Does evening exposure to mobile phone radiation affect subsequent melatonin production?

Int J Radiat Biol. 2006 Feb;82(2):69-76. doi: 10.1080/09553000600599775.


Purpose: To test whether exposure to the emissions from a digital mobile phone handset prior to sleep alters the secretion of melatonin.

Materials and 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.

Publication types

  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Australia / epidemiology
  • Cell Phone / statistics & numerical data*
  • Circadian Rhythm / radiation effects*
  • Cross-Over Studies
  • Double-Blind Method
  • Environmental Exposure / statistics & numerical data*
  • Female
  • Humans
  • Male
  • Melatonin / urine*
  • Microwaves*
  • Middle Aged
  • Radiation Dosage


  • Melatonin