Eating a banana entails more radiation exposure if this is something you live in fear of.
World Health Organisation:
> A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use
> the current safety limits are set to include a 50-fold safety margin from observed effects of radiofrequency energy exposure
> There is no scientific evidence that proves that wireless phone usage can lead to cancer or a variety of other problems
National Cancer Institute:
> Studies thus far have not shown a consistent link between cell phone use and cancers
Forget for a moment the proported damage allegedly caused by cell phone radiation. Can you think of other kinds of real radiation that can indeed cause harm to living tissue besides ionizing radiation?
A photon emitted from a mobile phone's antenna has ~4 orders of magnitude less energy than a photon of visible light (E = hc/λ). If you're worried about your mobile phone, you should be terrified of light bulbs.
That's the energy carried by each individual photon. In terms of the number of photons, a typical lightbulb emits one two to orders of magnitude more; the number of photons illuminating a surface will reduce with the square of distance (assuming an isotropic radiator).
The illuminance in direct sunlight is two or three orders of magnitude greater than in an artificially lit room; sunlight also contains photons at UV wavelengths, which can carry up to two orders of magnitude more energy than visible photons.
Sunscreen is opaque at UV wavelengths but effectively transparent at visible wavelengths, partly for aesthetic reasons but mainly because the lower-energy visible photons cause negligible damage to skin. UV photons are sufficiently energetic to break apart bonds in DNA, but visible photons only carry enough energy to heat the skin.
Mobile phones are utterly feeble radiators, both in terms of photon energy and the quantity of photons. In terms of your exposure to electromagnetic radiation, they're a rounding error.
I am not a physicist, so I'm probably at least subtly wrong, but...
The photon has the same energy regardless of where it is measured, but the total intensity of the radiation (of all the photons reaching a unit of area normal to the source) decreases with the inverse square of the distance because the photons move generally (except insofar as they are acted upon by forces like the gravitational and electromagnetic) in straight lines at diverging angles.
> Can you think of other kinds of real radiation that can indeed cause harm to living tissue besides ionizing radiation?
Ionizing radiation isn't a "kind" like microwave or visible. "Ionizing" is a label you apply to all radiation for which any single particle has enough energy to kick out electrons from the atom it impacts. The only other "kind" of radiation is non-ionizing radiation.
1 watt at close range at 2.4ghz is lethal given enough time. It doesn’t matter that it ionizes or not. It is cooking tissue. The reason it isn’t killing all of us is that the body has time to repair itself between bursts. To say it is harmless is really wishful thinking for engineers.
The problem is that the distinction you're trying to make doesn't practically matter. As best we know now, the non-ionising radiation emitted by approved mobile phone transmitters is so minimally harmful that it is considered harmless. So it might denature a protein here and there, "cooking" an infinitesimally small amount of tissue, but any measurement of this damage, so far, completely lost in the noise. It is, for all practical purposes, as far as we best know now, harmless.
> 1 watt at close range at 2.4ghz is lethal given enough time.
Well, I'm curious as to how you determined this. It's plausible, so long as the target absorbs everything, radiates nothing, and is incapable of healing. Source?
Grossly, no, of course I wouldn't. However, the process of cooking things is essentially the process of using heat to denature and decompose components of tissue. So, it's not technically inaccurate to use the term if only a single protein is denatured by localised heating due to the non-ionising radiation. The point is that to use the term "cooked" in that way in this context is rather absurdly misleading.
The other part of this "cooked" term we're missing is that microwave energy (RF energy in the 300 MHz to 300 GHz band) only "cooks" things when there is enough energy at the excitation frequency of water molecules. That frequency is around 2.4 or 2.5 GHz. Most cell phones operate in the 700, 800, 900, 1700, 1800, 1900, and 2100 MHz bands.
See the Bloomberg link I added above recently
like most of you I ridiculed the notion that cell phone radiation is harmful. Have you ever had to pull your phone away from your ear when communicating a far away tower because of a very weird sensation. I have. It doesn’t prove anything of course but that I can sense it and that it is not comfortable makes me think Having it near my brain constantly isn’t going to lead to a good outcome.
That's pretty cool - have you been able to duplicate that weird feeling effect? Have others? Has it been double blind tested such that you can actually tell, with no other data, that your phone is transmitting with a higher power? Can you duplicate that same test with others?
That’s just not how it works at all though. It’s not causing any damage, it’s heating your tissue such a small amount that it doesn’t get anywhere near hot enough to ‘cook’ any of it.
You would need a lot more power, or an antenna pattern much more focused, and for it to be continuously emitting for a long time while very close to your skin to actually get hot enough to cause burns or denature proteins (which is about the only thing non-ionising radiation can do).
But phones don’t transmit all the time, but in bursts, and the antenna pattern spreads the radiation out.
Our company builds satellite antennas that focus 25-100W of RF power (in various bands from L band at 1-2GHz up to Ka at 29-31GHz) into about a 1 degree or so beam (big parabolic dish reflector), and at that point you need to take some precautions. I don’t have a single worry about phones.
