Testing for Invisible/Harmful EMF Pollution

This $28 device can show you if you’ve any possibly dangerous EMF radiation in your home or office.

Just because you can’t see, feel, taste or smell it doesn’t mean it isn’t there.  Radio pollution (to use a non-technical term), is a growing problem (or possibly not, depending on your personal opinion about the risk of modern day living while being constantly bathed by an ever increasing amount of radio waves, and at ever increasing frequencies).

Let’s start first of all by defining what we mean, when we refer non-technically to radio pollution.  Switching to its more scientific term – Electro Magnetic Force or EMF radiation – we are actually talking about both electrical waves and magnetic waves.  In a complicated process that one doesn’t need to understand, a radio signal transmits both magnetic and electrical waves, and the term EMF refers to both types of emission – or, at the risk of using an emotionally-scary but accurate word, both types of radiation.

Certainly, we can all agree there’s a lot more radio waves all around us now than there used to be.  Forty years ago, there were no mobile phones, no Wi-Fi, and few microwave ovens.  The average home had no radio transmitters inside it at all.  The only radiation we received was from the electrical wiring in the walls, possibly overhead wiring, and very very small amounts of EMF from our radios and televisions.  Radio and television stations were of course transmitting signals, but unless we lived right next to a transmitter, the strength of those signals were very low.

But now, do a mental inventory of your home.  Or do an actual one – log in to your router and see what is connected to it.  You might be very surprised to see how many items you have that are broadcasting radio signals via Wi-Fi.

I just checked my router, and it tells me I have 22 different Wi-Fi devices connected at present.  That number will grow when my daughter gets home later today, and would grow much further if I turned on all the tablets, Kindles, phones, Alexa units, televisions, Bluetooth devices and assorted other items.

I have so many different things connected I don’t even know what they all are.  Some of them I’ve named in the past, and some come with helpful names, but others are anyone’s guess.

Here are five of the devices on my network.  I can guess that “wemo” is one of the Wemo brand smart switches I can control with my Amazon Echo units, and the Roku_Ultra is a Roku box on my television.  The amazon-eccdc00c4 is either a Kindle or, well, I don’t know what – maybe an Echo unit.  But what is the device named “*”?  Or “ESP_52DACF”?   And while I’m assuming that “wemo” relates to a smart switch, anyone could rename anything with that description and then, if they discovered my network password, connect it to the network.

I remember, some years ago, being very surprised and anxious when I discovered an unknown device connected to my network.  Was someone spying on me?  Eventually, after an hour or so of turning things on and off, I found the guilty item – a legitimate item I’d simply forgotten about, but these days, I’ve given up entirely.

It is possible to get a hint as to what devices are by their MAC address field values.  A MAC address is a “Media Access Control” address or identifier.  In theory, every different network device, everywhere in the world, has a unique MAC identifier.  The first half of the MAC is a manufacturer identifier and the second half is a unique serial number for that particular device from that particular manufacturer.  Both parts of the MAC can sometimes be changed and faked, but unless there is someone very sneaky trying to infiltrate your network, that has probably not been done.

I checked the device shown as “*”  using a MAC lookup service, and was told that it is made by Arcadyan Corp.  I’ve no idea who they are or what of their devices I have (I found their website, but that left me none the wiser).

If I was to make a full list of everything that transmits radio frequencies in my house, I’d also have to include things like wireless microphones, some remote controls, walkie-talkies, garage remote controls, microwave ovens, and even a couple of “real” ham radio transmitters.  Plus the “smart meters” for my gas and power service, both of which have transmitters in them.

Then there is all the power wiring in the walls that is radiating EMF.  Most electrical appliances, when switched on, radiate EMF.  That includes battery powered items, such as my electric razor.  And other things one might overlook such as the heater pad on my bed.

Particularly now that 5G cell towers are starting to appear everywhere (although these days it is harder and harder to recognize them – the wireless companies, recognizing the growing controversy over their cell towers, are now disguising them as flagpoles, trees, and various other objects), we have to also consider all the external sources of radio signals too.  Overhead or buried power lines, telephone wires, cable connections, and all the wireless signals out there.  In some jurisdictions every street lamp has its own built in radio for communicating with the utility company, advising of its status and being told when to turn on and off.

Is All This EMF Safe or Dangerous?

So we all have some number of devices that actively are transmitting radio waves, plus other appliances and even just the wiring in our residences also adding more EMF energy all around us, and then the external sources of radio wave radiation too.

