2000,and is estimated to reach approximately 13 million by the year 2006.However,the rapid development and widespread use of cellular telephones have raised questions about the safety of exposure to radio frequency (RF) energy from these devices.Reports of dizziness,headaches,fatigue,"tingling ears" and other symptoms have the public concerned.These concerns have been reflected in alarming media reports that link the long-term use of cellular telephones to adverse health effects such as brain cancer.