Don’t Cook Yourself with RF Energy | Hacker News Reader

Don’t Cook Yourself with RF Energy

bigmessowires.com

72 pointszdw72 comments

I cooked myself with RF when I was a teenager.

Well, it was just my finger, but did it ever hurt!

I was setting up a new ham radio transmitter and antenna. I don't remember what I did wrong, but I got a nasty RF burn in my finger.

That's "in", not "on". Imagine a bad burn, but one where you can tell it's not just on the surface but goes deep into the tissue. And takes quite some time to heal.

I did have a lot of fun with ham radio, that one experience aside.

> And takes quite some time to heal.

Damn. How many years(?) did it take to heal? Did it heal fully or do you still have any residual effects?

Oh, it wasn't that long, just longer than a surface burn. And weird too: it didn't look nearly as bad on my skin as a typical blistering burn, but somehow I could feel that it went much deeper.

Luckily, I don't think my radio activities left any residual effects.

Wait, what did you just say?

From that day onward, they could receive FM/AM signal directly to their consciousness using their RF empowered finger-antenna, and they swore always to use their powers for the greater good. Nothing could possibly go wrong from there. Jokes aside, I wonder what effect intensive RF bursts could have on tissue compared to UV exposure or a burn?

Color blindness is a common injury among incautious radio engineers who stood in front of transmitters too many times.

Dish Network's satellite uplink station in Wyoming can "burn" away cloud cover when needed, and unfortunate birds have gotten cooked when they've flown over particularly intense beams.

I had no idea it was that dangerous. Thank you for informing. I didn't mean to make light of the danger.

I've worked on broadcast transmitter masts. I recall on FM masts RF burns were commonplace (things were a little different on TV towers). To minimize RF burns, the idea was to grab metal surfaces quickly so as to not get an RF burn (doing this avoided RF arcing onto one's skin).

One of the notable problems was when one's body could not come into direct contact with the metal mast. For example, one's on the mast/tower and working on something and one's legs are wrapped around the center pole of the antenna. In this situation one's legs are actually separated from the pole's metal surface by the thickness of the material in one's pants.

I recall ruining perfectly good pairs of jeans and overalls when the RF burned holes in them around the point of my knees (my knees being the closest point to the metal pole).

It was annoying for me to have to keep shifting about to minimize the RF arcing onto my knees (I say 'minimize' because I couldn't stop it completely).

After alighting down from the tower and inspecting my jeans it was not unusual to find about a half dozen blackened holes of a few mm (1/8") in diameter on the inside of both legs at knee height. Right, RF arcs through my pants did cause RF burns but for some reason they didn't hurt as much as I'd have expected. They were just a bit of a nuisance really.

BTW, when the arcing was happening I could smell whiffs of myself burning. At the time I considered this no big deal and I still don't. If one has to work on 'live' towers that are radiating VHF broadcast signals then one has to take these minor hazards/annoyances as part of the job.

___

Edit: I accidentally wore my good Seiko watch with an LCD on the tower one day and its display was ruined (the screen went completely black). Lesson: no electronic watches on 'live' towers. Wind-up mechanical ones are OK.

Also, do not attempt to use electronic multimeters on 'live' towers either (destroying a perfectly good Fluke won't get you any Brownie points). If you must use a multimeter on a 'live' tower, an AVO-8 is OK as long as the field strength isn't too high (figuring that out can be a problem which I won't address here, except to say that the field strength (power absorbed in the meter's components, i.e.: I^2R losses), should not exceed their limit).

The reason you can use an AVO-8 is that it uses a copper oxide rectifier which has an f(t) of around 20kHz. Note: there is no other multimeter that I know of with a copper oxide rectifier - all others use germanium diodes and the RF will blow them sky-high.

