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 a ll-night (23:00-07:00 hr) to 60-Hz magnetic fields at an intensity (resulta nt flux density = 28.3 microTesla [muT]) well within the occupational-expos ure range, or sham exposed under equivalent, counter-balanced, no-exposure (less than or equal to 0.2 muT) control conditions. Concentrations of melat onin, and the major metabolite of melatonin, 6-hydroxymelatonin-sulfate (6- OHMS), in first-void morning urine were not altered in either gender by exp osure to the magnetic field, compared to control conditions. Statistical an alysis also failed to reveal any evidence for exposure-related alterations in blood concentrations of multiple hematologic and immune system parameter s (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.