There's a difference between a 60kW arc lamp and a 2W night light. The massive microwave transmitter on the tower (the arc lamp) is thousands of times more powerful than the phone in your pocket (the night light). Yes, it's the same light but being up close and staring at the arc lamp could very well blind you - but the night light, no matter how long one stares? No.
No, at this time, given the wide usage and absence of evidence of negative health effects despite wide deployment and study of the technology by a large number of otherwise unrelated entities, I have no concerns about about a negative impact to my health as a result of using permitted and certified mobile phone transceivers on and/or around my person.
However, per my arc lamp analogy above, I would certainly not like to find myself in an industrial microwave oven while it is on. Even if it's non-ionising, being cooked while alive is likely to be quite harmful to my health. But then again, if that microwave had the same power my mobile has - it'd be rather a rubbish microwave and I'd be perfectly fine.
Or lasers, standing in front of a radar installation, getting fried by a giant toaster. Take a tiny piece out of you and cook it in a microwave then put it back. Harmless? What if it came from your central nervous system?
Even though your proposition is outside of the scope of typical cell phone use, I would likely live just as long as I would have lived without it, given that its radiation is A) non-ionizing and B) not focused.
As an example, you could spend 14 hours a day in the sun to no ill effect, but only about two minutes with a magnifying glass focusing sun rays onto your forehead.
These figures are for radiation absorbed by an anatomical model, not the total radiation emissions. A phone with a higher SAR may simply have a less effective radiation pattern, directing less energy into free space and more energy into the user.
Yes. SAR testing uses a model of the head, with the phone held next to the ear. On a smartphone, you're essentially measuring the amount of energy coming out of the screen side of the device. When the device is being used handheld, this is effectively wasted energy, because most of it will be directed towards the sky rather than towards the horizon.
This is just a collection of published maximum SAR values. The FCC has an excellent article  about the reasons why these numbers are completely unsuitable to estimate radiation exposure a user receives from a particular phone model.
I'm not a scientist and it's difficult to parse these things sometimes but from the links you posted it looks like, despite the headlines, the takeaway is still "nah, it's fine..."?
They put rats and mice through 9 hours of 10m on, 10m off high power radio exposure over their entire body. For the rats, the exposure started from when they were in the womb.
After all of that, only the male rats were found to have a higher incidence of heart tumours. The male rats also lived longer due apparently to fewer kidney problems.
In female rats and the mice of both sexes, evidence of any cancers were "described as "equivocal", meaning there were measurable increases in molecules sometimes linked to cancer but no actual evidence."
I'm not trying to start anything and I think more research is always good, but based on those linked articles the substantive conclusion still seems to be that it's fine? I don't understand how the conclusion from those articles is that there is "clear evidence" that radiation from mobile phones causes cancer. Can someone explain this to me?
The point is, if there is no effect from ionizing radiation, then there would not have been an effect no matter what the dose of RF was. But there was a statistically relevant relationship between heart tumors and RF exposure.
So now that we know there is a relationship, the task is to dial down the RF radiation and see at what levels it’s not safe.
You seem very invested in this but the results from the study don't make much of a case I'm afraid. They found that rodents living their entire lives (from gestation) in what is effectively a low wattage (100 Watts from the article) microwave oven showed some higher instances of tumors in the heart, but only in some specific portions of the population (males) and not enough to impact their mortality rate which was for whatever reason higher in the control group.
Also from the FDA quoted in the article,
"We reviewed the recently finalized research conducted by our colleagues at the National Toxicology Program (NTP), part of the National Institute of Environmental Health Sciences within the National Institutes of Health, on radiofrequency energy exposure. After reviewing the study, we disagree, however, with the conclusions of their final report regarding 'clear evidence' of carcinogenic activity in rodents exposed to radiofrequency energy."
If you read above in the comments, everyone dismisses a link. The first step is to accept there is a link at high exposure and then dial it down to levels to figure out what constitutes a safe or unsafe level.
Right now everyone on HN is saying “RF is non-ionizing, it’s impossible to cause tumors!” when in fact it looks like RF does interact with biological systems in a non-ionizing method to produce tumors.
At what point does said conviction becomes "clear evidence" that vaccines cause autism? Since they have been insisting it for years out of some mix of greed and paranoia in spite of lack of evidence.
Doubled rates of very rare brain tumors? Do they not know statistics or are they being deliberately misleading? Because double a very small number is not significant. It is like worrying about getting shot by a dog with a handgun in his mouth at the beach. https://xkcd.com/1252/
E-M radiation is non-ionizing, but you can still get burned by it. One of the few major safety topics you'll learn in getting an HAM radio license is about RF burns. However, you have to use a fairly large amount of wattage (like more energy than a cell phone can even hold), and you have to stay located very close to the antenna. So it is _possible_ to receive a burn from a device emitting non-ionizing radiation, but you will not develop cancer from it. The wavelength is just too low to damage your DNA.
Meh. The largest single radiation source in most peoples' everyday environment are probably the ubiquitous H.sapiens ambulating all around them, emitting in excess of 100W per unit at around 12 micron wavelength.