Wireless Computer Networks (WiFi - wLANs & WiMAX)

WiFi systems such as wireless networked systems (wLANs) used in schools, offices and in many homes can emit significant amounts of radiofrequency (RF) radiation.

WiMAX systems are being rolled out in town and city centres, airports, railway stations, shopping malls, universities and colleges, etc. to allow people to have access to the Internet wherever they are.

The most obvious difference between the two systems is the range. While WiFi is in the hundreds of metres, WiMAX is theoretically designed for up to 30 miles! However, this is only a theoretical range, and it is expected for most base stations to have a range of between 4 and 10 miles. To achieve such ranges, the power levels have to be much higher.

Typical levels measured in a classroom are reproduced graphically here (left). Even when a WiFi enabled piece of equipment is not actively being used, while it is switched on it will be contacting the WiFi node regularly to retain a good connection. The control node transmits a pulsing signal continuously to synchronise the system and set the timing for communication with the equipment.

Sir William Stewart, who chaired the Stewart report 2000 (updated in 2005) expressed his concern in the Panorama programme screened in May 2007 about the potential adverse health effects that pulsing RF radiation might have, especially on the nation's children.

The effects of exposure to RF radiation are being increasingly widely reported. These are summarised (with extensive references) in the articles "Radiofrequency EMFs and Health Risks" available free to Powerwatch subscribers, as is a more technical article on wLANs, and more information about the expansion of wireless networks in "Mobile Phone Masts and Wireless Computing"

To find out whether you are exposed to microwave (RF) radiation, you can hire our easy-to-use monitors, which come complete with instructions about use and interpretation of findings. The COM monitor was featured on the Panorama programme.

To hear the pulsing of the signal from the microwave source, you can buy an Electrosmog Detector,	or you can hire an A-COM.	To measure the signal strength of the microwave radiation, you can hire or buy a COM.

If you are unsure which of the hire instruments you want, (the COM or the A-COM) click here. If you want to find out more about the Electrosmog Detector, click here.

Cordless (DECT) Phones

Digital Cordless Telephones (DECT) are increasingly becoming the first choice of phone apparatus used in the home and workplace. These telephones use the same technology as mobile phones and emit RF radiation 24 hours a day, whether the phone is in use or not. Many people who are sensitive to RF radiation can feel ill-health symptoms (headaches, nausea, heart palpitations, sleep disturbances, blood pressure changes, etc.) in a house with this type of phone. Powerwatch subscribers have access to more detailed articles on DECT phones, electrical hypersensitivity, etc.

For a safer alternative to a standard DECT cordless phone - a Low Radiation version, please click here.

For more information about the screening products available from EMFields, click here.