I cooked my brain with a phone. Many years ago I stepped off the plane in ATL with a European 3G phone, turned it on, wondering if it could connect. Held it to my head while it tried to connect. MISTAKE. Not finding base stations on its wavelength, it probably cranked up the power. I had a really weird and uncomfortable headache for two or three days after that. Do not try this at home!

The maximum power output of a mobile phone is ~200 mW (0.2 watt) and that happens only for short periods (miliseconds) at the time.

That is not enough energy to even penetrate the skin, much less the skull. The amount of energy the article talks about is 1000x that amount and for an extended amount of time.

A lot of travelers experience headache after flying. Blood pressure changes, blocked sinuses, CO2 accumulation, change in sleep cycles etc. can all contribute.

Source: degree in technical medicine

OK, good to know. It was a genuinely weird headache, but I misattribute it.

Wow, really interesting degree I haven’t heard much about. Could you please tell a bit on what are you working on/what could you work on with this title?

One thing I could never understand is this apparent contradiction: there is this trope that non-ionizing radiation doesn't cause cancer, which is repeated in this article, but it can also heat up and burn tissue, which can definitely cause cancer. So which is it? I understand that non-ionizing radiation doesn't directly create cancer, but can't it indirectly cause cancer?

Any single particle of ionizing radiation can cause damage; there's no threshold. For non-ionizing radiation to cause damage it needs to exceed a threshold.

Right, that's what I mean by "create" vs "cause".

Genuinely curious, can burning tissue really cause cancer? Like if I put my hand over a fire for too long and get a 3rd degree burn?

A full-thickness burn is going to cause a lot of problems; an increased risk of cancer down the road is likely to be the least of your problems.

That said, inflammation and tumors are surprisingly tightly linked: many tumors co-opt inflammatory pathways, or use them to establish favorable "micro-environments" that allow the cancer to proliferate.

Here's a review about the link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803035/

According to this it's rare

https://pubmed.ncbi.nlm.nih.gov/18176744

And according to the below there is evidence to suggest it can cause protein degradation and also DNA damage. That damage that tends to result simply in outright death rather than mutations which could cause cancer

https://pubmed.ncbi.nlm.nih.gov/19587691/

There is evidence that non-ionizing radiation can cause cancer.

https://www.nih.gov/news-events/news-releases/high-exposure-...

And weirdly:

> He also noted the unexpected finding of 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,” Wyde said.

Since when does heating up and burning tissue cause cancer? If that were true you'd expect burns to skin to have a higher risk of cancer.

It’s also not really relevant to the normal situation where you are exposed to low levels of non-ionizing radiation through radio waves at energy levels much lower than enough to generate heat, let along burning. If your phone is causing burning, you have an bigger, immediate problem beyond radiation exposure.

Burning (damaging) a cell can cause damage at the genetic level. If the cell divides you can get mutations. Any cellular damage can increase the risk of cancer via this series of events. Animal bodies have mechanisms to identify and eliminate aberrant cells, which is not 100% effective. This is biology 101.

> If that were true you'd expect burns to skin to have a higher risk of cancer.

There are a number of studies still trying to figure it out, since there is a high number of cases reported, despite evidence showing that it shouldn't increase. Some papers:

https://www.sciencedirect.com/science/article/abs/pii/S03054...

https://www.medicaljournals.se/acta/content/html/10.2340/000...

https://www.jstor.org/stable/20486296

https://burnstrauma.biomedcentral.com/articles/10.1186/s4103...

(from googling)

>> https://www.jstor.org/stable/20486296

Says no evidence of increase of cancer from burns. They also include chemical burns. Another article you linked specifically focuses on chronic immunosuppression.

Chronic inflammation, on the other hand, is well noted to influence cell mutation, so that is probably where the connection, if any, exists.

UVA/UVB radiation definitely causes cancer, and it's non-ionizing.

Wow, true. Interesting mechanisms of action:

https://www.sciencedirect.com/science/article/abs/pii/S09698...

