Scientists probe laptops’ Wi-Fi emissions

15 September 2009

Scientists at the Health Protection Agency began a research project on wireless local area networks (WLAN) in late 2007.

One aspect of public concern over Wi-Fi is its use by children in schools. So as part of its study into the technology scientists set up 15 laptop computers commonly used in UK schools and investigated the strength of the radiowaves around them.

The team measured very small output powers even when the devices were transmitting continuously and found the powers would be lower still with the intermittent transmissions that occur in normal use. The effective powers in the direction of maximum emission were in the range 17 to 57 milliwatts (mW) and well within the 100 mW limit set for Europe.

The tests were carried out in a specially adapted laboratory at the HPA's Centre for Radiation, Chemicals and Environmental Hazards in Oxfordshire.

Dr Simon Mann, head of the Physical Dosimetry department at CRCE, today presented the team's findings at the HPA's annual conference at the University of Warwick.

He said: "Our findings are consistent with the HPA position that exposures to the radio waves from Wi-Fi equipment are expected to be well within internationally-accepted exposure guidelines and less than levels from mobile phones."

The research is continuing and the scientists are planning to make measurements of how the output power is affected by the software and the work being done on the computers. Computer modelling is also being carried out to learn more about how the radio waves are absorbed in the body.

Notes to editors

• 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 frequencies used are broadly the same as those from other RF applications such as FM radio, TV and 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.
• For more information please contact Matthew Pardo on 01235 822745, or Andrew Tristem on 01235 822876 in the CRCE press office. Dr Mann is available for interview.
  

Last reviewed: 15 September 2009