Hello? Hello? Can you hear me now? Probably the most repeated sentences in the world of cell phones today. Good connections or bad connections. We’ve all had them at one time or another. Can you even remember the day when you answered the phone at home and actually had to sit in one place never moving farther that a couple of feet or you would pull the phone off the wall or off the table? Longer cords were invented so we could pace the floor a little farther away from the phone. Now you can use the phone, use up your “minutes” and throw it away! My, how far we’ve come! Let’s delve into the world of cell phones: how they work and how they have evolved in function and into our lifestyles.
Wireless telephones are hand-held phones with built-in antennas, often
called cell, mobile, or PCS phones. These phones are popular with callers
because they can be carried easily from place to place.
When you receive a call on your wireless telephone, the message travels through the telephone network until it reaches a base station close to your wireless phone. Then the base station sends out radio waves that are detected by a receiver in your telephone, where the signals are changed back into the sound of a voice. One might ask, how did the finite mind ever conceive the idea of sending voice waves through the air or sending images through the air and have them not crash mid-air? Better yet, not having the radio frequencies messed up by a bird or a Boeing 747? Sheer genius! Getting back to the facts. Radio waves are electromagnetic energy. Another form of electromagnetic energy is that found in light, gamma rays and x-ray. Radio waves come in different wavelengths (the distance covered by one cycle) and frequency is the amount of times a wave passes by a specific area within a second.
Radio frequency energy includes waves with frequencies ranging from about 3000 waves per second to 300 billion waves per second. Microwaves are a subset of radio waves that have frequencies ranging from around 300 million waves per second to three billion waves per second. Those who are most prolific in the use of radio waves are fire and police departments, emergency personnel, radio and television stations and those who use wireless phones, pagers, satellite stations. The average homeowner owns radio frequency appliances such as the microwave and the ever- popular cell phone. Very much in the minds of people since the creation of the microwave and the cell phone has been the safety factor. These are appliances that touch us literally and there is always that question of “if I use this appliance will it hurt me in any way”.
The biological effects of radio frequency energy should not be confused with the effects from other types of electromagnetic energy. Very high levels of electromagnetic energy, such as is found in X-rays and gamma rays can ionize biological tissues. Ionization is a process where electrons are stripped away from their normal locations in atoms and molecules. It can permanently damage biological tissues including DNA, the genetic material. Ionization only occurs with very high levels of electromagnetic energy such as X-rays and gamma rays. Often the term radiation is used when discussing ionizing radiation (such as that associated with nuclear power plants). The energy levels associated with radio frequency energy, including both radio waves and microwaves, are not great enough to cause the ionization of atoms and molecules. Therefore, radio frequency energy is a type of non-ionizing radiation. Other types of non-ionizing radiation include visible light, infrared radiation (heat) and other forms of electromagnetic radiation with relatively low frequencies. In the early days of microwave ovens and cardiac pacemakers, there was a real possibility that a leaky oven with a significant electromagnetic field being emitted could interfere with operation of a pacemaker with an unshielded lead," reads one typical bit of advice (Occupational Medicine Forum, Journal of Occupational Medicine, 1992). "Both problems have since been corrected." The U.S. standard for microwave ovens limits energy leakage to five millwatts per square centimeter at a distance of five centimeters, and cardiac pacemakers now have shielded leads.
The Federal Communications Commission and the Food and Drug Administration
each regulate wireless telephones. FCC ensures that all wireless phones
sold in the United States follow safety guidelines that limit radio frequency
energy. FDA monitors the health effects of wireless telephones. Each agency
has the authority to take action if a wireless phone produces hazardous
levels of radio frequency energy. According to a Reuters report, the Food
and Drug Administration (FDA) says it will review the health effects of
wireless phones after a recent analysis of research suggested long-term
use may be linked to a risk of brain cancer. Swedish researchers said
last month the use of cellular phones over a long period of time can raise
the risk of brain tumors. Their findings contradict a number of earlier
studies and are "difficult to interpret," the FDA said in comments
posted on its Web site.
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