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Is RF radiation a concern?


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Actually, Quantum Physics shows a somewhat non intuitive property.  If a radiation source doesn't have energetic enough photons to cause a non thermal effect, ie, it is non ionizing, no matter how man

My apologies in that case!   Maybe I tend to overreact to the antenophobia nonsense because it irks me so much.

I love Mumbo Jumbo.    Thanks Jim!

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Im far from being a prude - but I found the original title just a bit crude - especially for a professional forum.

That's one of the reasons I changed the title. I also felt that the title invited crude but sometimes humorous comments about a subject which is not funny: health and safety while on the job.

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Some numbers for this discussion

 

(I looked up these values pretty quickly, so please correct me if I'm wrong)

http://www.newport.com/Laser-Damage-Threshold/144932/1033/content.aspx

The damage threshold for a green laser is approximately 50 kW/m^2 (The threshold gets lower as the frequency gets higher)

 

http://en.wikipedia.org/wiki/Solar_constant

The power constant of the sun on the Earth is on average approximately 1.36 kW/m^2

 

http://www.compeng.com.au/emc_conversion_tables_field_strength_calculator.aspx

The field strength conversion of a 650 kW TV station approximately 20 miles away: 132 dBuV/m or 42 mW/m^2

(132 dBuV/m is the highest field strength I could find for New York but there were multiple stations at that level)

 

http://www.compeng.com.au/emc_conversion_tables_rf_calculator2.aspx

Field strength of an idealized 250 mW transmitter at 1 foot: 220 mW/m^2

Field strength of an idealized 250 mW transmitter at 1 meter: 20 mW/m^2

 

Field strength of an idealized 100 mW transmitter at 1 foot: 88 mW/m^2

Field strength of an idealized 100 mW transmitter at 1 meter: 8 mW/m^2

 

Field strength of an idealized 50 mW transmitter at 1 foot: 44 mW/m^2

Field strength of an idealized 50 mW transmitter at 1 meter: 4 mW/m^2

 

Personally, I always just figured that there's so much electromagnetic radiation from TV stations and cell phone towers, WiFi, walkies, telemetry, etc, that I figured out transmitters were dwarfed anyway. I still think that the combination of transmissions we're exposed to constantly is more than our lower power transmitters, but it surprised me to see that the 100+ kW transmitters at a distance are comparable in field strength to our transmitters.

 

Still, we put up with much more damaging higher frequency radiation at much higher powers than these just by walking outside. I don't feel so badly about cell phones and the like.

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The problem with all the radiation levels listed above though, is, I think, that they are always there. That on its own is bad enough. So it always surprises me when people say, in response to a discussion like this, that there is so much radiation out there anyway so it doesn't matter. It's harmless by comparison. But I think that it adds up. Much like a beer is not a problem, but a beer every day could become a problem

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The problem with all the radiation levels listed above though, is, I think, that they are always there. That on its own is bad enough. So it always surprises me when people say, in response to a discussion like this, that there is so much radiation out there anyway so it doesn't matter. It's harmless by comparison. But I think that it adds up. Much like a beer is not a problem, but a beer every day could become a problem

I am pretty sure it doesn't stack like that, how much of that background radiation do our bodies actually absorb, and how much do we absorb from a 50mw transmitter on the small of our backs?

Sent from my Nexus 5 using Tapatalk

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I am pretty sure it doesn't stack like that, how much of that background radiation do our bodies actually absorb, and how much do we absorb from a 50mw transmitter on the small of our backs?

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I don't know, to be honest. I do know, as we all do, that frequencies interact with each other and that may or may not turn into something unhealthy. The beer example was not a good one though, I didn't mean so much that the effects of radiation are piling up over time, but rather that many devices in the vicinity can have effects.

The 50mw tx may be just a drop in the ocean or it's the drop that turns it all from good to bad.

AFAIK there is no conclusive evidence that a phone to your head for a long time is at all damaging, but there is no test that adds a 2.4ghz transmitter close by into the equation. The phone tests also usually don't say if wifi or bluetooth was enabled on the phone during the test.

It's difficult to say, but the possible negative effects shouldn't be dismissed to easily.

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As these are people who work directly in the field with hi powered microwave transmitters directly next to their head for hours on end, I doubt "scare mongering" is their motive.

They are marketing their own brand of protective clothing. Of course they are going to tell you of the evils of high power EMF. We know the risk and danger but any company selling a product will double the efforts to "sell" the product

But we work on the very far end of the spectrum, do we need protective clothing? No. How many times have we been told that we would develop brain cancer from mobile phones?

If I was that worried about radiation I would stop eating bananas.

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They are marketing their own brand of protective clothing.

 

Developed in response to their constant exposure to RF.  These are cam ops, not 'get rich quick' hustlers.

 

In a thread titled "Is RF radiation a concern?" I linked to one group of people who feel it could be.

