Melatonin metabolite levels in workers exposed to 60-Hz magnetic fields: work in substations and with 3-phase conductors.
Melatonin suppression by 50/60-Hz magnetic fields represents a plausible biological mechanism for explaining increased health risks in workers. Personal exposure to magnetic fields and ambient light, and excretion of the melatonin metabolite 6-hydroxymelatonin sulfate (6-OHMS), were measured over 3 consecutive workdays in electric utility workers. There was a magnetic field-dependent reduction in adjusted mean nocturnal and post-work 6-OHMS levels among men working more than 2 hours per day in substation and 3-phase environments and no effect among those working 2 hours or less. No changes were observed among men working in 1-phase environments. The results suggest that circular or elliptical magnetic field polarization, or another factor linked to substations and 3-phase electricity, is associated with magnetic field induced melatonin suppression in humans.
Burch
J B
JB
Department of Environmental Health, Colorado State University, Fort Collins 80523, USA. jbburch@cvmbs.colostate.edu
Reif
J S
JS
Noonan
C W
CW
Yost
M G
MG
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm; D004560:Electricity; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004784:Environmental Monitoring; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000528:radiation effects* / Q000652:urine; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D011210:Power Plants; D011829:Radiation Dosage; D018570:Risk Assessment; D017132:Workplace
D008550:Melatonin; C012365:6-hydroxymelatonin