"In the human skin, melanogenesis is initiated by exposure to UV radiation, causing the skin to darken. Melanin is an effective absorbent of light; the pigment is able to dissipate over 99.9% of absorbed UV radiation." https://en.wikipedia.org/wiki/Melanin

"Radiative relaxation quantum yields for synthetic eumelanin" https://pubmed.ncbi.nlm.nih.gov/15068035/

The key here is its "near ionizing" the mechanism is still based on photon energy for which RF does not have enough.

Near ionizing and up have non thermal effects, RF's much lower photon energy's only known action is thermal which requires orders of magnitude more power to create enough heat to damage DNA.

Any source that radiates low energy photons at sufficiently high flux density will inevitably cause tissue damage. For example, green light from a 5 mW laser is fairly safe, but green light will cause serious damage from a 20 W laser source.

The comparison between ionising and non-ionising radiation is really about Watts per photon. Low energy photons need significantly more flux density (i.e. brighter) to create the same amount of damage as high energy photons. So the trope is really about you don't need a very bright ionising radiation source to give you cancer.

Your comment is glossing over the fact that high energy photons cause damage through a different mechanism not available to lower energy photons. A higher dose of lower energy photons may cause damage still, but not in the same way

Ionizing means that a photon has enough energy to eject an electron from an atom, ionizing it. This can disrupt chemical bonds, hence the direct damage to proteins, DNA, etc.

Ionizing radiation can cause cancer directly by damaging the DNA of a cell creating mutations thus increasing the probability of cancer. Heat is just heat. In extreme cases, it can cause severe burns. Cancers caused by burns and wounds are rare but possible. I think you may have factored in UV radiation that we receive from the sun, but this is something else: higher energy UV rays are ionizing radiation.

“ also heat up and burn tissue, which can definitely cause cancer”

Where do you get that “fact” from? I have never seen any reputable source say that heat, even to the point of tissue damage, has any affect on cancer.

I’m too lazy to Google if this is true, but I recall studies linking drinking hot beverages (tea, coffee) to esophageal cancer, presumably from heat damage.

"Yerba Mate Straw Cancer" are the terms you need.

Seems to be quite a bit of noise about it from various places. No idea whether there is any truth to it though.

Continued inflammation over time has some connections to cancer, but it must happen over a long period of time in order to initiate a cell mutation.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6704802/

No increase of cancer from burn victims:

https://pubmed.ncbi.nlm.nih.gov/18176744/

The chain goes Heat -> Inflammation -> Cancer. It is well known that inflammation causes cancer. It is one of the biggest and often underlooked causes of cancer in obese individuals.

See https://www.google.com/search?q=obesity%20inflammation%20cau...

Funnily, for permanent hair removal, you actually insert a thin probe/antenna/needle into the tissue, then transmit three times each for 1 second at 13.7MHz at ~180W to destroy the surrounding tissue.

Cosmeticians sometimes also use this to destroy certain blemishes.

Wow. Do they do that in every follicle?

Yes, it takes a few seconds per follicle, and you’ve got to do it three or four times over half a year on each follicle. It’s obviously expensive and takes quite a while.

For most people, IPL or Laser is probably a better option.

Only up to blond hairs which then you have to switch over to electrolysis like me. I have red hair which is really a mix of different hair colors such as light brownish red, 'redder', and blond. Like right now I don't have any beard shadow but I do have many blond hairs left over.

They also use lasers and just intense light and electricity. All of these have very high power levels which cause cell heating and destruction.

The thing to keep in mind is the action is thermal and requires much more power than cell phones to have any effect.

I don't like being around antennas. Especially when hiking trails take me past one of those microwave horns. Maybe it's a phobia, but I always wonder if hiking trails were taken into account.

I sometimes feel the same way walking around in SF. There are just way too many buildings and fixtures that are actually antennas that are concealed to not look that way.

I measured 20mW/m2 around 2nd and Harrison.

Just curious, how did you measure that? Are you constantly scanning?

