title: Experimental investigation of possible warmth perception from a head exposure system for human provocation studies with TETRA handset-like signals.
abstract: An experimental investigation of warming and warmth perception caused by handset EMF exposure was performed in order to examine its possible impact on blinding. Healthy male participants (15) were exposed to three different exposure conditions: sham and Terrestrial Trunked Radio (TETRA) handsets with maximum 10 g averaged SAR values of 1.5 and 6 W/kg each on three days. The study followed a randomized, double-blind design. TETRA signals simulated exposure from a handheld device consisting of a 385 MHz carrier modulated with a pulse length of 14.17 ms and a pulse period of 56.67 ms (i.e., duty cycle 25%; 17.65 Hz pulse modulation). A body worn antenna was used and fixed at the left ear. In addition to subjective ratings, skin temperatures at two locations close to the radiating element of the body-worn antenna were measured. The measurements revealed a temperature rise proportional to the supplied RF power with an average temperature increase measured at the two locations of 0.8 °C following the high exposure level of 6 W/kg. However, subjects were not able to distinguish between exposure conditions based on their subjective perception and thus the double-blinding was ensured.
authors.affiliation: Competence Centre of Sleep Medicine, Charité-University Medicine Berlin, Berlin, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Dorn
authors.forename: Gernot
authors.initials: G
authors.lastname: Schmid
authors.forename: Torsten
authors.initials: T
authors.lastname: Eggert
authors.forename: Cornelia
authors.initials: C
authors.lastname: Sauter
authors.forename: Thomas
authors.initials: T
authors.lastname: Bolz
authors.forename: Heidi
authors.initials: H
authors.lastname: Danker-Hopfe
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D055615:Electrical Equipment and Supplies / Q000009:adverse effects; D004574:Electromagnetic Fields; D006257:Head / Q000528:radiation effects*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D010465:Perception / Q000528:radiation effects*; D011846:Radio Waves; D012881:Skin Temperature; D013697:Thermosensing / Q000528:radiation effects*; D013997:Time Factors; D055815:Young Adult
keywords: TETRA; blinding; double-blind; electromagnetic fields; heat perception