Can i use Internet ,up to 12 hrs. via blue tooth by mobile phone?

i am using net 10-12 hrs. daily via blue tooth by using mobile phone,i afraid about my mobile phone.does it harmfull for my mobile phone or not?

Can i use Internet ,up to 12 hrs. via blue tooth by mobile phone?
No this should be fine. As long as you are using AC power most of the time so you don't keep power cycling your phone battery. You might have noticed that your battery casing gets warm, but that has never caused a problem for me.