Is all of this safe?  That’s a key question, of course, and there is no settled agreement as to if they are safe or dangerous.  It reminds me a lot of the divergence of opinion about cigarettes in the 1950s and early 1960s – back when advertisements promoting cigarette smoking ran lines such as “More doctors recommend …….” or “Have a cigarette to help control your cough” and in other ways suggesting cigarette smoking was healthy and approved/endorsed by doctors (many of whom of course smoked themselves, too).

I’m reminded of that not just because of the way we are as eager to hope that the devices we’re every bit as addicted to now are safe as we were eager to believe cigarettes were safe all those years ago, but also because the billion dollar corporations that sell us these devices are keen to have them seen as safe; just like the tobacco companies were/are.

There’s no real major push by any group of people to establish that our beloved wireless devices are dangerous, and perhaps we’re all being a bit too eagerly myopic, and ignoring what is a growing issue.

One of the ways in which some people reason that electrical and magnetic fields must be safe is because the body itself uses electricity to signal and control some functions, and because magnetic fields naturally occur all around us – the earth’s magnetic field.  So both things are “natural” and therefore harmless, right?

Not necessarily.  Our world is full of natural but harmful things; natural never equates directly to harmless.  There are also very many things that are not-very-harmful in very low doses, but which in increasing doses become more and more harmful and toxic.

Some people look at the body’s use of electrical signals and rather than being reassured, view that as cause for alarm.  If the body uses electrical currents to control and regulate and signal some things, anything that might interfere with the normal processing of those signals is surely impactful?  This is known and sometimes even used for hopefully beneficial purposes.  But can we be sure it is and always will be only beneficial?

As for the earth’s magnetic field, it is a steady and only extremely slowly changing field, measuring about 25 – 65 microTeslas in strength depending on where on the planet you are.  We’d compare that to the difference between a steady wind blowing and a gusty wind.  One can balance against a steady wind, but a gusty wind can catch one off balance and blow one over.  Most of the artificial magnetic fields we come across are varying – alternating at some frequency – rather than steady such as you’d get from a magnet or the earth’s field.

In particular, when we see reports such as this it is clear that magnetic fields can have an impact on us, the same as electric fields.

Some people who prefer to believe that radio fields are safe point to the difference between “ionizing” and “non-ionizing” radiation.  Ionizing radiation is when the EMF is so strong it starts to knock electrons out of orbit and off atoms, and to break up molecules and directly damage living cells.  It is what most people mean when they generically talk about “radiation” or nuclear radiation in particular.  Non-ionizing radiation is any other radiation that doesn’t do what ionizing radiation does.

But it is an oversimplification to suggest that just because non-ionizing radiation doesn’t immediately and directly impact on cells, our DNA, our atoms and other molecules; that means it is safe.  For sure, ionizing radiation is truly dangerous.  But just because other radiation is non-ionizing does not mean it is therefore 100% safe.

You can get blinded by staring into a strong radar beam.  Microwaves heat tissues, which is good when you want to cook something, but bad if it is your brain or other tissue.  Remember it only takes a rise of a couple of degrees for us to have a fever, and a couple more degrees – at about 104°F (40°C) we are considered to be suffering from hyperthermia, a life-threatening condition that requires immediate treatment.  A milder version is the “heat ray” that the Defense Department has to create “active denial” situations, and which it has asked about deploying against US protestors.

And, as mentioned already, EMF can interfere with the body’s own electrical signals.

Just because we don’t exactly understand the impacts that external EMF might have on our bodies does not mean there are not any impacts, or that the impacts which have already been observed are uniformly and exclusively safe.  It just means we don’t yet know, and as a general rule, anything that interferes with the body’s normal operation is more likely to be bad than good.

Maybe a possible answer to the safe/dangerous question is that at low levels, and for short periods of time, EMF is safe.  At higher levels, and/or for longer periods of time, it becomes less safe, and at some point, it becomes dangerous.  In other words, and unsurprisingly, it is like other sorts of radiation too.  And just like you can get radiation detectors, for example, to tell you if you might possibly have a problem with radon in your home, you can get EMF detectors, too.

The question then becomes – how much is too much?  And how long is too long?

That’s of course the point where we might start to diverge in opinion.

EMF Measurements

There are a number of different ways to describe the amount of EMF in an area.  There are also two different types of measurement – one for the electrical field and the other for the magnetic field.  The electrical field is often measured in terms of volts per meter.

The magnetic field isn’t quite so self-explanatory.  It is measured in Teslas or gauss units.  One Tesla = 10,000 gauss, or 10 mG = 1 uT.

The Tesla is the more common and preferred (SI) unit, and usually for most of types of field strengths, the measurement is in microTesla units (1 Tesla = 1,000,000 microTeslas).

