Comment by neuronexmachina | Hacker News Reader

Comment by neuronexmachina | Hacker News Reader

neuronexmachina

The actual study findings: https://ntp.niehs.nih.gov/results/areas/cellphones/index.htm...

From the fact sheet:

"Rats and mice were exposed to RFR in special chambers for up to two years, or most of their natural lives. NTP scientists looked for a range of cancers and noncancer health effects.

Exposure to RFR began in the womb for rats and at 5-6 weeks old for mice. The RFR exposure was intermittent, 10 minutes on and 10 minutes off, totaling about 9 hours each day. The RFR levels ranged from 1.5 to 6 watts per kilogram of body weight in rats, and 2.5 to 10 watts per kilogram in mice.

The chambers were shielded rooms with a transmitting antenna that radiated RFR fields, plus rotating stirrers that generated a uniform field.4,5 Pilot studies established field strengths that did not raise animal body temperatures excessively.6

The rats and mice were exposed to whole body RFR at frequencies of 900 and 1900 megahertz, respectively, from two technologies – Code Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM).

NTP and RFR experts from the National Institute of Standards and Technology (NIST) and the IT’IS Foundation designed and built the chambers specifically for these studies. "

Also:

"Were there any surprise findings? NTP found longer lifespans among the exposed male rats. This may be explained by an observed decrease in chronic kidney problems that are often the cause of death in older rats"

I particularly like "...strengths that did not raise animal body temperatures excessively." No sense microwaving the rats to death. For a 70kg person, that exposure (using the rat scale, 105 - 420 watts) for your entire life. Vs a cell phone which has an effective radiated power ERP of about 1 watt[1]. So somewhere between 1% and .25% of the power.

Cell phone signals fall off with the square of the distance so the bulk of the power of a cellphones RF energy that you are exposed to comes from the handset.

[1] "Meanwhile, the total power emitted from the cell phone itself ranges from 0.75 to 1 watt. According to the FCC (Federal Communications Commission), this is an acceptably safe amount of power for a cell phone since their cut-off or specific absorption rate is only 1.6 watts per kilogram (W/kg). As a result, the power radiated from a cell phone is considered as non-ionizing as opposed to ionizing." -- https://hypertextbook.com/facts/2006/EbruBek.shtml

What if you’re around 105-420 people with cellphones radiating 1 watt each?

Again, the energy falls off with the square of the distance, so unless those hundreds of people have very long arms and decide to press their phone against you...

Not trying to be a troll -- Tokyo subways come to mind.

1 watt corresponds to an in-use phone. Heavy data use. Even a call has much lower power. Unless the phone is actively doing something, the cell pings are very brief and use very little power.

You're discounting the fact that cell phones are more used for data than for talking and data is always being transmitted, especially with apps that run in the background.

Nah, the amount of power used for data is just also low when not being actively used. I'm sure some people update over 4G, but not many.

But how many people use their phones for data while holding them against their heads? (Not to mention in a shielded cubicle?)

And how many can even get service in a crowded subway?

most. offline people doing podcasts and games probably don't emmit much less.

Even then, how many people can be within touching distance? 10? 20 if they’re making a real effort? So let’s say 20 within a meter, and let’s say they’re all actively using their cell phones... it’s going to be significantly less than 20 watts, so still nowhere close. If a few hundred people beyond that are using their phones it will add an asymptotically diminishing amount of energy, so you’re never going to come close to the exposure these rodents experienced.

Also, when my phone is in my pocket I'm exposed to 50% of the radiation in one small spot vs. let's say 10% of the antenna's radiation spread across the whole body of the rat. Hopefully they tuned the power in their experiment to account for that.

No, when they talk about watts per kilogram I am pretty sure that they mean these were absorbed. Like they literally built 21 big microwaves, 7 for mice and 14 for rats, and then turned them on: it's no different than your microwave at home, the waves bounce around the walls until they find some water to call home. They're presumably not concerned with any microwaves that escaped the resonator.

They can't get close enough to you to matter. The way to think of this is to imagine a bubble around each person's phone. Just like a bubble gum bubble, the bigger it gets, the thinner it gets. So if its dark pink when it is emerging from your lips, it is transparent by the time it is 6" in diameter.

The energy of the cell phone transmitter is spread out further and further as you move way, and because the 'bubble' is both taller and wider, each meter (about 3') you step away from the phone, the signal is 1/distance^2 less powerful. So 2 meters away, 1/4 as powerful, three meters, 1/9th etc.

I like the Tokyo subway image, and others have gone to the trouble of computing people densities[1], if you take their number of 7 people per square meter as a good maximum, then 100 people divide into 7 person groups and you get a box that is about 4 meters on a side (12' x 12'). You're only getting 10% of the energy from the phones that are 3 meters away.

