University of California, Irvine June 2008
EH&S; Radiation Safety Division
WHAT IS WI-FI AND IS IT SAFE?
Wi-Fi is an acronym for “wireless fidelity” and it refers to a wireless network for computers that uses
radiofrequency radiation for communication just like cell phones and two-way radios (walkie-talkies) do.
Communication across a Wi-Fi network is very similar to two-way radio communication:
1. A computer's wireless adapter translates data into a radiofrequency signal and transmits the data using an antenna to a nearby wireless router.
2. The wireless router receives the signal and decodes it. It sends the information to the Internet using a wired Ethernet connection. The Ethernet is a widely-used local area network (LAN) technology, with a local area network referring to a wireless computer network covering a small geographic area such as a home, an office, or a school.
3. The process also works in reverse, with the router receiving information from the Internet, translating it into a radiofrequency signal, and then sending it via an antenna to the computer’s wireless adapter.
Since Wi-Fi systems emit high-frequency electromagnetic radiation (at either 2.4 GHz or 5 GHz, with a GHz [gigahertz] being a frequency of one billion cycles per second), some concern has been raised regarding the safety of using a Wi-Fi system.
But these systems generally emit at a very low power -- typically about 0.1 Watt emitted from both the computer antenna and the router antenna. The power falls off very rapidly beyond a few inches from the antennas. In comparison, cell phones emit between 0.6 Watts and 3 Watts (typically at about 1 Watt), generally at 1.9 GHz.
There is a good deal of controversy nowadays about potential health effects caused by Wi-Fi radiation. Currently, it is believed by most scientists that Wi-Fi radiation exposure is safe for most people with the possible exception being small children exposed for long periods of time.
Although no health effects in children have been identified, it is recommended that children not sit for hours daily with a Wi-Fi laptop on their laps; placing the computers on a table is much better. The same thing goes for cell phone use by children -- use is acceptable, but spending hours a day on a cell phone is discouraged as a precautionary measure even though definitive health effects have not been observed in studies.
Of course, the exposure to Wi-Fi radiation is somewhat additive if a person is in a room full of others on WiFi. But since the radiation intensity drops off so rapidly with distance from the Wi-Fi emitting source (e.g., the laptop antennas), most of a user's exposure is from his/her own system unless other users are within a few feet away.
In conclusion, exposure to Wi-Fi radiation is presently considered to be very safe. Studies on possible health effects caused by long-term Wi-Fi (and cell phone) radiation exposure continue to be conducted. Some good websites for further reading regarding potential Wi-Fi radiation health effects are listed below:
BBC NEWS | Technology | Wi-fi health fears are 'unproven'
http://www.redherring.com/Home/3752
BBC NEWS | UK | Magazine | Wi-fi worry
Originally Posted by libido
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