Study type: Medical/biological study (observational study)

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. med./bio.

Published in: Ann Epidemiol 2006; 16 (8): 622-631

Aim of study (acc. to author)

To study whether exposure to a 60 Hz magnetic field under controlled conditions is associated with a decrease in urinary nocturnal 6-sulphatoxy melatonin level and increase in luteinizing hormone, follicle stimulating hormone, and estrogen levels in healthy premenopausal women (aged 20 to 45 years; n=132).

Background/further details

It has been suggested that exposure to residential magnetic fields can disrupt the normal nocturnal increase in melatonin levels resulting in increased risk for breast cancer.
Half the participants were assigned to magnetic field exposure for 5 consecutive nights during the early to midluteal phase of the menstrual cycle. The next month, participants were sham exposed. The other half of subjects were assigned the reverse order of exposure.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 60 Hz
Exposure duration: 5 consecutive nights

Exposure 1

Main characteristics
Frequency 60 Hz
Type
Waveform
Exposure duration 5 consecutive nights
Exposure setup
Exposure source
  • charging base of electrical toothbrush positioned underneath the bed of the testperson
Setup The height of the appliance underneath the test person's bed was adjusted until the magnetic field at the pillow was 0.5 - 1 µT greater than the ambient magnetic field level without the device turned on.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 µT maximum measured - -
magnetic flux density 0.5 µT minimum measured - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Magnetic field exposure (magnetic fields greater than ambient levels in the home) was associated with decreased 6-sulphatoxy melatonin levels, but no changes in reproductive hormone levels were found. Increasing age, medication use, and increasing BMI were associated with decrased nocturnal 6-sulphatoxy melatonin levels.
The results provide further evidence that exposure to magnetic fields is associated with decreased nocturnal melatonin levels, but do not support the hypothesis that such exposure results in increased urinary levels of estrogens, luteinizing hormone, or follicle stimulating hormone. Thus, if magnetic field exposure contributes to the risk for developing breast cancer through actions of melatonin, data of this investigation do not support the hypothesis that such risk is caused in part by corresponding increased levels of urinary estrogens, luteinizing hormone, and follicle stimulating hormone.

Study character:

Study funded by

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