i found an article on the web that should expel all your fears
Dr. Michael Clark of the HPA (a UK health agency similar to the American CDC) said: "
a year sitting in a classroom near a wireless network is roughly equivalent to 20 minutes on a mobile. If Wi-Fi should be taken out of schools, then the mobile phone network should be shut down, too — and FM radio and TV, as the strength of their signals is similar to that from Wi-Fi in classrooms'
if you are still intersted in reading the whole articule , hit this link :
http://www.wi-fiplanet.com/news/article.php/3653711