UK: C2000 veroorzaakt gezondheidssymptomen maar is er niet verantwoordelijk voor. (!)
donderdag, 30 december 2010 - Categorie: Onderzoeken
De school van Rubin c.s. blijkt steeds maar weer meester te zijn in het zaaien van wetenschappelijke verwarring, al dan niet gesponsord door Big Telecom:
Bron: Occupational and Environmental Medicine 23 sept. 2010
Can exposure to a terrestrial trunked radio (TETRA)-like signal cause symptoms? A randomised double-blind provocation study.
Nieto-Hernandez R, Williams J, Cleare AJ, Landau S, Wessely S, Rubin GJ.
King's College London, Department of Psychological Medicine, Institute of Psychiatry, London, UK.
Objectives Concerns have been raised about possible health effects from radiofrequency fields pulsing at around 16?Hz. A radio system used by UK police (TETRA) employs signals which pulse at 17.6?Hz.
We tested whether exposure to a continuous wave signal at 385.25?MHz or a TETRA-like signal resulted in symptoms among users reporting sensitivity to TETRA compared to users not reporting sensitivity to TETRA.
60 sensitive and 60 non-sensitive users were exposed to three 50?min conditions: a signal with a 16?Hz component, a continuous wave condition and a sham condition. The mean radiated power for the 16?Hz and continuous wave conditions was 250?mW. The order of conditions was randomised and testing was conducted double-blind. Participants reported the severity of eight symptoms during and after each exposure, their mood state at the end of each exposure, and whether they could tell which sessions involved active signals. The study was registered in advance with the ISRCTN register.
Exposure to the continuous wave signal increased ratings of headache in all participants, fatigue in non-sensitive participants and difficulty concentrating in sensitive participants. Paradoxically, it reduced sensations of itching in sensitive participants. These effects were not observed in the condition with 16?Hz pulsing, except for those relating to concentration. Adjusting for multiple comparisons removed most significant effects, but not those relating to itch.
The results suggested that exposure to TETRA signals is not responsible for symptoms reported by some users, although exposure to a continuous wave signal may affect symptoms. Clinical trial number ISRCTN 73321766.
Voor het originele abstract zie:
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