[1] http://www.elsi.jp/en/blog/2015/11/blog1126.html

Also, 2.5 W/kg in a shielded room is far, far more than 1.6 W/kg exposure. Cell phone radiation, when it even goes through your head, keeps on going right through to the other side[1]. In a shielded room, the radiation bounces off the walls until it's absorbed by the stuff in the room... ie the rats. The absorbed power in humans is microwatts. The rats were absorbing fractions of a watt.

[1]: as evidenced by the fact that cell phones actually work. When you cover them up with your hand, you don't suddenly drop the call.

No it isn't. W/kg is a measure of absorbed radiation.

No, it's just a unit. It's the output of your speakers to the amount of sugar I consume in a year if we want it to be.

We're talking about SAR obviously. Surely you could tell that?

Your original parent used the unit both for absorption and exposure; you replied claiming it wasn't a unit of exposure.

And a cell phone emits <1 W total, of which tens of millionths or less are absorbed. I was pointing out the difference between W/kg absorption and W/kg emission. These rats were absorbing tens of thousands of times more energy than you would experience holding a phone directly to your head.

I believe you added an extra "/kg" on emission.

No, he's pointing out that even (watts emitted)/(kgs of body region that is expected to absorb) is an over-estimate of watt/kg absorption.

Nope- It's a technical elision. An 80 kg man in an open field next to a 80 W transmitter is exposed to 1 W/kg, and absorbs microwatts/kg. Ionizing radiation is treated much more rigorously, and thickness and and frontal area are used to calculate the actual dosage, but for EM sources the wattage/kg is not unusual as a metric. It's useful for nearby transmitters, where exposure is focused on a single part of the body, vs simply being exposed to 80 watts of incident power.

> An 80 kg man in an open field next to a 80 W transmitter is exposed to 1 W/kg, and absorbs microwatts/kg.

That's not at all how it works.

https://en.wikipedia.org/wiki/Specific_absorption_rate#Mobil...

>"Were there any surprise findings? NTP found longer lifespans among the exposed male rats. This may be explained by an observed decrease in chronic kidney problems that are often the cause of death in older rats"

The increased lifespan could be at least partially responsible for the increased cancer rates. All populations that see an increase in lifespan see an increase in cancer rates. Cancer seems to be the default prize for living a long life.

Also, the caption on slide 20 for their BioEM2016 Meeting, Ghent, Belgium, June 8, 2016 presentation surprised me a litte. It states that the historical control incidence of malignant gliomas is in the range of 0-8%. This study saw a rate of 0% for its controls. That's not unreasonable but it is interesting. It's also odd that they did not see an indication of a dose response curve for GSM modulation, though admittedly the number of samples is low.

I don't doubt the statistical significance of the evidence presented, but data patterns suggest that it's at least a little possible that there's an issue with their protocol.

>The increased lifespan could be at least partially responsible for the increased cancer rates. All populations that see an increase in lifespan see an increase in cancer rates.

Of course, but wouldn't this be so obvious that the researchers would undoubtedly have accounted for that as a confounding variable? At least I hope so.

> Of course, but wouldn't this be so obvious that the researchers would undoubtedly have accounted for that as a confounding variable? At least I hope so.

Woudln't count on that these days, in general. If something is accounted for, it's usually stated in the paper.

That's what I thought, but I wasn't able to find where they addressed this issue. If you can point me to the control for lifespan, I'd appreciate it.

To make sure I understand the energy levels right: 6 watts per kilogram would be roughly like sleeping with a multi-kilowatt radio transmitter running in your bedroom?

Far more than that. It would be about half as bad as literally sleeping inside a microwave oven at full blast. The rats were kept in a shielded room so the microwaves bounce around until they are absorbed. It's no wonder they got cancer.

I do wonder why they got cancer. The industry always told us that non-ionizing radiation is harmless and it’s laughable that it should have ANY effect. So now there’s at least brain and heart tumors, and, strangely, improved kidney function.

Non-ionising radiation does not penetrate deep into the tissues but increases the risk of damage to the skin and eyes. Dependent on the energy and exposure time, non-ionising radiation can cause localised heating, or photochemical reactions can occur with possible permanent harm.

It's not totally harmless. Just orders of magnitude less than ionizing radiation.

I generally agree with you, but not with the "does not penetrate deep into the tissues" part. Non-ionizing radiation includes frequencies like 980nm (near infrared) which penetrates 3 centimeters deep at ~15W: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4552256/

Microwaves have wavelengths orders of magnitude longer than infrared light and can penetrate even deeper at the same wattage. It would IMO be VERY iffy to say that the possibility of photons emitted by a cellphone reaching the brain is zero.

I wonder if photobiomodulation is the cause of improved kidney function. PBM leads to nitric oxide release which in turn leads to lower blood pressure (beneficial for kidneys).

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