Wi-Fi is the most popular technology used in wireless local area networks (WLANs). These are networks of devices and computers where communication occurs through radio waves instead of connecting cables.
Wi-Fi users can access and share data, applications, internet access or other network resources in the same way as with wired systems.
Wi-Fi devices must be equipped with antennas that transmit and receive radio waves in order to allow wireless connections. The devices operate in certain frequency bands near 2.4 and 5 gigahertz (GHz).
People using Wi-Fi, or those in the proximity of Wi-Fi equipment, are exposed to the radio signals it emits and some of the transmitted energy in the signals is absorbed in their bodies. This webpage sets out the PHE position regarding such exposure.
There is no consistent evidence to date that exposure to radio signals from Wi-Fi and WLANs adversely affects the health of the general population. The signals are very low power, typically 0.1 watt (100 milliwatts) in both the computer and the router (access point), and the results so far show exposures are well within the internationally-accepted guidelines from the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Based on current knowledge and experience, radio frequency (RF) exposures from Wi-Fi are likely to be lower than those from mobile phones. Also, the frequencies used in Wi-Fi are broadly the same as those from other RF applications such as FM radio, TV and mobile phones.
On the basis of the published studies and those carried out in-house, PHE sees no reason why Wi-Fi should not continue to be used in schools and in other places. However with any new technology a sensible precautionary approach, as happened with mobile phones, is to keep the situation under review so that parents and others can have as much reassurance as possible. That is why Sir William Stewart, former chairman of the Health Protection Agency (HPA), the predecessor of PHE, stated that it would be timely to carry out further studies as this new technology is rolled out. Based on this, the HPA announced on 12 October 2007 that it would be carrying out a systematic programme of research into WLANs and their use, to include measurements of exposures from Wi-Fi networks, in particular those in schools.
This project has now been completed. For further information please see the project page.