Does using headphones / earphones plugged into a cellphone for taking calls / listening to music pose a significant health risk in the long run in terms of radiation exposure?
Also it depends what your headphones are connected to. If they are connected to your cell phone and you are taking calls using a wired headset your exposure could be significant. A conventional headset uses a wire cable. Wire has metal in it. This metal conducts the radiation coming from your cell phone allowing it to travel up the wire and into your head.
What about just listening to music on your cell phone. If the music is downloaded onto your phone this is safer. But if you are streaming, then again your EMF exposures could be significant.
Based on Konrad's comment, a link to the Bioinitiative Report: http://www.bioinitiative.org/table-of-contents/ The relevant sections appears to be Section6, Section9, Section10, Section11 and Section13 (I still need to read through these, will quote sections out of these as I work through them)
CONCLUSIONS: Our results showed no evidence of any association between ELF-MF exposure (100 µT at 50 Hz) and AD, and ELF-MF exposure does not influence the pathogenesis of AD induced by Al overload.