| What is WiFi? It is possible to form a | | | | emitted into the environment in a hotspot are |
| somewhat informed opinion on the safety or | | | | well below recommended levels and there is no |
| potential risks of this new technology | | | | evidence of any risk to humans. Yet some |
| without actually being a physicist yourself. | | | | people blame WiFi exposure for everything |
| Quite simply, Wi-Fi is the wireless | | | | from sleep disturbances, headaches and |
| technology most commonly used to connect | | | | blurred vision, to heart and breathing |
| people to the Internet in schools, coffee | | | | problems. |
| shops, hotels and other network locations, or | | | | |
| to connect cell phone users to one another. | | | | Because no study has ever shown a conclusive |
| Wi-Fi is certainly convenient for travelers | | | | risk to human health from exposure to these |
| and students, but is it dangerous? Many | | | | low-frequency radio transmissions, many |
| believe that the low-level electromagnetic | | | | simply shrug off the complaints of these |
| waves that radiate from the wireless Internet | | | | people, choosing to believe their symptoms |
| source to each individual user can be harmful | | | | are coincidental or caused by another source. |
| to your health, even causing cellular changes | | | | |
| and possibly cancer in some cases. | | | | So just how high are the levels of radiation |
| | | | in a hotspot? According to Dr. Michael Clark |
| The area covered by a WiFi Internet | | | | of the HPA, the published research on mobile |
| connection is known as a "hotspot"; this is | | | | phones and wireless networks does not |
| the area in which the waves radiate to give | | | | indicate a risk to human health. "All the |
| users access to the world wide web. It can | | | | expert reviews done here and abroad indicate |
| span several kilometers, although the waves | | | | that there is unlikely to be a health risk |
| cannot pass through treed areas. While in the | | | | from wireless networks" he says. "The few |
| hotspot, a laptop user can simply connect to | | | | studies on cellular phone masts that have |
| the network, access the Internet, and check | | | | appeared in peer-reviewed journals claiming |
| their Email or do their other business on the | | | | to observe health effects are not at all |
| run. | | | | conclusive. The real problem is deciding what |
| | | | level of precaution is appropriate. |
| A wireless network uses radio waves to send | | | | |
| communications across a two-way network. A | | | | "When we have conducted measurements in |
| computer's wireless adapter translates the | | | | schools, typical exposures from wifi are |
| Internet connection data into a radio wave | | | | around 20 millionths of the international |
| and sends it to the wireless router - the one | | | | guideline levels of exposure to radiation. As |
| in your laptop. This process works in reverse | | | | a comparison, a child on a mobile phone |
| as well, sending a radio signal back to the | | | | receives up to 50% of guideline levels. So a |
| host computer. | | | | year sitting in a classroom near a wireless |
| | | | network is roughly equivalent to 20 minutes |
| Hotspots Useful Stations or Environmental | | | | on a mobile. If wi-fi should be taken out of |
| Hazards? | | | | schools, then the mobile phone network should |
| | | | be shut down, too - and FM Radio and TV, as |
| Some report an unusual sensitivity to the | | | | the strength of their signals is similar to |
| waves emitted in these hotspots. Officially, | | | | that from wi-fi in classrooms. |
| the levels of WiFi electromagnetic radiation | | | | |