“C57BL/6 mice were exposed to 835 MHz RF-EMF at a specific absorption rate (SAR) of 4.0 W/kg for 5 hours/day during 12 weeks.”
That’s a pretty high exposure?
That’s a pretty high exposure?
Briefly put: Sunburns can be dangerous, but nobody gets a sunburn wearing SPF 250. Even if this experimental result is 100% correct, it does not prove any risk to normal cell phone users.
(It would be interesting to look for effects in cell tower maintenance workers, and others who've generally received far higher intensities / doses.)
Working in an office with ten other people that has installed a cell phone tower will likely provide substantial EMF (2 orders of magnitude). 5G bands require much higher density tower placement due to the reduced effective range of mm wave. These all have overlap and are not being tested in any way after installation.
There's clearly an effect. The question becomes how much of an effect are we currently living with and what are the limits that should be adopted.
Yes, there is health & safety research that needs to be done here. This particular study (mega-dose, low n, mice) is part of that. It's easily repeated at other frequencies, to compare effects. My prior comment suggested looking at a human population already receiving far-higher does of cell phone EMF. If you wanted a small control group, there's Green Bank ( https://en.wikipedia.org/wiki/Green_Bank%2C_West_Virginia#Na... ).
Scaled up to an approximate human mass: 4 W/kg * 70kg = 280W.
Apparently an idling human burns very approximately about 80W ("basal metabolic rate").
For example, human eyeballs are really bad at it. Staring at a microwave that has been recklessly modified to run without door, or with a hole in the door, is most dangerous by turning the eye's inside which is similar to raw egg white into the cooked form: cooked egg white is unsuitable for a lens due to the very strong scattering from the coagulated proteins. I'm sure other temperature sensitive parts exist with poor cooling, as they're not naturally expected to be able to get dangerously hot without the surrounding tissue heating it.
The lack of thermal effects they mentioned where whole body temperature; while hard to actually measure, I'd suggest thinking of the temperature of the blood in the arterial venous heart half when it comes to potential overtemperature. Yes, if the body as a whole has cooling issues, this blood that is about to enter the lungs (after coming from all around the body) is going to be overly hot. But if the bottleneck is the lack of blood vessel density in e.g. the eyeball, this temperature issue won't show up when measuring in the heart.
The RF was probably too low power to produce readily measurable effects on temperature in the brain. I imagine that it could be a difficult piece of data to collect. However, you're undoubtedly correct that whole body temperature wouldn't be informative in such a study.
Makes sense, keeping some distance from running microwave ovens is a good policy. After an oven has been in service for some time what are the odds seals become leaky, etc. Probably not a great risk but no harm in minimizing one's exposure.
If the door mechanically seals properly like it's supposed to, all should be fine. If the mechanics make it not be as flush as it used to, get rid of it or measure the RF power at it's operating frequency near it while it's running, to check whether it still properly seals the RF.
> ... Whole body exposure was at a SAR value of 4.0 W/kg for 5 h daily for 12 weeks for six randomly allocated mice. The other six mice received sham treatment for 12 weeks. The sham treated control groups were kept under the identical environmental conditions and treated the same circular pattern as the RF-exposed groups without RF-EMF exposure. The sham-treated and RF-exposed mice could move freely in their cage....
So the exposure is definitely whole-body.
> In terms of a possible thermal effect, we confirmed that exposure to RF-EMF in our system could not affect mouse body temperature as shown in Fig. S2. … There are few reports resulting in thermal effect or thermal damage to anesthetized rats after magnetic field (MF) or RF exposure, respectively.
It was a worthwhile experiment, and the results aren't particularly surprising.
It's wrong to call it a mistake. It's not a mistake, it's a simplification. We understand that simplifications have limited explanatory power. That's the tradeoff--simplified models are easier to understand but less accurate. All models sacrifice some amount of accuracy.
Reducing the interaction between varying electromagnetic fields and the staggering dimensionality of health & living things to wattage is a mistake.
It was used well when Knuth said "goto considered harmful", but that is a clickbait title for an article which advocates structured programming. The title may get people to read the article, but the actual article is the interesting part, the "goto considered harmful" title itself is reductive and just gets copied as a meme into HN comments.
Beating normies over the head with physics 101 explanations--ones that don't even begin to address the complexity of the subject at hand--to silence perfectly reasonable lines of questioning, is harmful. Exceedingly harmful.
The comment is about how "that's harmful" is a terrible comment. It's just such an awful, terrible type of comment that I've let some ad hominem in there.
humans can dissipate 360W easily, though not necessarily comfortably.
that being said, the power usage is high. assuming uniform absorption, 4w/kg works out to roughly 200mw in the brain. here's a neuro paper that sets an optimistic limit at 40mw.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3807567/#B34
OTOH, we pump a lot more than that (relative to mass) into fly brains during imaging, although they're not expected to survive much longer than the imaging session. the laser in our lab is about 1w, after losses from the optics path and pulse picking, the power on the brain is usually around 20mw
At least that's what the back of the envelope calculations seem to suggest.
I've found a FCC limit of 1.6W/kg. That's a limit, not what is actually experienced.
Ok, so here is a list of mobile device figures: https://emfadvice.com/sar-ratings-radiation-levels-smartphon...
Highest listed is One plus 7t Pro at 1.394W/kg.
That's in the same order of magnitude as these as these NIH results. Perhaps if you need to use a mobile device for most of your waking hours try to keep it away from your head. Otherwise it's probably not a concern.
https://support.google.com/pixelphone/answer/10937646?hl=en
SAR is sort of a "maximum power density" measurement. It's not claiming to expose your entire head to that power density, just a small ~10 g measurement portion.
Yes. This is worrisome. The FCC limit is 1.6W/Kg.[1] Neural damage was observed in mice at 4W/Kg. Several high-end smartphones from Apple and Google get above 1W/Kg.
Those are worst-case numbers for smartphones, says the FCC. Average values are lower. Worst case for cumulative transmit energy would probably be sustained heavy upload traffic, such as streaming outgoing HD video. Transmit power is highest when near the range limit for a cell tower, since the handset increases power when more range is needed.
[1] https://www.fcc.gov/general/specific-absorption-rate-sar-cel...
Yeah, in addition to the inverse square law, devices also have a higher noise floor from adjacent devices broadcasting at higher power.
This is why banning microcells to "stop the dangers of 4G from harming our children" just increases the Tx power and SAR by orders of magnitude. But you can't argue with these people.
In any case this is burst power during very high bitrate use such as 4k video, loading webpages, or pulling app/os updates. No ones phone is going to push a watt during voice calls. More like a few mW.
https://support.google.com/pixelphone/answer/10937646?hl=en-...
Phone manufacturers are required to follow regulation in most countries on emissions with limits set in W/kg.
Same with "we gave rats massive amounts of artificial sweeteners and they have all kinds of health conditions" ok so maybe don't?