The field strength from modile phone handsets is orders of magnitude greater than that from WiFi, as it has to be detectable at the cell station which may be several Km away.

Credible studies so far of the effects mobile phone field strengths have shown no problems: http://www.global-engineering-excellence.org/en/engineering_news/news_universities/08_2006/06_08_01_radiation.html;jsessionid=743870BAC06220FD996AD15C8858B907

so we can expect WiFi to be harmless.

TV and radio aren't relevant, unless you are close to the transmitter- and even there, apart from apocryphal stories about hearing voices detected by fillings, over 80 years of experience has shown nothing harmful. You really have to sit on the antenna to be hurt.