To evaluate the relationship between cellular telephone use and excretion of the melatonin metabolite 6-hydroxymelatoninsulfate in two populations of male electric utility workers (Study 1, n=149; Study 2, n=77).
Exposure duration: total daily exposure of 1-10, 11-25, or >25 min/day for 3 days
Exposure duration: not specified
No parameters are specified for this exposure.
|Exposure duration||not specified|
No change in 6-hydroxymelatoninsulfate (6-OHMS) excretion was found among those with daily cellular telephone use for more than 25 min in study 1 (5 worker-days). Study 2 workers with more than 25 min cellular telephone use per day (13 worker-days) had lower mean nocturnal 6-OHMS concentrations and overnight 6-OHMS excretion compared with those without cellular telephone use. There was also a linear trend of decreasing mean nocturnal 6-OHMS/creatinine concentrations and overnight 6-OHMS excretion across categories of increasing cellular telephone use.
A combined effect of cellular telephone use and occupational 60-Hz magnetic field exposure in reducing 6-OHMS excretion was also revealed in Study 2.
Conclusion: Exposure-related reductions in 6-OHMS excretion were found in Study 2, where daily cellular telephone use of more than 25 min was more prevalent. Prolonged use of mobile phones may lead to reduced melatonin production, and elevated 60 Hz magnetic field exposures may potentiate the effect.