Wireless electronic devices and health
For mobile phones, see Mobile phone radiation and health
With the focus on health concerns of mobile phones, people are also beginning to question the health risks of other wireless devices now being increasingly used at work and in the home, such as wireless local area networks, wireless phones, Bluetooth devices, and so on.
According to the study currently being carried out by the World Health Organization (http://www.who.int/peh-emf/en/)
- "Electromagnetic fields of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All populations are now exposed to varying degrees of EMF, and the levels will continue to increase as technology advances. As part of its charter to protect public health and in response to public concern, the World Health Organization (WHO) established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz."
Wireless LAN
Although it is generally agreed that EMF levels for wireless LAN devices are much lower than mobile phones, there seems to exist less public understanding of the safety or otherwise of wireless LAN devices than there is for mobile phones. Many wireless LAN manufactures seem to indicate that they are operating towards specific predefined standards which are totally safe. Wireless LANs work by setting up microwave communication in the ranges of 2.4 to 5.7 GHz, depending on the technique that is used (WiFi, WiMax, OFDM, etc). The system is comprised by a base station (called access point, or AP) which establishes point-to-multipoint communication with a number of subscriber units or SUs, to which client computers are connected. Both devices are bidirectional and have antennas that emit at a certain RF power. By definition, the SU stands very near to the computer operator, and the communication link is constant, i.e., not only when there is a call, such as in a mobile phone. In small work and home environments, the AP is also usually very near to human beings, sometimes a few centimeters away. Therefore, the situation, in terms of safety standards, such as ICNIRP, may be surpassed and a higher danger to health may be posed, in relation to other mobile wireless techniques.
Bluetooth
Bluetooth uses also the microwave frequency spectrum in the range of 2.4 GHz to 2.4835 GHz. However, the radiated output power of Bluetooth devices is very low in spectrum and in time, so a possibility of posing risks to health is low, too. Bluetooth devices can operate continuously or sporadically (on demand), so total exposure to EMF radiation is very variable.
Other devices
Radiofrequency in the microwave and radio spectrum is used nowadays in an enormous number of practical devices for professional and home use, such as:
- Wireless phones, most of them operating in the 900 MHz range
- Remote control devices for opening gates, etc.
- Portable two-way radio communication devices, such as walkie-talkies
- Wireless security (alarm) systems
- Wireless security video cameras
- Radio links between buildings for data communication
In addition, electrical and electronic devices of all kinds emit some sort of EM fields around its working circuits, generated by oscillating currents. Humans are in daily contact with computers, video display monitors, TV screens, microwave ovens, fluorescent lamps, electric motors of several kinds (such as washing machines, water pumps, etc.) and many others. The total background power of EM fields in the microwave range only can vary from zero to more 3 milliwatts per m2 in some areas. From an environmental-health point of view, less than 0,1 microwatts per m2 are desirable but often sharply exceeded due to the presence of today's technologies. The long range effects of these EM fields on human and animal health are still underway, and most of the studies available are only short-term studies which have shown no effect. However, as longer-term studies become available, health effects may be possibly found.