How Does A Cell Phone Work?
Cell phones operate across a network of cellular sites called base stations. When using a cellular phone, sound signals are transmitted in radio frequencies and microwave frequencies with transmitters very close to the user’s head. Cell phones use a distant base unit, a cell phone antenna, as a means to receive and send communications in a laser-like beam of radiation to and from the cell phone. If you are in a car and using a cell phone, the cell phone locks on to different antennas as the car moves. As the car nears a cell phone antenna in the same cell phone network, less radiofrequency radiation is required by the cell phone to receive and send signals to the antenna. But as the car moves away, the cell phone uses more radiofrequency radiation to seek the closest antenna. These phones transmit at frequencies in the microwave range of 800 and 1900 megahertz.
Both RF and ELF are concerns with using a cell phone. There is a near-field and far field plume of radiation emitted when a cell phone is in use. According to the book Radiation Rescue, the near field radiates about a foot from the antenna , with the most intense plume in a 7 inch diameter circle around the antenna. As the picture illustrates, when using a cell phone, radiofrequency radiation penetrates approximately 2 inches into the adult brain. More radiation is absorbed in the brains of children talking on a cell phone placed to their ears. The far field radiofrequency radiation passes through almost everything in its course to a receiver.
In addition, the switching battery pack on a cell phone creates very high levels of extremely low frequency electromagnetic fields (ELF).
PDAs such as Blackberries and iPhones produce higher levels than cell phones of extremely low frequency emissions because they use more energy from the battery. Energy increases during the sending and receiving email, large files, and photos . ELF on these PDAs have been recorded from 20 (milligauss) mG to 200 mG. |