http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/04/28/nesmog28.xml

http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/04/28/nesmog28.xml: "Under international guidelines the amount of energy absorbed into the body from such radio waves cannot exceed two watts per kilogram when averaged over any 10 grams of tissue. The maximum signal strength next to the router or computer transmitter is 0.1 watts and the power level falls off very rapidly beyond a few cms from the transmission points. However it is believed that a classroom containing 20 laptops and two routers could combine and be equivalent to the emission from a mobile phone."