I had bought Extech RF meter for $600. It seems to be the most reliable and accurate.

> I measured 20mW/m2 around 2nd and Harrison.

For reference, on a sunny day the sun will dump 200+ W/m² on you in SF.

Q1: How much ambient RF spectrum intensity has there been during evolution vs. sunlight exposure?

Q2: How much has ambient RF spectrum intensity risen today vs. natural background levels?

A1: Virtually none.

A2: 10^18

this, it is not just about the intensity, it is that all organism have evolved to around sun exposure, not much around artificial light/Emf exposure...

The microwave horns are incredibly, incredibly tightly focused, though. (That's why they made 'em so big.) If you're not literally between the two ends of the link, you're not getting significant energy. And if the beam actually touched the hill, it'd diffract badly and spoil the signal.

Also I don't think any of those are still active, are they? Most of 'em that I've seen have the feed waveguides removed where they get near the ground. I always thought it'd be fun to make an adapter/coupler and stick a wifi card onto one of 'em because 2400Mc is within their passband, but I can't find a pair pointing at each other where both ends still exist.

Yeah they are. The inverse square law is very real when dealing with non-ionising radiation.

I used to work in radio spectrum governance, our inspectors who were clambering up towers on the regular made to sure to not stick their head or gonads in front of a focused microwave transmitter for more than 10 - 20 seconds (IIRC).

All of those inspectors have retired now, and none of them have brain or testicular cancer, likewise none of their children had birth defects.

So I think you'll be fine unless you're sticking your head in the dish :)

When I worked in comms the running joke was that all of us that did things with high powered RF would only have girls. No idea if there's truth behind it.

Interesting that Russian/Soviet limits on RF radiation exposure are an order of magnitude lower than US/EU ones.

Sounds like a way for them to pretend to be cautious and safe, relative to the west. How seriously do they take these "limits"?

All of western movie history would have us believe that there's the official limit on paper, and then there's the real limit in practice that Grigori, the underfed, overtired engineer-who-probably-shouldn't-be-smoking-around-all-that-stuff, actually has to work with.

The current situation makes that stereotype seem more and more plausible by the day.

Makes no sense in country where occupational safety does not exist anyway. Source: born there, seen that.

Don't extrapolate your own experience to everything else. I've seen quite opposite.

except the swiss (non EU i know). they also have lower limits than most.

> I don’t understand the reasoning behind this. Just because someone knows there’s an antenna, and has received RF safety training, how does that make their body less susceptible to injury from RF energy?

They a) know how to ascertain risk better and b) know what parts of their body are riskier to expose at close range to their antenna.

Safe exposure to RF is pretty well studied, and I've not seen a standard that wasn't set in line with prevailing science.

But, definitely agree that if you're not certain about the safety, get a certified radio engineer to install your antennae.

I worked in a lab testing Mobile network things. I was forever worried that some contractor would leave the radio antenna ports open without attenuators and termination, and unblocked. I considered buying a personal radio exposure warning device, but .. where do I wear it. In the end I guess I complained enough about cables on the floor being tripping hazards I got an assignment where I didn't have to go to the lab anymore.

An article from 80s? :)

>> Unlike x-rays or gamma rays, they can’t cause radiation sickness, genetic damage, or cancer. Rly?? Tell that to radar opertors/maintainers! Oh, and It was confirmed by scientists. Can't find the name of the woman who was a US president advisor on subject and (AFAIR) toxic materials dangers.

Well you definitely won't get radiation sickness, and you can't get genetic damage directly from the ionizing radiation (there isn't any). And people argue non-stop about whether you might rarely get cancer from RF exposure, since cooking tissue is damaging and could possibly cause cancer.

I think everyone in the know agrees, though, that the threat profile from ionizing radiation and non-ionizing radiation is vastly different.

If your device is hacked at the firmware level, it can be turned into a microwave weapon and used against you. (My hypothesis of the cause of Havana Syndrome: hacked cell transmitters beaming microwave at targets.)

