I think perhaps placing any electronic device in your bedroom is bad. There was this hype on A Current Affairs about placing a television in your bedroom, or even a fridge, as some people do. There was also some news story about a truck driver getting cancer near his ear and blaming it on mobile phones.
But it's "A Current Affairs"... Can you even trust some of the "research" that they do?
Yeah it's 'pop(ular)-news' and a lot of those stories are just to stir things up. Plus it wasn't really a discussed issue in my physics classes.
A mobile phone would emit very low power microwave radiation and by using the phone occassionally you will be fine. Being near the radio towers would be a hazard, since the microwaves are much more intense.