All-night exposure to EMF does not alter urinary melatonin, 6-OHMS or immune measures in older men and women

Healthy men (n = 22) and women (n = 24), 40-60 years of age, were exposed all-night (23:00-07:00 hr) to 60-Hz magnetic fields at an intensity (resultant flux density = 28.3 microTesla [microT]) well within the occupational-exposure range, or sham exposed under equivalent, counter-balanced, no-exposure ( < or = 0.2 microT) control conditions. Concentrations of melatonin, and the major metabolite of melatonin, 6-hydroxymelatonin-sulfate (6-OHMS), in first-void morning urine were not altered in either gender by exposure to the magnetic field, compared to control conditions. Statistical analysis also failed to reveal any evidence for exposure-related alterations in blood concentrations of multiple hematologic and immune system parameters (CD3, CD4, CD8, natural killer [NK] cells). The present results replicate and extend earlier negative findings based on the exposure of young men to power-frequency magnetic fields.