Does evening exposure to mobile phone radiation affect subsequent melatonin production?
OBJECTIVE
To test whether exposure to the emissions from a digital mobile phone handset prior to sleep alters the secretion of melatonin.


METHODS
In a double-blind cross-over design, 55 adult volunteers were both actively exposed or sham-exposed (in random order on successive Sunday nights) to mobile phone emissions for 30 min (0.25 W average power). Urine collection occurred immediately prior to retiring to bed and on rising the next morning. Melatonin output was estimated from principal metabolite concentrations (6-sulphatoxymelatonin (aMT6s) via radioimmunoassay), urine volumes and creatinine concentrations.


RESULTS
Total melatonin metabolite output (concentration x urine volume) was unchanged between the two exposure conditions (active 14.1+/-1.1 microg; sham 14.6+/-1.3 microg). The pre- and post-bedtime outputs considered separately were also not significantly different, although the pre-bedtime value was less for active versus sham exposure. When melatonin metabolite output was estimated from the ratio of aMT6s to creatinine concentrations, the pre-bedtime value was significantly less (p = 0.037) for active compared to sham. Examination of individual responses is suggestive of a small group of 'responders'.


CONCLUSIONS
Total nighttime melatonin output is unchanged by mobile phone handset emissions, but there could be an effect on melatonin onset time.
Wood
Andrew W
AW
Brain Sciences Institute, Swinburne University of Technology, Hawthorn, Victoria, Australia. awood@swin.edu.au
Loughran
Sarah P
SP
Stough
Con
C
D000293:Adolescent; D000328:Adult; D001315:Australia / Q000453:epidemiology; D040421:Cell Phone / Q000706:statistics & numerical data*; D002940:Circadian Rhythm / Q000528:radiation effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000652:urine*; D008872:Microwaves; D008875:Middle Aged; D011829:Radiation Dosage
D008550:Melatonin