Apple Airpods - EMF radiation levels? Can anyone here do a quick measurement?

[Music1969]

Again, the amount of energy pumped out

But again (respectfully) as you said you are only looking at it from an engineering perspective and don’t have any qualifications in cell biology.

Interesting Sony includes the below in their manual for their Airpods Pro competitor (WF-1000XM3). Respectfully, Their language seems less certain than yours?

I think the consensus among qualified experts is more research is needed...

I agreed, I don’t think anybody needs to lose any sleep. Just a technical discussion, nothing more.

“The available scientific evidence does not show that any health problems are associated with using low power wireless devices. There is no proof, however, that these low power wireless devices are absolutely safe. Low power Wireless devices emit low levels of radio frequency energy (RF) in the microwave range while being used. Whereas high levels of RF can produce health effects (by heating tissue), exposure of low-level RF that does not produce heating effects causes no known adverse health effects. Many studies of low-level RF exposures have not found any biological effects. Some studies have suggested that some biological effects might occur, but such findings have not been confirmed by additional research.”

 

[Arpiben]

The power equivalence to an hour of AirPod use in a dark room is about 0.2 seconds in the Sun on a clear day.

Your sun power equivalence is not correct in terms of spectrum range considered (full Vs few MHz @2.4GHz )

Depending on solar activity, sun radiation at that frequency is around 70 SFU ( 10 000 SFU during sun bursts) at earth level.
SFU: Solar Flux Unit
SFU = 10-22 W m-2 Hz-1
Sun energy/radiation within 2.4GHz Bluetooth bandwidths is therefore negligible.

 

[Music1969]

While bluetooth headsets have been around for years, things took a step change last year in terms of units out in the wild with Apple’s AirPods specifically ..

All estimates I’ve seen are over 50 million units sold in 2019.

https://www.androidauthority.com/true-wireless-earbuds-market-1074986/

 

[nerdstrike]

But again (respectfully) as you said you are only looking at it from an engineering perspective and don’t have any qualifications in cell biology.

My experience of cell biologists is that they generally are more interested in reaction chains, processes and physical structures than physicochemical properties of specific molecules.

There is evidence that DNA will absorb some microwave energy, converting it particularly into rotational and torsional movements. However the extent to which microwaves will penetrate the outer layers of skin is much harder to quantify because so many molecules absorb microwaves differently. The Wikipedia page on microwave burns suggest 20% of 2.4GHz photons are absorbed in the first millimeters of skin. We might therefore infer that any risk is mainly confined to superficial tissues rather than the brain for example. We might also expect a blossoming of ear and cheek melanomas from the early years of mobile phones if there is indeed a meaningful risk. I think 40 years is enough to manifest such consequences...

Don't forget that DNA is stored in water, and spends most of its time in more robust storage arrangements (in humans at least), and exists in an environment full of repair mechanisms. Energy imparted mainly as movement is much easier to dissipate than shorter wavelength photons that can excite chemical bonds directly. That is why we must routinely be mindful of UV exposure, but hanging out near a hot skillet is not hazardous.

There has been extensive experimentation in the use of microwaves to accelerate chemical synthesis, but that is in the region of hundreds of watts (i.e. inside the microwave oven rather than outside). They wouldn't get much done at airpod powers...

 

[Koeitje]

Actually, I’d really like more people to be aware of this problem. EMF is not a joke like most people think. I used to have terrible headaches until I began wearing clothes made of emf fabrics. Actually, my doctor even thought I had brain cancer, but luckily I don’t have it. I think I’m just too sensitive to EMF, so that’s why I should wear special clothing to protect myself. As for Airpods, I’ve never had them, actually. I try to avoid wireless devices that work by Bluetooth only.

That sounds like a pretty useful placebo effect.

 

[Delrin]

Hi -

This is a really good question and I think videos like that serve as an interesting reminder that the world we live in is flooded with electromagnetic radiation at various frequencies - unless perhaps you live here.

I've worked with MRI systems for over two decades, and have a medical physics background that included courses on radiation biology. I've worked on the siting of ultra high-field MRI systems including the shielding aspects for the static magnetic field and faraday cages for electromagnetic radiation. I've also been involved in the design of MRI radio frequency transducers (coils) which deliberately transmit EMF into tissues and which are subject to regulatory limits on SAR (specific absorption rate).

