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EMF Study
(Database last updated on Mar 6, 2021)

ID Number 163
Study Type Human / Provocation
Model 6.1-21.8 MHz (FM) broadcasting tower exposure to residents of Schwarzenburg Switzerland and analysis of sleep disturbances and melatonin

Human subjects living near a shortwave radio transmitter in Schwarzenburg, Switzerland (built in 1939, broadcasting 6.1 - 21.8 MHz, with a maximum power of 2 x 150 kW) were given a health interview survey. In addition, two longitudinal studies were performed and some subjects were monitored for urinary secretion of 6-hydroxy-melatonin-sulfate. While no substantial increase of any chronic disease could be associated with exposure level, various health complaints such as nervousness, restlessness, insomnia, general weakness and tiredness, and limb pains were more frequent in the vicinity of the transmitter. Among the complaints, sleep interruptions were associated with E-field strength of the transmitter (an effect confirmed in multiple sub-studies). Morning excretion of 6-hydroxy-melatonin-sulfate was not related to the electromagnetic field strength of the transmitter or to sleep disorders. A related study of melatonin levels in nearby cow saliva also did not show an association. Although the number of school children at a highly exposed school within the study boundary was too small for conclusive interpretation, the accumulated promotion rate from primary to secondary grades there since the nineteen fifties was found to be lower than in a control school. In a subsequent study performed around the same transmitter, Altpeter et al (2006) reported on a second set of volunteers (n = 54) separated into low and high exposure groups and exposed by the tower for 1 week, followed by 1 week of no exposure immediately after the tower was permanently decommissioned. Consistent with the study initial 1995 study, the authors report better sleep quality, decreased tiredness, and increased melatonin levels following deactivation of the tower, especially in poor sleepers. It was difficult to perform the study in a completely blinded manner, and this may have introduced some level of bias. Alternatively, the authors suggest such individuals may be more acutely sensitive to RF fields. A subsequent report (2006) by SAEFL entitled "Electrosmog in the Environment" was provided to supply information and counter speculation and fear in the general public.

Findings Effects
Status Completed Without Publication
Principal Investigator Swiss Dept. Environ., Forests & Landscape
Funding Agency Swiss Telecom, SAEFL, Switzerland, Nat'l Res Prog, Switzerland (SNSF, NRP57)
  • Altpeter, ES et al. Bioelectromagnetics, (2006) 27:142-150
  • Altpeter, ES et al. University of Berne, Inst. for Social & Preventive Medicine, Study No. 55, (1995) :-
  • Comments

    The authors admit that the 2006 study was not conducted in a completely blinded manner, which may have affected the outcome. The blindedness of the initial (1995) study might also be an issue, since only poor sleepers were found to have a correlation with RF exposure levels. In the studies, volunteers recorded their own sleep quality in diaries and isolated their own saliva samples 5x per day and stored them in their refrigerator for daily pickup and melatonin analysis. Also, tower shutdown occured on the same day as the clock change from winter to daylight saving time, which may have also affected melatonin levels and sleep quality.