Electric and Magnetic Fields
Electric and Magnetic Fields (EMF) are found virtually everywhere electricity is used in our modern society. For example, EMF exists around household wiring, electrical appliances and transmission lines.
AltaLink recognizes that some people are concerned about EMF, and we treat those concerns very seriously. AltaLink provides information to people who have questions to keep them informed about the status of EMF research, as summarized by national and international health agencies, including Health Canada and the World Health Organization. AltaLink does not conduct health research but does take measurements of fields near its facilities.
After more than 30 years of research that includes thousands of studies and reviews by multiple agencies, none of these agencies have concluded that exposure to EMF from power lines is a demonstrated cause of any long-term adverse effects to human, plant or animal health, as long as induction effects are properly managed. They have not recommended that the general public take steps to limit their everyday exposure to EMF.
No EMF exposure guidelines have been established for power line EMF in Alberta, Canada or the United States because there is no conclusive scientific evidence that EMF adversely affects health. Instead, agencies like the International Commission for Non-Ionizing Radiation Protection and the Institute of Electrical and Electronics Engineershave developed exposure guidelines that protect workers and the general public from well-documented immediate biological effects (similar to shocks) that can result from direct exposure to fields above those typically found in living environments.
Based on the research and the conclusions of these agencies, AltaLink believes that the levels of EMF associated with its high voltage transmission facilities are not a risk to your health. If you have questions or concerns, please contact us, and we will provide more information.
Some questions and answers
Will my radio or television reception be affected by a transmission line?
TV reception problems are unlikely. If they happen, they can often be solved by either TV antenna change or relocation. We can’t do anything about poor reception you might have had before a line was built, but if you think you might be experiencing poor television reception as a result of a transmission line, please give us a call.
AM and CB radio reception can be affected, particularly when directly under any power line, and the amount of interference depends on the type of radio and antenna. AltaLink conducts measurements to ensure it complies with interference guidelines.
Will my cable or satellite television or wireless internet system be affected by a transmission line?
A transmission line should not cause reception problems for cable or satellite television or wireless internet systems. If your cable or satellite provider suggests that a transmission line is affecting service, AltaLink will investigate.
Will my GPS (Global Positioning System) receiver be affected by a transmission line?
Reception problems for mobile GPS receivers are unlikely. AltaLink staff use GPS receivers near all our existing transmission facilities and do not experience problems. Please contact us if you believe our power line is causing a problem with your GPS device.
Will my cardiac pacemaker be affected by the transmission line?
A number of sources of electric and magnetic fields have been reported to affect some cardiac pacemakers. Potential sources of interference can include cellular phones, CB radios, wireless computer links, microwave ovens, microwave signals, radio and TV transmitters, paging transmitters, welding equipment, generating plants, rail transportation and power lines.
Transmission line magnetic fields are generally too weak to affect such devices. Very high electric fields can interfere with some models of pacemakers, but trees, buildings, fences and vehicles provide effective shielding from the electric field. If you have a concern, AltaLink will assist you in getting the right information to help you determine if your device is immune to electrical interference from this and other sources. Most of these devices are designed to filter out electrical interference or revert to a safe mode of steady pacing if interference becomes too great.
How are nearby metal buildings and wire fences affected by a transmission line?
Electrical charges will not normally accumulate on buildings close to transmission lines because appropriate grounding already exists. AltaLink will help ensure that metal on buildings is properly grounded to avoid the build up of an electrical charge.
When AltaLink is constructing a new transmission line near a building or fence, we will ground them so they do not pose a shock problem. Upon request, we can also check or ground other nearby fences, including electric fences and other structures. Let us know if you are planning to put up a new building, fence or gate near an existing line, and we’ll advise you on how to ground them and ensure they won’t affect access to the right-of-way.
Will a transmission line generate noise?
Sometimes noise can be heard from high voltage lines, and can sound like a hum, and a popping, crackling or hissing sound. This noise is usually most noticeable under rainy or foggy conditions although noise from wind or rain may mask the noise generated by the line. AltaLink ensures its transmission lines comply with the noise guidelines set out by the Alberta Utilities Commission (AUC).
Is there a difference between Alternating Current (AC) and Direct Current (DC) lines?
An AC line operates at the power line frequency of 60 Hertz, meaning the direction of the current alternates 60 times per second. The current in a DC line continually flows in the same direction, similar to the current in a flashlight or an automobile battery.
There are many factors to be considered when comparing AC and DC transmission lines. Both types of facilities produce EMF, and other effects such as audible noise, induction and small amounts of radio and TV interference.
Visit AltaLink’s website for additional information about Electric and Magnetic Fields.
