The article Electromagnetic Radiation Due to Cellular, Wi-Fi and Bluetooth Technologies: How Safe Are We? states that non-thermal effects of EMR such as wifi and Bluetooth are such that wireless devices like Bluetooth earphones should be completely avoided:
People should be made aware that the EMR from using day to day cellular, Wi-Fi and Bluetooth devices are harmful to human health. The levels of radiation observed in most cases such as phone calls, internet browsing on laptops and smart- phones, using wireless routers and hotspots, Bluetooth smart-watches and smartphones are unsafe when compared with radiations limits determined by medical bodies. According to the current medical literature, various adverse health effects from exposure to RF EMR have been well documented. For now, wireless technologies must be avoided as much as possible.
Is this over-exaggerated? I don't see how the risk of a mobile phone with wifi and a Bluetooth earpiece is evaluated, or if this damage is potentially permanent.
I found this one also stating that the ear part is most sensitive to radiation and that specifically earbuds are quite dangerous possibly. Although it is on the emf protection website.