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.
1. Basics of wi-fi
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 Public Health England (PHE) position regarding such exposure.
2. General position
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.
As part of this approach, the Health Protection Agency (now PHE) carried out a systematic programme of research into wireless networks and their use in schools, including measurements of exposures from networks. The project has now been completed and its results support PHE’s view that exposures from wi-fi are small in relation to the ICNIRP guidelines and in relation to exposures from mobile phones.
The results of the wi-fi project were provided to the Advisory Group on Non-ionising Radiation and taken into account in its 2012 comprehensive review of the scientific evidence.
3. Key points
There is no consistent evidence to date that exposure to RF signals from wi-fi and WLANs adversely affect the health of the general population.
The signals from wi-fi are very low power, typically 0.1 watt (100 milliwatts), in both the computer and the mast (or router) and resulting exposures should be well within internationally-accepted guidelines.
The frequencies used are broadly the same as those from other RF applications.
Based on current knowledge, RF exposures from wi-fi are likely to be lower than those from mobile phones.
On the basis of current scientific information, exposures from wi-fi equipment satisfy international guidelines. There is no consistent evidence of health effects from RF exposures below guideline levels and no reason why schools and others should not use wi-fi equipment.