 

There's no big conspiracy here, relax.

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The 50mw tx may be just a drop in the ocean or it's the drop that turns it all from good to bad.

 

My feeling was that it was a drop in the ocean until I saw the comparative levels. I still think it's rather a bucket in a kiddie pool though, particularly when compared to the blast we receive from the sun.

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Although it's not just a question of frequency, but power. Our transmitter emit 250mW at best, how much does your microwave do?

 

Power and frequency - microwave power emitted is on average 700 W

 

http://en.wikipedia.org/wiki/Microwave_oven#Direct_microwave_exposure - Non ionizing means that it does not have the same cancer risk of higher frequency radiation. Basically it warms the water in your body ever so slightly: imagine how long it takes for your food to heat in a 1000 W microwave, and then imagine how insignificant the heat from a 350 mW microwave oven would be.

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  • 6 years later...

There are biological effects from non ionizing radiation. It is not advised to have any device emitting 2.4 gHz  or 5 ghz, and most any other (especially digitally modulated with square and other digitally generated modulation schemes ) microwave frequency near your body.  Some people are more prone to it, some are less. Anyhow, the effects have been known for years now. French government banned Wi-Fi devices in nursery schools in 2015, and added a lot of extra requirements and warnings concerning use of such devices near children. 

 

There are scientists, among them Olle Johansson from Karolinska Institute, Magda Havas, and many others that have been studying the effects of the microwaves on human wellbeing.

I for one suffered from severe headache once from Teradek video village that spew rf thru a bad cable - and my boom op had the same symptoms, we talked about it afterwards. Tingling is also a known skin sensation to me, when the rf signal is stronger, it can be a burning sensation. You can believe me or not, i do not care - i was once able to detect wifi router presence when they first started to appear. 

 

Caution and good reason is advised. There are protective (shielding) fabrics, and since we as soundies know the RF propagation and how antennae work, can use the technology responsibly. The less RF, the better. Sometimes i get worried about camera operators having the 5 ghz Teradek router near their head for 12 hours a day. There are solutions that help a lot, thought - shieldheadwear.com for example.  

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As far as I know, there is no hazard unless the power is really high.

 

Let me elaborate: there are two possible effects of electromagnetic radiation: Thermal and non thermal. The non thermal effects (ionization) require a very high energy photon. The radiation capable of doing that is called ionizing radiation and the ionizing spectrum begins at the ultraviolet wavelengths.

 

Anything below that is strictly thermal. The photons simply don't have enough energy to do things like knocking a single electron from an atom.

 

I know there is a lot of bullshit (sorry about the word but it's true) on the matter. There are lots of fake/misunderstood studies. The best study I have seen, the Ramazzini Study, doesn't prove any harm beyond a couple of statistical artifacts. IF you take those statistical artifacts seriously, in one case it turns out mobile phone radiation would be beneficial, go figure.

 

Now: If mobile phone radiation (or the puny low power microwaves in use nowadays) were dangerous, think that mobile phones are working on the same frequencies former used for television broadcasts which used enormous powers. Cities have been blasted with such high power transmissions for decades. Effects? None.

 

Higher microwave frequencies. Have you ever visited a port? X Band radars transmit around 10 GHz. With power measured in kilowatts, and using pulses (some of the antenophobiac people claim that pulses make radio frequency energy more dangerous). Do people living around ports die en masse? No.

Do sailors suffer an unexpected high occurence of cancer? Not that I know, apart from maybe skin cancer in fishermen due to excessive exposure to sun light.

 

There are countless reasons to really doubt that radio frequency at the powers we use it (and even an order of magnitude more powerful) can cause any effect. And if it was dangerous, what about visible light with much more energetic photons?

 

If someone really proved any non thermal effect it would mean a Nobel award in Physics. Because it would tear apart all we know about the interaction between light and matter.

 

(I forgot, I mentioned radars and in another discussion someone wielded a study on cancer cases among radar operators without bothering to read it... True, there was a high incidence on radar operators due to improperly shielded valve electronics leaking X ray which of course is ionizing and very dangerous, but with no relationship to the microwaves transmitted by the antenna which anyway was far far away from the operator).

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Is RF radiation a concern? Of course it is. But only from the main source of radiation; the sun.

 

As noted by Endian, the sun is the most powerful source of radiation any of us will normally encounter; far more powerful than the combined radiation we endure from all other sources. Yet we fearlessly expose ourselves to its UV radiation every day. In fact, sunlight is essential for good health. Given that the sun exposes us to perhaps 1000 times as much energy as any other source, I'd say we can rule the others out.

