Encyclopedia Home / E / Electromagnetic Fields (EMF) - HealthCentral Encyclopedia

Electromagnetic Fields (EMF)

  • Definition

    All electric currents produce two kinds of fields - electric and magnetic - but their effects are different. Electric fields are easily blocked by metal or other shielding, but magnetic fields penetrate most materials and so are more likely to reach the human body.


    From the time you slap the snooze button on your alarm clock to the time you click off the bedside lamp at the end of the day, you are bombarded by invisible electric and magnetic fields. These fields are everywhere; they emanate from household appliances and cellular phones, from the high-voltage power lines strung outside your home, and from deep within the earth itself.

    All electric currents produce two kinds of fields: electric and magnetic. Scientists do not know how electromagnetic energy actually affects cells and tissues in plants, animals or people. Scientists say that the strength of electromagnetic energy most people are exposed to is low when compared to other forms of radiation, particularly the kind produced by radioactive materials. Nuclear radiation can rip through cells with the power of a cannon ball striking plate glass, sometimes causing cancer. Electromagnetic energy produced by electrical equipment is much less powerful, striking the same glass window with the force of a flea.

    All electrical devices produce some form of electric, magnetic or electromagnetic fields, but not all at the same frequency (a measure of how rapidly fields change with time). Each frequency may be distinct in terms of potential effect. A partial biological response or effect may result from exposures to one frequency but not others. In other words, one cannot assume that an effect or problem seen on one region of the electromagnetic spectrum will occur in some other region.

    It is well known that overexposure to x-rays and ultraviolet radiation, both very high in the spectrum, pose health risks by breaking chemical bonds in cellular molecules. Current research indicates that EMF fields are unable to break such bonds.

    A recent study stated that on the basis of a review of all available childhood brain cancer studies, there was no support for an overall association between EMF and childhood brain cancer. Another study concluded that although there is much debate and controversy surrounding the effects of low intensity electromagnetic fields and radiation, there is no convincing evidence to suggest that exposure to the fields commonly encountered in the environment will cause any significant adverse health effect in humans.

    With regard to users of mobile telephones, current evidence fails to support the existence of well-defined bioeffects from exposure to radio-frequency radiation.


    Are there any proven risks to EMF exposure?

    What about during pregnancy? and for infants?