Tech Ingredients (YouTube creator) made an instructional video about how microwaves work and how to defend against them: "https://www.youtube.com/watch?v=Lg_aUOSLuRo".

Uh... Millimeter wave communication is radio communication. Radio antenna.

Microwaves are not similar nor are cellular radios able to utilize microwave communications.

Microwave towers are specifically built at great height and are utilized for long distance communications.

One cannot turn a cellular device into a microwave, nor can one utilize microwaves to achieve cellular communications.

WiFi is microwave radiation. Just three orders of magnitude less powerful.

> Just three orders of magnitude less powerful.

For FCC that might be the case. CE/RED in Europe goes even as low (or as high, depending on which way you want to see it) as four orders of magnitude.

Microwave ovens run at 2.4 GHz. 4G cellular includes 2.3 and 2.5 GHz bands (among others). So in terms of absorption by tissue, cell towers absolutely have the right frequencies.

What they don’t have is the power level to have much effect beyond a few feet.

Microwave is a ridiculously broad term. By some definitions it is any signal from about 300MHz to 300GHz, but in the industry we don't really consider it microwave until you get to L-band (1-2GHz), and even then, compared to a lot of stuff we do that's extremely low frequency (I've worked mostly in X, Ka and E-bands - ~7-9, 18-19, 28-31 GHz up to 80-90GHz). But WiFi and cellular are definitely microwave, as are the big point-to-point links you're talking about.

Not that I'm agreeing with the parent comment - having worked in the microwave comms industry (and a little bit of radar) for about 10 years, the best explanation I've heard for 'Havana Syndrome' is closer to food poisioning than anything to do with RF. I think the US Government has basically walked back any claims that they were actual attacks recently too.

Besides things in pointed out in the other replies, I think the main error in this mental model is assuming there's a category difference between radio and microwave.

Microwave is just a term for a largish swath of the spectrum that encompasses millimeter wave, and lots of cell phone bands, and frequencies used in point-to-point microwave links, frequencies used by your microwave oven, wifi, etc.

That was an interesting video, thank you. Neat to see centimeter wave RF demonstrated so practically.

> If your device is hacked at the firmware level, it can be turned into a microwave weapon and used against you. (My hypothesis of the cause of Havana Syndrome: hacked cell transmitters beaming microwave at targets.)

No, no it can't. It is physically impossible for any part of cellular infrastructure, be it the phones or the base stations, to direct enough power at an arbitrary person to cause any effect. Phones simply don't have the power to harm a human and the inverse square law means that even high power base stations are safe from more than a few feet.

You may want to consider this: https://www.researchgate.net/publication/279863242_Oxidative...

TLDR; 93/100 available studies (2015) confirm that low-intensity RF causes oxidative-stress mediated tissue damage (incl. DNA damage) and is implicated in a wide range of cancer and non-cancer pathologies.

TLDR2; its not just about power levels.

There is a massive gap between "Long term RF exposure can cause cell behaviors that may have subtle effects" from the paper you linked and "Hacked cell infrastructure can be weaponized" as the parent poster was claiming.

I'm an IT nerd, not a molecular biologist, so I can't really comment on the paper in detail but a quick skim gives me the impression that whatever effect they're measuring is both subtle and generally not directly linkable to the kind of effects a person would actually notice.

Something that could be used to cause targeted injury would have to be multiple orders of magnitude more powerful. The most effective way to weaponize hacked cellular infrastructure would be accessing the data traveling over it, not a fantastical idea of turning it in to a RF blaster.

> If your device is hacked at the firmware level, it can be turned into a microwave weapon and used against you.

If anything your RF components go up in smoke. Modern chips are designed to only work at the desired maximum transmission power, sometimes even less to depend on idle times and such to save costs. But yeah, it's a nice entertaining conspiracy that keeps floating around nevertheless.

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