Saturday, 5 March 2011
Cell Phone Radiation and EMF Protection
Electricity is simply the flow of electrons. This can occur over a high power transmission line or through wiring in the home or office. Whenever electricity passes through a wire two fields of force are created. One is an electrical field and the other is a magnetic field. In the United States electrical current reverses direction 60 times each second and thus is called alternating current, or AC. The cycles of current are measured in a unit called Hertz (Hz) so named for the German physicist Heinrich Hertz. Hertz is simply defined as the number of cycles per second. Electrical current in the U.S. operates at 60 Hz while electricity in most other parts of the world operates at 50 Hz. Most electric power in the U.S. is of an extremely low frequency, i.e., under 3000 Hz. As frequencies increase, the distance between one wave and the next becomes shorter and shorter. Consequently, there is a greater amount of energy generated in the field. Shorter wavelengths mean greater energy. Electrical fields can be shielded rather easily by using metallic barriers. However, magnetic fields, such as those in the 60 Hz range, will easily penetrate through most any barrier and become very difficult, if not impossible, to shield. It's important to understand the term Hertz (Hz) since it is used commonly to express the frequencies of appliances and devices like cell phones and microwave ovens. Megahertz (MHz) is one million hertz and gigahertz (GHz) is one billion hertz or one billion cycles per second. Most cell phones operate in the frequency range of 800 to 2200 megahertz. To make a comparison, the human heart being dependent upon electrical function, beats in a frequency of 2 Hz, or two cycles per second. Most electrical activity of the human body operates in the hertz range.
Another important term is gauss, or milligauss (mG). This unit measures the intensity of the magnetic field. It was so named for the German astronomer and mathematician Karl Gauss. A milligauss is one one-thousandth of one gauss. As an example, the earth has a natural magnetic field that has been measured to be about 0.5 gauss. Since humans have been exposed to the earth's natural magnetic field from the beginning of their existence this natural magnetic field is not harmful to the human body. However, power lines, electrical appliances, electrical wiring, cell phones, etc. all give off magnetic fields that are not natural to mankind. The intensity of these fields is expressed through the term milligauss. Abnormalities in embryos can be produced from magnetic fields as little as one milligauss. (11) Studies have shown a 500% increase in the risk of childhood leukemia, lymphomas and brain tumors in children exposed to power lines generating an electromagnetic field of only four milligauss. (12) Most scientists believe we should be exposed to no more than 1 mG. Small handheld meters called gaussmeters can be purchased inexpensively to measure the electromagnetic field in the home and office. However, the gaussmeter only measures the intensity of the magnetic field. It does not measure the wireless signal or information-carrying radio wave.
Hertz measures frequency and milligauss measures intensity. Keep those terms in mind as you read information about devices such as cell phones and common household appliances.