Their environmental impacts
Power transmission systems often have to pass over farms to bring power to consumers in load centers. Many studies have investigated the biological effects of electric and magnetic fields on plants and animals.
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Vegetation
The effects of magnetic and electric fields on plant life has been studied in the field, in greenhouses and in the laboratory. On the whole, the findings of these studies show that plant life is not affected by electric and magnetic fields, except for some drying out (browning) of leaves with pointed tips in very high electric fields. In addition, the quality of vegetables that grow under high-voltage lines is not affected.
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Bees
Transmission line rights-of-way are home to hundreds of indigenous bee species. Generally solitary, bees nest in the ground or in woody material, while bumblebees are social and commonly nest underground, in existing cavities. Transmission line rights-of-way do not pose any danger to bees or bumblebees.
Still, the electric field generated by high‑voltage lines can be a serious disturbance to honey bees (Apis mellifera) by inducing weak currents in their bodies through the discharge of small intermittent or continuous electric shocks when the bees come in contact with conductive objects such as the hive. These biological effects of the electric and magnetic fields (EMFs) impact the bees’ behavior. Experiments in the lab and under high-voltage lines have shown that EMFs and electric shocks within the hive affect the bees’ physiology, life expectancy and social habits, as well as honey production. That’s why it is prohibited to set up hives near transmission line rights‑of‑way.
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Livestock
A number of studies have been conducted to determine if electric and magnetic fields generated by high‑voltage lines can affect the health, productivity, fertility, reproduction or behavior of livestock. These included investigations, database analyses and extreme case studies and were carried out on cattle, pigs, sheep and horses. The findings of this research seem to indicate that no biological disorders can be attributed to livestock exposure to fields generated by high-voltage lines. No harmful effects on the health, productivity, fertility, reproduction or behavior of livestock exposed to electric and magnetic fields were observed.
Publications
Hydro‑Québec research publications from 1988 to 2020
Study on the biological effects of electric and magnetic fields in bees
Other studies across the globe on effects of electric and magnetic fields on livestock
Studies on the effects of electric and magnetic fields in livestock
- Progesterone concentrations during oestrous cycle of dairy cows exposed to electric and magnetic fields, 1998.
- Biological effects of electric and magnetic fields on productivity of dairy cows, 1996.
- Cortisol secretion and growth in ewe lambs chronically exposed to electric and magnetic fields of a 60 Hertz 500 kilovolt AC transmission line, 1995.
- Melatonin and puberty in female lambs exposed to EMF: A replicate study, 1995.
- Melatonin secretion and puberty in female lambs exposed to environmental electric and magnetic fields, 1993.
- Behaviour of cattle in pens exposed to 500 kV DC transmission lines, 1991.
- Effects of highvoltage direct-current transmission line on beef cattle production, 1990.
- Joint HVDC Agricultural Study: Final Project Report, 1988.
- Algers, B. et Hultgren, J. (1986). Effects of Long Term Exposure to a 400 kV, 50 Hz Transmission Line on Oestrous, Fertility and Diurnal Rhythm in Cows. Swedish University of Agricultural Sciences, Department of Animal Hygiene, Report no. 15, Skara, Sweden.
- Epidemiologic study of Holstein dairy cow performance and reproduction near a high voltage direct current powerline, 1986.
- Mahmoud, A. A. et Zimmerman, D. R. (1983). High voltage transmission and environmental effects. Right of Way, December pp. 15‑19.
- Hennichs, K. (1982). Cows exposed to 400 kV lines. Inventory and Fertility Study. Swedish University of Agricultural Sciences, Department of Animal Hygiene with Farrier's School, Report no. 7, Skara, Sweden.
- A Study of Farm Animals near 765 kV Transmission Lines, 1980.
- Williams, J. H. et Beiler, E. J. (1979). An Investigation of Dairy Farm Operations in Association with 765 kV Transmission in Ohio. Ohio Power Sitting Commission and Cleveland Electric Illuminating Company, Cleveland, Ohio.
- Busby, K., Driscoll, D. et Washbon, W. E. (1974). A Field Survey of Farmer Experience with 765 kV Transmission Lines. Agricultural Resources Commission State Campus, Albany, New York, p. 6.
- Ware, B. J. (1974). Effects of 765 kV Transmission Lines on Animal Grazing Habits. American Electric Power Service Corp. New York, 3 p.