The closer to a power tower, the fewer flowers. And that has to do with the bees being stressed by the tower’s electromagnetic field. This was observed by a group of Chilean entomologists who conducted a series of experiments in poppy fields and in the laboratory. The scientists found that exposure to electromagnetic fields altered the expression of bee genes related to stress and behavior. The result was that the plants near the towers produced fewer seeds, affecting their survival. This could be the case along the entire length of the lineage and with other insects important for pollination.
The California poppy (Eschscholzia californica) is an invasive plant native to this region of the United States and Mexico. But the beauty of its orange flowers has made it an ornamental plant and it is grown in various areas with a Mediterranean climate. There are also those who have found medicinal uses for it. The poppy needs bees to pollinate its flowers. These insects use a sophisticated navigation system, aided by magnetic receivers, to find the flower fields and return to the hive. But the electromagnetic fields of the high-voltage pylons could impair this ability and short-circuit an interaction that is fundamental to both nature and agriculture.
After Marco Molina, director of the Center for Integrative Ecology at the University of Talca (Chile), and a group of Chilean and Argentine researchers observed that the flowering of plants around the high-voltage towers was lower, they wanted to see what happened. They suspected a connection between electricity, plants and bees. To study this, they focused on several California poppy fields (long ago naturalized in Chilean areas) in the city of Quinamavida. To compare the possible effects of electromagnetic fields, they located several high-voltage pylons, some of which were out of order. “One of the experimental complexities is evaluating the tower effect; That is, how the presence of a metal structure with hundreds of meters of cable affects visits from pollinators,” Molina points out. Therefore, they studied the behavior of insects in areas with active and inactive towers.
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As detailed in the journal Science Advances, they measured the range and intensity of the electromagnetic field around the towers at various distances (10, 25, 20 and 200 meters and more). Near the inactive poles, the electromagnetic field did not reach 1.5 microtesla (the tesla is a unit of measurement for electromagnetism). Meanwhile, the intensity at 10 meters from an active tower was 9.47 microtesla, dropped by half at 50 meters and was negligible from 200 meters.
Bees use the earth’s electromagnetic field for their navigation, so there is a possibility that artificial electromagnetic fields disturb the natural field. To find out, they analyzed honey bees (Apis mellifera) visiting the different fields. They found that those who foraged closest to the active crows produced an excess of a protein called HsP70. “We chose HsP70 because it has a widely observed functional role in insects and is activated by stressors; Therefore, it acts as a molecular marker for a state of environmental stress,” explains Molina. This stress manifests itself on a physiological level in an increase in temperature and in changes in the behavior of the animal.
To measure the magnitude of these disturbances, the scientists conducted a series of experiments in the lab, exposing several bees to a solenoid, a coil that creates its own electromagnetic field when an electric current is passed through it. After exposing them to a field of the same intensity measured near the towers, they studied the expression of 14 genes related to the immune system or navigation. In 12 of them they observed differences in expression between exposed and non-exposed bees. Regarding the HsP70 protein, the expression was 52% higher in the former than in the latter.
The final part of the study focused on observing the effects on pollination. The bees go where there are more flowers, regardless of whether there are high voltage towers. But where they were present, the frequency of visiting the nearest flowers (within 25 meters) was 308% lower than in the fields where there was no active tower. The reduction rate is limited to 16% if the flowers are more than 200 meters from the operating towers.
A long-term negative effect
“But the bees don’t avoid these areas, and that’s the problem.” “Even for very short periods of time, exposure to the electromagnetic field produces negative physiological effects that affect pollination,” says Molina. The end result was that there were fewer California poppies and fewer flowers around the towers. Below them is the stalk that hides the seeds, so the plant’s reproduction is compromised.
Although the scientists carried out their work close to the towers, they are confident that the effects will be reproduced throughout the high-voltage line, as this would show that the towers, some metal structures 20 meters high, were not affected by the error when the power plug is pulled. Finally, although new studies are needed, Molina asserts that EMFs not only affect bees, but also “other pollinators that live in the area, including bumblebees, butterflies and beetles.”
In 2019, Adam Vanbergen, a scientist at the French Research Institute for Agriculture, Food and Environment, led an investigation into what science knows about the effects of various types of electromagnetic radiation on pollinating insects, from visible light to that emitted by mobile phones. “In the visible spectrum, there was increasing evidence that artificial light at night can alter pollinator communities and potentially affect plant pollination,” says Vanbergen. However, he adds: “At that time there was no evidence, either through field research or through sound scientific studies, for a clear impact of the non-visible part of the spectrum of man-made electromagnetic radiation.”
Therefore, Vanbergen appreciates this work of Chilean scientists. “It appears to be solidly engineered and has a good mix of laboratory evidence of physiological effects and field evidence of disrupting insect foraging and plant pollination,” he says. This French pollination ecology expert highlights the use of active and inactive towers to base the observed effects on electromagnetic radiation rather than other sources. Regarding the impact on other species, Vanbergen recalls that the honey bee “is a very social bee, with a strong ability to orient itself in the landscape and may be more sensitive to this disturbance than pollinating insects, so it would be necessary to Be careful not to transfer it to other ways.
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