Danger Especially With In-Ear Headphones
How Harmful is Bluetooth?
In addition to WLAN and the various mobile communications standards (LTE, 5G, 6G, etc.), Bluetooth in particular is used worldwide as a wireless standard. Class 2 Bluetooth, which is particularly common today, emits a transmission power of 2.5 milliwatts in the 2.4 gigahertz band and has a range of about 20 meters indoors. Class 3 industrial Bluetooth, on the other hand, emits 100 milliwatts with a range of about 100 m. This high value is also about 10 times weaker compared to the transmission power of WLAN 5 GHz. Nevertheless, the potential health effects of Bluetooth should not be underestimated.
The World Health Organization (WHO) and the International Agency for Research on Cancer classify high-frequency electromagnetic fields, which include Bluetooth, as “possibly carcinogenic” (Group 2B). Some studies suggest that Bluetooth radiation makes the blood-brain barrier holey, which could potentially have neurological effects. Other research points to possible non-thermal effects, such as oxidative stress or changes in electrical brain activity with long-term Bluetooth exposure.
Wireless Bluetooth earplugs in particular unnecessarily increase radiation exposure, as a study by the Environmental Health Trust found.1 Unnecessary because there is a real alternative: so-called Airtube headphones. The conversion of the electromagnetic frequency into audible sound does not take place in the earplugs themselves, but in the cable. It is then transmitted to the ear with slightly deteriorated sound quality, like a stethoscope. However, this technology not only reduces EMF exposure by 99.9 percent, it also prevents magnetic fields of up to 1,000 gauss from being generated in the ear (even with wired headphones).
With Bluetooth plugs, the Airpods also come into contact with each other via the so-called magnetic near-field induction NFMI, the resulting fields go directly through the brain. There seems to be no scientific research into what NFMI can do in the brain. By the way, wired headphones or headsets are not necessarily the best solution either. The cables can transmit cell phone radiation and even worsen the SAR value (specific absorption rate) compared to wireless technology.
Conclusion: Bluetooth is certainly not the biggest threat compared to WLAN and mobile radio. For Bluetooth headphones or earbuds, Airtube is available as an approximate replacement.
From an article in Raum&Zeit, Volume 43, Issue #257, Sept/Oct 2025
Translation & redaction by: Carolyn L. Winsor, P2P Consulting
© Copyright 2025, Raum&Zeit, Wolfratshausen, Germany
AI Digital and online translation assistance utilized.