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Electromagnetic fields

Electromagnetic fields (EMF) are invisible lines of force around electrical equipment, power cords and wires that carry electricity. EMF includes:

Electric fields

Electric fields are produced by voltage, such as when a hair dryer, coffee maker, fan or light plug is turned on. Increasing your distance from the source of the electric field will weaken the strength of the field. Electrical fields are also usually blocked or weakened by things that conduct (transmit) electricity, including trees, buildings and even human skin.

Magnetic fields

Magnetic fields are produced when current travels through wires or other electrical devices. For example, turning on a coffee maker creates a magnetic field. Like electric fields, increasing your distance from the source of the magnetic field weakens the strength of the field. Unlike electrical fields, magnetic fields pass through most materials, including trees, buildings and human skin.

  • How you’re exposed to electromagnetic fields

    Since most appliances are turned on briefly and then turned off, exposure to EMF is usually only for short periods of time. But power lines constantly produce magnetic fields. That is why most scientific research has looked at magnetic exposure from power lines, even though the magnetic field may be stronger around some appliances.

  • Exposure to EMF and cancer

    Magnetic fields are classified by the International Agency for Research on Cancer (IARC) as a possible cause of cancer, particularly for childhood leukemia. However, experts agree that there may be other explanations for the potential link between exposure to EMF and childhood leukemia. Find out more about how cancer-causing substances are classified.

    Over the past 25 years, there have been more than 100 studies published on the relationship between exposure to electromagnetic fields and cancer risk.

    Researchers haven’t found a conclusive relationship between exposure to EMF (at levels normally found at work, home or in the environment) and an increased risk of most cancers in adults or children. But there does appear to be a higher risk of childhood leukemia when EMF exposure is higher than levels normally found in the environment.

  • Tips to reduce your exposure

    Health Canada suggests that you don’t need to take any special care to protect yourself from EMF because there isn’t convincing evidence that the exposure in typical Canadian environments will cause any harm.

    If you are concerned about your exposure to EMF, you can increase the distance between yourself and the source of the electric and magnetic field. Here are some other things to think about:  

    • The strength of a magnetic field does not depend on how large, complex, powerful or noisy the appliance is. In fact, the magnetic fields near large appliances are often weaker than those near smaller appliances.
    • Until scientific evidence can clarify the link between exposure to magnetic fields from high-voltage power lines and cancer risk, you may not want your children to play directly beneath them for long periods of time.
    • Fix any household wiring problems or update household wiring in an older home since these might make electrical fields higher than normal.
  • Suggested links for more information

    General information about electromagnetic fields
    Learn more about sources of EMF exposure, potential health risks associated with exposure, and the role of government in monitoring scientific research regarding EMF in Canada and around the world.

    Health Canada – Electric and magnetic fields from power lines and electrical appliances
    CAREX Canada – Carcinogen profile: magnetic fields
    National Institute of Environmental Health Sciences (US) – Electric and magnetic fields
    National Cancer Institute (US) – Magnetic field exposure and cancer: questions and answers
    World Health Organization – Electromagnetic fields



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