 

 

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A couple of anecdotes… Long ago when I was appenticing under an engineer at a TV station he asked me to help him adjust the standing wave of a motorola two-way car radio. I think it was a MOTRAC 50 watt. He said grab the wire antenna while I key the mic. Holding the wire I said but wait.. Then he keyed the mic. Lesson learned, don't grab 50w RF antennas and don't trust this engineer. It took about a week for that burn streak to fade from my hand. It was like grabbing a metal kabob skewer right off the barbie.

 

Later, I worked for a Raytheon company were I was told that during WWII it was common for radio men to see if the radar was on by putting their hand in the microwave horn during servicing. If their hand warmed up it was on. Many of them contracted cancer.

 

There is also a company story saying this is how the first Radar Range Microwave Oven was conceived. An engineer noticed the candy bar in his pocket melted when he stood in front of the horn.

 

As we deal with RF in the milliwatt  range for sound gear there is no evidence of any hazard that I am aware of.

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2 hours ago, Paul F said:

 Given that the sun exposes us to perhaps 1000 times as much energy as any other source, I'd say we can rule the others out.


So basically we don’t need to worry about any other kind of radiation at all? 
 

I can’t believe this tedious discussion popped up again, but I won’t add much, said it all a few years ago. 
Except this: I hate every contribution to a discussion that says: we have so much of this one thing and it’s so overwhelming we don’t need to bother with anything else whatsoever. Like climate change deniers (or apprehensionists). When you say to them: if you stop flying it would save so much pollution, they‘ll just reply that there is no point, because everyone else is flying anyway, so it makes no difference. And even if everyone stopped flying, there’s still all these ships driving on heavy oil, that’s so much worse. And in the end no one does anything

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1 hour ago, PMC said:

A couple of anecdotes… Long ago when I was appenticing under an engineer at a TV station he asked me to help him adjust the standing wave of a motorola two-way car radio. I think it was a MOTRAC 50 watt. He said grab the wire antenna while I key the mic. Holding the wire I said but wait.. Then he keyed the mic. Lesson learned, don't grab 50w RF antennas and don't trust this engineer. It took about a week for that burn streak to fade from my hand. It was like grabbing a metal kabob skewer right off the barbie.

Yes but antennas can have quite a high voltage. I have a HF antenna in my balcony. It is a loop antenna with a capacitor rated for 5000 V. And yes, depending on the transmission power voltage across the antenna can reach that value.

 

So, no touch when using it. As I live alone it's not a problem.

 

1 hour ago, PMC said:

 

Later, I worked for a Raytheon company were I was told that during WWII it was common for radio men to see if the radar was on by putting their hand in the microwave horn during servicing. If their hand warmed up it was on. Many of them contracted cancer.

 

There is also a company story saying this is how the first Radar Range Microwave Oven was conceived. An engineer noticed the candy bar in his pocket melted when he stood in front of the horn.

 

And yet the most likely cause for their cancers, if it was related to radars even, was the X ray emitted by the vacuum tubes and not the microwaves.

 

1 hour ago, PMC said:

As we deal with RF in the milliwatt  range for sound gear there is no evidence of any hazard that I am aware of.

 

Exactly. Not even an order of magnitude higher powers should be a problem.

 

5 minutes ago, Constantin said:


So basically we don’t need to worry about any other kind of radiation at all? 

 

There are lots of kinds of radiation :)

 

So, I would say. Ionizing radiation (ultraviolet, X or gamma rays or nuclear radiation) is of course dangerous.

 

Visible light, unless you are using a laser, is not dangerous. Infrared? Well, it depends on power. If you don't sleep alone, your partner in bed will be radiating infrared. Of course the power is so low... ;)

 

According to Physics you shouldn't be afraid of the radio transmitters you use. Even walkie talkies with 5 W if you ever use them.

 

Now, if on April 1st Lectrosonics announced a gamma ray based wireless microphone, I would get scared!

 

 

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8 hours ago, Constantin said:


So basically we don’t need to worry about any other kind of radiation at all? ...


I hate every contribution to a discussion that says: we have so much of this one thing and it’s so overwhelming we don’t need to bother with anything else whatsoever.

It's my attempt to put things in perspective . Many people suffer fear of that which is not well understood. For example, there is quite some hysteria about 5G mobile. For those that don't have the inclination to read the many papers on the topic, an example, such as the intense sun radiation and how we deal with it on a daily basis can put in perspective what might be the concerns for things that are of much lower frequency and much lower power levels.

 

No, I'm not saying everything else is safe. But studies show no significant results that say we should be concerned unless we have jobs that put us in range of high powered radiation energy sources. But then you might say, how high is high energy. Well, there's the rub.

 

My first job was to develop high powered microwave transmitters for certain aircraft functions. In effect, I worked with high powered open-air microwave ovens. We did a study on it with negative results, although, I have to wonder what the cancer rate is of the crews of those aircraft.

 

With all of that said, I'd not be happy with a 5G transmiter on a pole near my house. Go figure.

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