A single nocturnal exposure to 2-7 millitesla static magnetic fields does not inhibit the excretion of 6-sulfatoxymelatonin in healthy young men

Abstract

The present study sought to evaluate possible acute effects on 6-sulfatoxymelatonin (aMT6s) excretion, a surrogate for melatonin levels in blood, in volunteers exposed to static magnetic fields with flux densities representative for workers in light metal reduction plants and operators of medical MRI in hospitals. Eleven healthy male volunteers (23-43 years) participated. Urine samples were collected for two consecutive 24 h periods from 22:00 hours day 1 (exposure day) through day 2 (day after exposure) and then for 24 h from 07:00 hours on day 7 (control day). On the day of exposure the subjects slept in the MRI room from 22:00 hours until 07:00 hours next morning, thus receiving a 9 h exposure to the magnetic field (2-7 mT). On the day after exposure and on the control day, they slept at home and otherwise performed their ordinary daily activities. Total daily urine production was collected in four parts: 22:00-07:00 hours, 07:00-11:00 hours, 11:00-18:00 hours, 18:00-22:00 hours, and the volume for each interval was measured and recorded. Samples were transferred to coded bottles and frozen for later RIA analysis of aMT6s. Pairs of values of mean hourly aMT6s excretion, both diurnal and for the four daily intervals, were compared using two-sided Wilcoxon signed ranks test. The day of exposure and the day after exposure were not significantly different from the control day, either for the total diurnal secretion or the interval data. In summary, the study shows no association between a single nocturnal exposure to a static magnetic field of strength 2-7 mT and excretion of aMT6s in urine.

Magnetic Fields and Cancer: Epidemiology, Cellular Biology, and Theranostics

“…It is questionable whether chronic human exposure to MFs might affect melatonin secretion, its circadian rhythm, or both [77][78][79][80]. In general, no cumulative effects on melatonin secretion in humans have been found in response to MFs and this rebuts the "melatonin hypothesis" in which a decrease in plasma melatonin concentration (or a disruption in its secretion) would be correlated with the occurrence of breast cancers as a consequence of exposure to MFs [81][82][83][84][85][86][87][88]. Indeed, MF exposure correlates with an increased proliferative activity of the mammary epithelium, which is a likely explanation for the cocarcinogenic or tumor-promoting effects of MF exposure that is observed [89].…”

The effects of extremely low-frequency magnetic fields on melatonin and cortisol, two marker rhythms of the circadian system

“…2001 119 Hong et al, 2001 120 Levallois et al, 2001 121 Griefahn et al, 2002 122 Youngstedt et al, 2002 123 Kurokawa et al,…”

Electromagnetic Fields and Human Endocrine System

“…Although EMFinduced suppression on nocturnal melatonin secretion has been reported in occupational and residential studies [15,16,17,18,19,20], in the majority of laboratory-based exposure studies [21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39], EMF did not exert a distinct influence on melatonin or 6-hydroxymelatonin concentrations[see 40] (Table 1). According to Karasek et al [28,40], discrepancies in the results may depend on different experimental paradigms, including differences in certain characteristics of the applied magnetic fields, such as field induction, frequency, duration of exposure, timing of exposure, applied vector, etc.…”