Biologists have found out what effect radio waves have on fish embryos. It turned out that they do not significantly affect the mortality rate, morphology, and response to light, but slightly suppress sensorimotor functions. How this will affect adults remains to be seen.
For the experiment, a group of scientists from the University of Oregon placed in a chamber built from a Faraday cage, zebrafish, and popular aquarium fish. An antenna and a transmitter were attached to the camera, which emitted 3.5 GHz radio waves (it is used for 4G and 5G networks). So that laboratory conditions did not affect the development of embryos, scientists monitored the temperature (28-29 degrees Celsius) and the water level (at least five millimeters above the eggs) in the tank. The results are published in the journal PLOS ONE.
From the sixth hour after fertilization, the samples were exposed to waves for 42 hours. Three more days they were studied for possible changes. The analysis showed that there was no significant effect on mortality and morphology. Irradiation did not affect the ability of the samples to respond to light in either the light or dark phase. But a moderate inhibition of the fright reaction was found, which indicates some sensorimotor disorders. According to the authors, this can serve as an early marker of disorders of the neuromuscular system, which will manifest themselves in adults.
The results are very different from those shown by the previous study. According to him, the impact on the embryos of aquarium fish with radio waves with a frequency of 100 MHz leads to a delay in development. This difference can be explained by the start time of the tests (in the old experiment, the effects of the waves began immediately after fertilization, and not after six hours), since in the early stages of development, embryos are more sensitive, and the frequency of 100 MHz may have been significantly more biologically active than 3, 5 GHz.
The group used artificially high signal levels to more likely detect the effects of exposure. The radiofrequency exposure of 8.27 W / kg is about 200 times greater than what a person receives through a mobile phone and 100 times more than what we can get with general exposure to the population. The absence of large-scale effects, even with such a high signal level, shows that for people, exposure to 3.5 GHz is likely to be benign.
Scientists note that their findings are still incomplete. “It is possible that any effects of radio emission found in our study could be transient, and the embryos could recover or adapt to a static signal between the end of the exposure (48 hours after fertilization) and experimental measurements (120 hours after fertilization),” the authors say. In future studies, they are going to simulate mobile network signals with longer exposure and faster modulation of the wave frequency. In addition, the plans to study the effects of radio and other types of radiation or chemical stressors on embryonic physiology.