The short answer to your question, in my view, is that there is no reason to doubt the measurements seen on YouTube as the measurement instruments (and EarPods) are doing what they are designed and marketed to do. You are wise to defer on the question of whether the measured emissions are safe, as it's impossible to prove that anything is totally safe (like it's impossible to prove that listening to classical music does not increase the risk for Alzheimer's disease by some infinitesimally small amount).

The longer answer (that you didn't ask for but I'll give anyway): I can add my perspective on how this is addressed in the medical device context. For radiofrequency (RF) fields, we are only required to consider the "specific absorption rate" or SAR, which is ultimately a determinant of the potential for heating of the tissues. The hypothetical concern is that a critically ill patient could experience thermal stress if the whole-body energy deposition is too high, or that in extreme cases local tissue injury could result from "hot spots" in the body.

To first approximation, you can imagine the human head as a bucket of salty water. Exposing this to the alternating electric field of an RF waveform will induce currents in this conductive medium, which is subject to Joule heating like any other conductor. Depending on the magnetic field, the transmitted RF may excite standing waves within the tissue exactly like the room modes we struggle with in audio/acoustics. This is an issue with newer 7 tesla systems, whose operating wavelength is comparable to the diameter of the human head. This can cause RF hot spots that are problematic in the same way that room modes create spurious peaks and nulls.

We use CST EM simulation software to model the energy deposition, and also perform tests using "phantom" heads made of materials to simulate human tissue. There are also software and hardware safety features on an MRI scanner to monitor losses in the RF chain. The limits are quite conservative, and a scan can be automatically interrupted if the cumulative power deposition exceeds a threshold (the scan is allowed to start based on "look ahead" software checks, but this can be overridden by hardware monitoring of the actual power deposition).

So all this is well and good, and you can be sure that Apple did careful SAR modelling through both simulations and experiment before marketing their EarPods or whatever. You will note that all of this is aimed at controlling tissue heating, and there is no consideration of other biological effects. That is because, according to the scientific consensus presented to policy makers, there is no evidence of other biological risks. Still, good engineering practice dictates that exposures be kept "as low as reasonably achievable" even if there is no demonstrable risk.

In the radiation biology courses I took (20 years ago), which covered things like cancer radiotherapy and risks from accidental exposure to ionizing radiation, the risks from non-ionizing EMF were considered to be negligible from a health perspective.

Interestingly, anyone who has worked with high-field MRI systems will have experienced first hand a direct biological effect associated with strong magnetic fields. If you move through the "fringe fields" of a strong MRI scanner (eg 3 tesla or even more so at 7 tesla) the magnetic field gradient has an effect on the inner ear. This can cause a strong feeling of vertigo and even nausea. For this reason, makers of 7 tesla MRI scanners restrict the speed at which the "patient table" is automatically transported into the magnet bore. This is very specific to the particular spatial field gradients of a very high static magnetic field, and personally I have never experienced anything similar from 60Hz line or RF frequencies (nor would I expect to).

Before someone else points this out, there is of course a difference in the level of acceptable risk associated with a "medically necessary" procedure versus recreational ear buds. However, the principles and regulatory frameworks are very similar.

Btw I could do a quick measurement with equipment in our lab, but (a) I don't have earbuds and (b) I don't doubt that the emission levels would be similar to those reported on YouTube.

 

[kemmler3D]

There is no proof, however, that these low power wireless devices are absolutely safe.

You can't prove a negative. You can't prove that anything is absolutely safe, especially when the copy is reviewed by a legal department.

The rest of the paragraph points out that studies that seem to cause problems haven't been replicated.

While some meta-analyses have shown a link to cancer, the mechanism (if there really is one) is clearly not well understood.

 

[Delrin]

Agreed Music1969 - the best you can do, with the frequentist statistics that are almost universally used in this type of research, is to say one of the following:

1. We detected a statistically significant effect, according to some specified probability threshold; or
2. No significant effect was detected, according to a specified probability threshold, meaning there might have been an effect but it was below the minimum detectable effect size for the statistical power of the study and the specified threshold.

Otherwise stated, absence of evidence is not evidence of absence. Of course the best tutorial on the topic is this (viewer discretion advised due to some salty language):

 

[Beave]

That sounds like a pretty useful placebo effect.

What it really sounds like is spam (in other words, that post is spam, so please delete your response).