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“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?
by jacobn 4y ago
“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?
- chaosmachine 4y agoIs it? The Pixel 6 has a SAR of 1.4 W/Kg.
- cpncrunch 4y agoMost of that will be blocked by the skull.
- asdff 4y agoBig assumption that all humans have an intact skull
- otherotherchris 4y agoI feel that this is an edge case that only applies to unencrypted radio transmission in Ukraine. Please get back on topic.
- scotty79 4y agoHeat from 1.4W/kg for an hour might be significantly easier to dissipate than 4W/kg for 5 continous hours. At least that's what the back of the envelope calculations seem to suggest.
- sras-me 4y agoWhy do you assume heat to be the bad guy here?
- XorNot 4y agoBecause chemically 835mhz is non ionizing radiation. It doesn't matter how much you pour in, electron and molecular orbitals will ignore it.
- sras-me 4y agoBy that logic photoelectricity should be impossible with non-ionising radiation, right?
- doikor 4y agoWe know that 835MHz is non-ionizing radiation so there isn’t really anything else than heat that it could do to cells.
- ruined 4y agoare you sure? cited studies by TFA seem to indicate other effects, such as immediate changes in dopamine, GABA, and NMDA https://pubmed.ncbi.nlm.nih.gov/15571980/ https://pubmed.ncbi.nlm.nih.gov/15571980/
- topspin 4y agoPlease provide a reference for that 1.4W/kg figure. 4.5kg human head would need 6.3W to see 1.4W/kg. A cell phone such as a pixel 6 is 2W and that power isn't all pointed directly at the head. 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-smartphones/ 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.
- zootboy 4y agoReference: https://support.google.com/pixelphone/answer/10937646?hl=en 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.
- Animats 4y agoThat's in the same order of magnitude as these as these NIH results. 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-cellular-telephones https://www.fcc.gov/general/specific-absorption-rate-sar-cel...
- ruined 4y agocheck out the works cited of TFA, many of them involve 1.4-1.6W/kg SAR
- otherotherchris 4y ago
- mhh__ 4y agoCitation? How does the phone have an exposure rated per kg?
- seszett 4y ago> In the countries where the Specific Absorption Rate (SAR) limit is 1.6 W/kg averaged over one gram of tissue, the highest SAR values for this device type are 1.19 W/kg for Pixel 6 (G9S9B), 1.20 W/kg for Pixel 6 (GB7N6/GR1YH) and 1.11 W/kg for Pixel 6 Pro when used against head with no separation and 1.20 W/kg for Pixel 6 (G9S9B) or 1.20 W/kg for Pixel 6 (GB7N6/GR1YH) and 1.19 W/kg for Pixel 6 Pro when against body with 1.0 cm (0.4 in) separation. In the countries where the Specific Absorption Rate (SAR) limit is 2.0 W/kg averaged over ten grams of tissue, the highest SAR values for this device type are 1.00 W/kg for Pixel 6 (GB7N6/GR1YH) and 0.99 W/kg for Pixel 6 Pro when used against head with no separation and 1.38 W/kg for Pixel 6 and 1.40 W/kg for Pixel 6 Pro when against body with 5 mm (0.2 in) separation. https://support.google.com/pixelphone/answer/10937646?hl=en-GB 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.
- hales 4y agoThis experiment seems hot. Scaled up to an approximate human mass: 4 W/kg * 70kg = 280W. Apparently an idling human burns very approximately about 80W ("basal metabolic rate").
- wtallis 4y agoI'm not sure they were testing with exposing the entire mouse to that intensity; they were specifically concerned with measuring the effects of that intensity of exposure on the cerebral cortex.
- scotty79 4y agoIt's still probably thermally cooking its brain.
- jrapdx3 4y agoAccording to the article thermal effects of the RF exposure were minimal to nil. There was evidence of damage to brain cells that was attributed to RF exposure. However mechanisms leading to damage within the cortical neurons aren't clear. The RF exposure induced intracellular responses to stress and damage to myelin sheaths, the latter was thought responsible for observed hyperactivity.
- namibj 4y agoOnly those parts of the body that happen to have good blood circulation or that are expected to need to sink a lot of heat have the structures necessary to couple significant EMF absorption into the main bloodstream "liquid cooling loop". 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.
- bell-cot 4y agoAn older iPhone battery (not powering a huge screen, CPU, etc.) might have a 4Wh capacity, and be (claimed) good for 10 hours talking. Only a fraction of that goes to the radio signal, most of that signal not absorbed by the user's body, said body weighing many kg, etc. SO - actual exposure in human cellphone users is likely 2 or 3 orders of magnitude lower than in this experiment. 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.)
- upsidesinclude 4y agoThat was the total SAR for the entire cross section, not the specified tissue in question (2 orders of magnitude). Additionally, nearly everyone is in close proximity to multiple sources of EMF not their own phone solely. 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.
- bell-cot 4y agoAs others have noted, scaling 4W/kg up to humans gives a heat input ~4 times what human office worker's base metabolic rate provides. It would be profoundly obvious if all those more-distant sources were actually pumping that much energy into office workers. 10% of 4W/kg would be close to the BMR heat input in many workers such as older women. At even 2% of 4W/kg, it would probably be cheaper to install Faraday cages around office buildings (bridged by low-power-inside repeaters) than it would be to pay the electric bills for increased AC use (needed to get office workers comfortable enough to be productive). 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#National_Radio_Quiet_Zone https://en.wikipedia.org/wiki/Green_Bank%2C_West_Virginia#Na... ).
- raverbashing 4y agoSounds like another bad-faith experiment designed to create controversy Same with "we gave rats massive amounts of artificial sweeteners and they have all kinds of health conditions" ok so maybe don't?
- szundi 4y agoAlternative title suggestion: Mice put in microwave showed symptoms of agitated behavior
- adrianN 4y agoThat seems like a reasonable thing to do in a study where you want to check whether there is any effect at all. You'd now do a followup study to see at which dosage you stop measuring the effect.
- throwanem 4y agoIt's twice the highest legal limit anywhere in the world.