Chronic Exposure to 50-HZ Magnetic fields or 900-MHz Electromagnetic fields Does not alter Nocturnal 6-Hydroxymelatonin Sulfate Secretion in CBNS Mice

Several studies have reported that electromagnetic fields suppress nocturnal melatonin production in animals. In this study we investigated whether chronic (over 17 months) exposure to vertical 50-Hz magnetic fields with regularly varying intensity (1.3,13, and 130μT; 24 h/day) affects nocturnal 6-hydroxymelatonin sulfate (6-OHMS) production in female CBNS mice. The effects of 900 MHz radiofrequency radiation (90 midday) were also studied, using either continuous radiation with a specific absorption rate (SAR) of 1.5 W/kg or pulsed radiation with a pulse repetition rate of 217 MHz and a SAR (average) of 0.35 W/kg. Twenty-four mice per group were kept in metabolic cages (three animals per cage) for two nights (from 7 PM to 7 AM) with a 1-week intewal, and urine was collected. Urinary concentration of 6-OHMS, the main metabolite of melatonin, was determined by radio-immunoassay. Neither the extremely low-frequency magnetic field nor the radiofrequency radiation affected excretion of 6–OHMS in nocturnal urine.