Is this man risking his health by using his phone? Would a Bluetooth headset make him safer – or more at risk?The surprising news last week that the California Department of Public Health has been suppressing its findings about the dangers of cell phone radiation for seven years caused several readers to sensibly ‘join the dots’ and ask the related question – ‘If cell phones really are dangerous, what about Bluetooth?’.
One reader wondered about the safety of her Apple Watch, which she wears on her wrist for most of most days. Another reader wondered about the safety of his Bluetooth headset, located on his head and potentially sending radiation directly into his ear and into his brain.
There are actually three types of radio transmissions to consider – cellular, Bluetooth, and Wi-Fi too. A modern smart phone is capable of transmitting on all three bands. Most of the time, people focus only on cellular transmissions, but probably, if you look around you, you are surrounded by many more Wi-Fi devices than Bluetooth or cellular devices – we should not overlook Wi-Fi from our considerations.
I just counted, and reached an astonishing total of almost 20 devices that are transmitting Wi-Fi signals in my house. As we keep adding more ‘smart home’ devices and ‘internet of things’ gadgets, we’re steadily adding still more to all the radio frequency energy that is invisibly filling our homes, offices, and indeed, the ‘great outdoors’ all around us, too.
Frequencies and Power
Bluetooth and Wi-Fi both use the same frequencies, around the 2.4 GHz range (some Wi-Fi may use 5 GHz too, but this is, if anything, worse not better).
The standard 2.4 GHz used is almost the same frequency as used by your microwave oven (2.45 GHz) which makes for an interesting thought – imagine wearing a microwave oven – without the shielding – on your person. How safe does that sound?
Okay, to be fair, microwave ovens typically radiate 600 – 1200 W of power, cell phones are about 1000 times less powerful. But, on the other hand, we have our cell phones with us for many hours a day, and simplistically, doesn’t 1000 minutes of exposure at 1 W sort of equate to 1 minute of exposure at 1000 W? In case you need a refresher on what microwaves can do, why not stick an egg in your microwave oven and cook it for a minute. Then cook a second one at one tenth power for ten minutes, if you think an extended exposure at lower power is okay.
Cell phones use a bunch of frequencies, and these days, as frequencies seem to keep climbing higher and higher, some are very close to the same 2.4 GHz frequency, others are lower, and a few go as low as around 750 MHz. Lower frequencies are generally better than higher frequencies, but to continue our microwave oven comparison, large commercial microwave ovens often operate at 915 MHz, a frequency very close to many cell phone frequency bands.
If we simply look at power outputs as a measure of the degree to which we should be concerned about the safety of our radio wave emitting devices, here are the numbers to consider :
Modern cell phones : From 125 mW up to 2 W – this varies automatically and depends on how close and good a connection the phone has to the nearby tower it is connected to. All the more reason to hope for good quality signals.
Wi-Fi devices : Device specific, and sometimes with power variations depending on connection quality too. From 30 mW up to 500 mW.
Bluetooth devices : There are three levels of Bluetooth power, described as Class 1, 2 and 3. Class 3, with the shortest range, has the lowest power – 1 mW. Class 2 is 2.5 mW. Class 1 is 100 mW.
So, your headset is probably 100 times less powerful than your phone. If your watch only uses Bluetooth, it too is very weak, and also probably does not transmit for much of the time when it is in passive/sleep mode. But if your smart watch has Wi-Fi, or if it has its own SIM and operates as a separate cell phone too, then you will be increasing its level of transmitting power.
Summary and More Info
Whatever the dangers of cell phone ‘radiation’ may be, it seems fair to say that the dangers are 10 to 100 times less from each Bluetooth and Wi-Fi device. On the other hand, if you’ve 20 Wi-Fi devices, and they’re being used more of each day than your phone, then the Wi-Fi radio energy in your environment is probably comparable to the cell phone radio energy too.
Note that we put quotes around the word ‘radiation’ directly above. If you’d like to know why, and if you’d like to better understand what may actually be the dangers associated with it, please now visit the second part of this article, Radio ‘radiation’ Explained.
Has the incidence of brain cancer been rising? There was a bump when CAT scanners were introduced, but that was a matter of better detection. We’re seeing a rise in automobile accidents that some are attributing to increased cell phone use, but we haven’t been seeing a rise in brain cancer even though older phones actually used higher power levels and had longer transmission times. (Higher frequencies and digital compression mean higher data rates and shorter packet times.)
There have been a lot of studies of the link between cell phones and brain cancer, and now and then someone seems to massage the statistics and finds a link with brain cancer, but this result doesn’t seem to hold up in repeated studies. There were similar studies with exposure to 50 and 60 Hz electric fields which are common in households with electrical power, but the statistical results tend to vanish with more data, and more careful analysis. I wouldn’t start wearing a tin foil hat just yet.
Your power analogy only works so well. I have a home heating system that warms the place up to 70F. Imagine if I set that to 700F, I’d be roasted like a turkey. That’s wrong. I’d be cremated. That’s not an argument to heat the place in the winter.
Thanks for your thoughtful comments.
On the other hand, not everything you say is correct. We’re only transitioning away from stateful calls at present – with GSM/CDMA calls, the phone is essentially transmitting all the time the call is established. Not quite so much with digital, but it is certainly transmitting when you’re talking and I suspect some transmitting even when you’re “silent” so as to send ‘side tone’ back down the line to the other party.
I’m glad you concede that some studies suggest links between phone usage and cancer. One wonders if the ‘repeated studies’ include those funded by the wireless carriers.
As for the power analogy, it gets a bit pointless to say ‘my analogy is better than yours’ but I will say that arguing that a normal temperature for a long time can be equated to an elevated temperature for a short time is absolutely not what I was saying, but it is what you are suggesting with your 70°/700° comparison.
Besides which, we’re not talking about ambient temperatures. We’re talking about temperatures inside the brain. Big difference.
I’m not ready to remove my tin foil hat, not just yet….. 🙂
My Father has worn Wi-fi 2.4 ghz headphones for 25 years that I am sure, with full days use because he is a retire eary, canadian citizen as of 2017. This year 2017 he was operated on for Basal Cell Cancer behind the right ear and one month since treatment has been fine. So that is a pretty Staggering Risk , I beleive the Bluetooth Transmitter is Located Behind the users Ear. On the Right or left side , i am not sure. So if I again sumate that this same Cancer could have easily genetically transferred to a Inoperable type with the ease then thats too much of a Risk and a Country like the USA the largest Consumer and they dont have Health Insurance, to pay for the Operation so then that same cancer COULD BE DEATH BY BLUETOOTH. Basal Cell Carcinoma was the DIAGNOSIS. So to continue the Debate he doesnt blame Bluetooth and Continues Using them.