Effects of electromagnetic fields (electrosmog) on sleep and cognitive performance
The Institute of Pharmacology and Toxicology at the University of Zurich demonstrated in 2007 that certain adverse effects on brain physiology are dependent on the dose of electromagnetic radiation to which one is exposed.
The study
Fifteen healthy boys, recruited from students at the Universities of Zurich and ETH, participated in the study. In three sessions placed at one-week intervals, the 15 participants slept for two nights in a controlled environment. The first night served as an adaptation, and on the second night, the experiment was conducted [1].
Before sleeping, the 15 participants were subjected for 30 minutes to 3 different intensities of electromagnetic radiation through an antenna placed near their left cerebral hemisphere.
The three different intensities of electromagnetic radiation to which the boys were exposed are:
- zero exposure (sham control)
- 0.2 W/Kg exposure
- 5 W/Kg exposure
Among the 15 students, 13 reported having a cell phone and using it less than one hour per day. Participants were instructed not to consume caffeine and alcohol for the three days preceding the study nights. In addition, phone calls were prohibited during the day of the experiment.
During the exposure period (including sham control), participants performed cognitive tasks, and relative performance was measured.
The values 0.2 W/Kg and 5 W/Kg represent the specific absorption rate (SAR) of radiation. In Switzerland, the limits are 2 W/Kg for an exposure in a home/public/urban environment and 10 W/Kg for an exposure during a work occupation. The intensity in the first case (0.2 W/Kg) was therefore very weak and in the second case (5 W/Kg) very strong but still below the national limits for exposure during the working period. To make a comparison with concrete examples, below you find the specific absorption rates (SAR) of some phones. These values are measured during a call when the phone is placed close to the ear [2].
| Smartphone | SAR (W/Kg) |
|---|---|
| Motorola Edge | 1.79 |
| Axon 11 5G | 1.59 |
| OnePlus 6T | 1.55 |
| Oppo Reno 5G | 1.37 |
| Apple IPhone 13 | 0.98 |
| Samsung Galaxy Note20 5G | 0.684 |
The results
Sleep latency, i.e., the time interval between turning off the lights and reaching sleep stage 2, increased in proportion to the intensity of electromagnetic radiation.
This shows that exposure to non-ionized electromagnetic radiation causes adverse health effects and that higher radiation intensities cause more severe health effects.
For cognitive tasks, only one of the three tests reported significant results. The speed of execution in the 1-back task decreased significantly with increasing EMF intensity.
The authors of the study conclude:
These long-lasting changes in the non-REM sleep EEG provide further evidence for a non-thermal effect of RF EMF up to 5 W kg -1 in humans as a thermal effect is not likely to last for several hours after termination of exposure.
In other words, the effects on the non-REM phase of sleep caused by only 30 minutes of EMF exposure provide further evidence for a nonthermal effect of EMF on humans. Thus negating the widespread assumption that only ionizing radiation (x-rays, microwaves, etc.) cause adverse effects on humans.
For more details I suggest you read for yourself the scientific study discussed in this article. Find the link in the bibliographic citations below.