Medical/biological study (observational study)

Magnetic fields and the melatonin hypothesis: a study of workers chronically exposed to 50-Hz magnetic fields med./bio.

By: Touitou Y, Lambrozo J, Camus F, Charbuy H

Published in: Am J Physiol Regul Integr Comp Physiol 2003; 284 (6): R1529-R1535

Aim of study (acc. to author)

To investigate the potential effect of occupational and residential exposure to 50 Hz magnetic fields on the secretion of melatonin in men.

Background/further details

Thirty male subjects participated in the study. Out of these, 15 were exposed to 50 Hz magnetic fields during worktime (in electrical substation) and free-time (living near the substation). The other 15 subjects had non-technical jobs and were subjected only to the normal electric and magnetic fields of daily environment.
Occurring magnetic fields were measured for each subject for one week with a wearable measurement device during normal activities. To determine the melatonin level in blood, subjects stayed in a hospital for one night. A catheter was inserted to collect blood samples hourly without waking. Additionally urine was collected to determine the 6-sulphatoxy melatonin level.

Endpoint

endocrine changes: melatonin secretion

Exposure

- 50/60 Hz
- magnetic field
- electrical substation
- occupational
- residential

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: 1 - 20 years exposed subjects	magnetic flux density: 2.6 µT mean magnetic flux density: 0.1 µT mean magnetic flux density: 0.64 µT mean (arithmetic mean of daytime) magnetic flux density: 0.82 µT mean (arithmetic mean of nighttime) magnetic flux density: 0.72 µT mean (arithmetic mean)
Exposure 2: 50 Hz control subjects	magnetic flux density: 0.092 µT mean magnetic flux density: 0.004 µT mean magnetic flux density: 0.04 µT mean (arithmetic mean of daytime) magnetic flux density: 0.04 µT mean (arithmetic mean of nighttime) magnetic flux density: 0.04 µT mean (arithmetic mean)

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Exposure duration	1 - 20 years
Additional info	exposed subjects

Exposure setup

Exposure source	occupational and residential exposure (electrical substation)

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	2.6 µT	mean	measured	-	-
magnetic flux density	0.1 µT	mean	measured	-	-
magnetic flux density	0.64 µT	mean	measured	-	arithmetic mean of daytime
magnetic flux density	0.82 µT	mean	measured	-	arithmetic mean of nighttime
magnetic flux density	0.72 µT	mean	measured	-	arithmetic mean

Exposure 2

Main characteristics

Frequency	50 Hz
Type	magnetic field
Additional info	control subjects

Exposure setup

Exposure source	everyday exposure

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	0.092 µT	mean	measured	-	-
magnetic flux density	0.004 µT	mean	measured	-	-
magnetic flux density	0.04 µT	mean	measured	-	arithmetic mean of daytime
magnetic flux density	0.04 µT	mean	measured	-	arithmetic mean of nighttime
magnetic flux density	0.04 µT	mean	measured	-	arithmetic mean

Exposed system:

human
whole body

Methods Endpoint/measurement parameters/methodology

endocrine changes: blood level of melatonin, urinary level of 6-sulphatoxy melatonin (RIA assay)

Investigated system:

blood, urine
investigation on living organism

Investigated organ system:

endocrine system

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

No significant differences in the melatonin level as well as in the 6-sulphatoxy melatonin level were found between exposed subjects and the control group.
The authors conclude that occupational and residential exposure to 50 Hz magnetic fields do not lead to alterations in the melatonin secretion.

Study character:

medical/biological study
observational study
full/main study
blind study

Study funded by

not stated/no funding

Touitou Y et al. (2022): Assessment of cortisol secretory pattern in workers chronically exposed to ELF-EMF generated by high voltage transmission lines and substations
Burch JB et al. (2008): Geomagnetic activity and human melatonin metabolite excretion
Davis S et al. (2006): Effects of 60-Hz magnetic field exposure on nocturnal 6-sulfatoxymelatonin, estrogens, luteinizing hormone, and follicle-stimulating hormone in healthy reproductive-age women: results of a crossover trial
Gobba F et al. (2006): No association between occupational exposure to ELF magnetic field and urinary 6-sulfatoximelatonin in workers
Ichinose TY et al. (2004): Immune markers and ornithine decarboxylase activity among electric utility workers
Youngstedt SD et al. (2002): No association of 6-sulfatoxymelatonin with in-bed 60-Hz magnetic field exposure or illumination level among older adults
Noonan CW et al. (2002): Relationship between amyloid beta protein and melatonin metabolite in a study of electric utility workers

Magnetic fields and the melatonin hypothesis: a study of workers chronically exposed to 50-Hz magnetic fields med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Exposure 2

Main characteristics

Exposure setup

Parameters

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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