Bluetooth headset & cellphone warning.

Bluetooth is getting popular. It is very convenient. No doubt about that part.

It might be no problem to use bluetooth keybord or mouse etc. But not headset. It is too close to your brain.

Bluetooth is used radio frequency as 2.4GHz. Microwave is about 10GHz. So it is almost same as you have small microwave on your ear.

Higher frequency is more destructive energy. You can think about infrared ray (IR) &  ultraviolet ray (UV) light. IR is lower frequency of human eye can see. UV is opposit side (high frequency). IR warm up body. UV destroy skin tissue.

Usually it is OK as you are far away. Because it decrease the energy and power are be inversely proportional to the square of the distance. Which means if you make double space, the power decreses 1/8.

That's why bluetooth headset on your ear all the time might be not good idea.

I did not have cellphone 10 years ago. We don't know yet about long time effect. But 2 of my friends got brain surgery in last 2 years.

So I'd recommend to use wired headset.It is your choice.

-Naoki