In case you wondered, 1 Tesla = 1 weber per square meter.  Yes, I know, that doesn’t really help, does it!  Just be aware that magnetic fields are usually measured in microTeslas, that the Earth’s magnetic field is about 25-65 uT, and household appliances can generate anywhere from as close to zero as possible up to about 200 uT.

In both the case of volts per meter and Teslas, the larger the number, the more impactful it is.

There are other measures, as well.  The FCC measures and limits the energy a cell phone can radiate, using a measure of how much energy is absorbed by the body, a Specific Absorption rate, expressed in terms of watts per kilogram of body mass (with a maximum of 1.6W/kg).

EMF Measuring Equipment

There are a number of different devices for measuring the strength of electrical fields.  They can cost several hundred dollars, and not necessarily with any guarantee of their accuracy.  I decided to get a low cost unit that might or might not work, but which definitely wouldn’t “break the bank” to acquire.  I chose this $28 unit on Amazon accordingly.

There are others only slightly more expensive that also read the temperature, but I didn’t see any value in that and it made the unit slightly more complicated.  I’ve plenty of thermometers already.

Although I don’t really believe the specifications, this unit claims to work with frequencies as low as 20 Hz and as high as 3.5 GHz.  That is truly hard to believe, and is much broader than some of the expensive units claim.  But it did respond to 2.4GHz signals (Wi-Fi and microwave oven) so obviously it has some very high frequency sensitivity, and also to 60 Hz mains power, so clearly it is in some way responsive over a wide frequency range.

However, as astonishingly high a frequency as 3.5 GHz is, the “high band” 5G frequencies are much higher – indeed Verizon has bands going up to a breathtakingly high 39 GHz.  So neither this device nor any of the others I’m aware of, even the several hundred dollar units, will report on 5G signal strengths.

The unit wisely avoids making claims about its accuracy.  I’d not consider it to be much more accurate than perhaps +/- 10% or even 20%, but as a “safe/dangerous” sort of indicator, that is probably sufficient.

The meter is very simple to use.  Turn it on, then wave it around and see what it reports.  If it detects a “too strong” electrical or magnetic field, it beeps loudly and a light flashes, and you can see on the display, all the time, the readings for the two values.

To be slightly more detailed, when using it, move slowly.  The device averages readings, and so if you move it quickly, you will be in and out of a strong field before the averaging responds to the brief peak.

The sensor is in the top – described as the “inductive zone”.

When measuring, make sure all nearby electrical and electronic appliances are operating, because if the power isn’t flowing, there won’t be any fields to measure.

What to Do With the Information

So you’ve gone around your home and discovered various “hot spots”.  In my case, my fears about my electric blanket on my bed were confirmed.  It radiated more electrical field energy than any other device – up to 650 V/m, and that is something I sleep directly on top of.

As you’ll see, field strength drops off very steeply with distance, but when you’re within a quarter inch of the field generating wires in an electric blanket, you’re getting a maximum dose.  The meter also answered a question I’d had – I had wondered if the thermostat/heat control worked such that at a low heat setting, it was sending out less radiation.  Alas, no.  So now I know to use it to heat the bed up before getting in, but not to leave it on at night.

I was also surprised to see how strong a field came from my clock radio on my nightstand.  Only a couple of feet from my head.  The clock radio is also connected to Wi-Fi which is, I believe, the reason for the strong emissions.  I’ve now moved it further away – I don’t need to be able to reach it these days because I use my Amazon Echo unit for alarms and playing music.

On a happier note, the microwave oven doesn’t seem to be leaking too severely (about 10 uT).

My cell phone, while not registering at all on standby, showed itself to be harmful, even six inches away, on both the electrical and magnetic field strengths.  That did not surprise me.

I have found some puzzling “hot spots” in the house that I’m going to need to identify.  But for now, I’ve reassured myself on some things and identified two things to optimize, so I’m generally pleased about it in all respects.

Ghost Hunting Too?

I noticed that some of the devices on Amazon are being sold as ghost hunting tools, in the belief that the presence of a ghost in some way upsets the normal balance of EMF forces.

To a rational person, that is a nonsense consideration, and indeed, to a ghost believer, it seems a curious marriage of magic and science to suggest that ghosts in some way create disturbances to the “real” world.  But I’ve not encountered a ghost while the device was in my hand, so I can’t comment any further on that point!


This is a device that you can probably live your entire life without ever really truly needing.

But if you’re interested in radio type issues, and if you’re concerned about EMF pollution, then for less than $30, it seems like an interesting gadget.  If not for you, maybe you know someone else who’d enjoy it as a stocking stuffer come Christmas time.

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