Hz magnetic field on plasma melatonin and urine hydroxymelatoninsulfate levels.