Having had two acquaintances diagnosed over the past couple of years with brain tumors in the area where they hold their cellphones, I'm not so sure there isn't something to this.
When I was in radio, we were instructed to limit our exposure when taking transmitter readings. Now people have miniature transmitters stuck to their heads, sometimes hours a day.
There is, however, a huge reason for downplaying and poohpoohing the possibility of a cell phone-tumor connection, namely the biggest class-action lawsuit in the history of the world.
Four year old children were developing cataracts, basically going blind at four. The cause of the cataracts? They were watching food cook in microwaves, shoving their heads right up against the door and watching. In spite of the fact that there are screens built into the door to catch the microwaves, some escaped and caused the cataracts. Yes. I could believe that microwaves from cell phones cause tumors.
Ah, don't you miss it! Was it an Optimod? (I was in radio for 20 years).