No effects of pulsed radio frequency electromagnetic fields on melatonin, cortisol, and selected markers of the immune system in man

There is growing public concern that radio frequency electromagnetic fields may have adverse biological effects. In the present study eight healthy ma le students were tested to see whether or not radio frequency electromagnet ic fields as used in modern digital wireless telecommunication (GSM standar d) have noticeable effects on salivary melatonin, cortisol, neopterin, and immunoglobulin A (sIgA) levels during and several hours after exposure. In a specifically designed, shielded experimental chamber, the circularly pola rized electromagnetic field applied was transmitted by an antenna positione d 10 cm behind the head of upright sitting test persons. The carrier freque ncy of 900 MHz was pulsed with 217 Hz (average power flux density 1 W/m(2)) . In double blind trials, each test person underwent a total of 20 randomly allotted 4 hour periods of exposure and sham exposure, equally distributed at day and night. The results obtained show that the salivary concentratio ns of melatonin, cortisol, neopterin and sIgA did not differ significantly between exposure and sham exposure. (C) 2001 Wiley-Liss, Inc.