Radio ‘radiation’ Explained

Is your cell phone helping or harming you? Does anyone really know? Should we give it the benefit of the doubt?

This is the second part of a two article series about the dangers of cell phones and other devices that emit radio waves.  Here is a link to the first part – ‘Is Bluetooth and Wi-Fi Dangerous Too‘.

We hear a lot about the possible danger associated with using cell phones.  But what exactly is this danger?

First, we should be pedantic and correct one point.  The danger – whatever it may actually be – posed by cell phones and other types of radio transmitters is often referred to as a consequence of their ‘radiation’.  It is true that all such devices radiate (in the sense of emit or transmit) radio waves, but they don’t radiate radiation (in the sense of radioactive materials).

The official term ‘radiation’ is used to describe “ionizing” radiation – most commonly emitted in the form of alpha, beta, gamma and cosmic rays, neutrons, and X-rays.  When this type of radiation reaches our bodies, its ionizing property is such that it can ‘knock’ electrons off atoms and molecules, which changes the property of the thing so affected from stable to something ‘in search of’ its now ‘missing’ electron.  (Yes, this is an over-simplification, but the concept hopefully is conveyed through the simplification.)

Here’s a chart showing how, as the frequency increases, so too does its energy until it reaches the point where it can become ionizing radiation.

Anything with non-ionizing energy will generally transfer its energy into heat when it is absorbed by living tissue.

In most cases, and at very mild/moderate levels, heat is acceptable, whereas ionizing radiation can be thought of like spinning the roulette wheel in a casino.  Each unit of radiation (often measured in Sieverts or Rems) is akin to one spin of the roulette wheel, and in the event that the ball lands in, say, the 36 pocket, the ‘prize’ you win might be cancer.  Clearly a higher dose (ie more spins of the wheel) is worse than a lower dose, but even low doses might see you ‘win’.

And, just like with roulette, when you get a higher dose, you change from chance to certainty, and the risk of suffering effects of radiation poisoning becomes a certainty, with the only remaining issue being whether you survive the immediate effects or not.

Explaining Radiation and Its Effects

Radio waves of pretty much all frequencies are not considered to have sufficient energy as to become ionizing.  Think of ionizing as being a bit like knocking at a concrete block.  If you hit a concrete block with a straw, the concrete block will be unharmed.  If you hit it with a twig, it will probably also be unharmed.  A heavier piece of 2″x4″ timber might chip some bits off the edges of the concrete block, but that would be all.  But if you start attacking it with a hammer, you’re going to start chipping away at the block, and if you bring out a sledgehammer, you’re going to smash that concrete block to bits – maybe not in the first blow, but for sure, after a while.

It is the same with radiation.  Think of ‘normal’ radio waves as the straw, think of cell phone radio signals as something akin to a strong twig, and think of traditional ‘radiation’ such as alpha particles as a sledge-hammer.

So – from that perspective – radio waves are safer than ionizing types of radiation.

We mentioned above that ionizing radiation splits electrons away from their molecules or atoms. This type of molecular change can damage the DNA inside cells, and more generally, other ‘biological changes within cells’.  The damaged DNA and/or other biological changes may in turn encourage the occurrence of some type of cancer, and can create other effects, ranging from transient and minor (nausea, diarrhea, fatigue) to longer lasting (hair loss) and on to nasty things such as cataracts, internal bleeding, and eventually death.

What About Non-Ionizing Radiation?

Less powerful non-ionizing radio waves are absorbed by human tissue, and their energy is converted to heat.  A minor application of warmth for a short-term is not harmful, and is perhaps no more serious than soaking in a hot tub.  There are times when applying heat is actually therapeutic.

Unusually strong concentrations of energy may cause burns, and severe burns cause ionization damage and cell change.  If you were standing right next to a powerful antenna that was blasting thousands or even millions of watts of radio energy right at you, you would get burns, but most of the time, for most of us, the microwatts (ie millionths of a watt) of radio energy we absorb from the signals bouncing all around us, all the time, seem to have little apparent effect.

Think of a microwave oven.  This is how it cooks – it generates radio wave energy at a frequency that is readily absorbed into food (around 2.45 GHz), and the absorption of the energy causes the tissue to heat.  A short burst in the microwave warms something up, a longer time cooks it, and an extended time will crisp and potentially char it.

By an interesting coincidence, microwave ovens use frequencies which are very similar to common Wi-Fi and Bluetooth (both around 2.4 GHz) frequencies and close to the latest cell phone bands (they are a bit lower in frequency).

Microwave ovens usually generate about 1,000 watts of radio frequency energy, and a reasonably high percentage of that energy gets absorbed by whatever you place inside it.  Cell phones, Wi-Fi, and Blue-tooth devices rarely go over 1 watt, and chances are that less than half that is being absorbed by your body.

So what about the more moderate effects of the mild heating caused by phones, instead of the extreme rapid heating caused by microwave ovens?  How moderate and mild is it?

Radio Wave Type Heating is Very Efficient

We earlier spoke about heating and compared it to sitting in a hot tub, or spa, or sauna.  But we need to fine-tune that comparison to better explain the danger and effects of radio waves.

In your hot tub, you have a body temperature of around 98.6°F, and the water is probably around 104°F.  This is a very minor temperature differential, and the extra thermal energy has to make its way from the water, through the insulating skin barrier, before impacting on your inner body core temperature.  As you know, that is a long and slow process, and most people can enjoy 20 minutes or more in a hot tub before choosing to get out.

Now for a thought experiment – don’t do this directly.  First think of the experience when you put your hand into the hot tub.  The water feels warm, doesn’t it.  Now run the hot tap in the kitchen until the water is fully hot – chances are it will be around 115° – 120° F.  If you were to hold your hand under that, it would feel painfully hot.  You very quickly have to take your hand away.  So there’s a surprisingly big difference between say 105 and 115 degree water.  And if you’ve ever spilled (almost) boiling water on yourself (ie about 210° F), you know that is literally burning hot, and you’ll almost instantly scald your skin and create a visible burn.  Our body is very intolerant of temperatures outside its narrow range of comfort – and that is what we observe from our toughened outside layer of skin, which has been designed to withstand a moderate range of temperatures.  Imagine how more sensitive our internal organs are, which are designed in quite an opposite fashion – they are designed to work well at one temperature only.

Now think of cooking some food.  You could boil it in water for five minutes, maybe ten or twenty minutes, perhaps even longer, depending on the type of food.  Or you could stick it in the microwave, and have it cooked in maybe one-quarter the time, maybe less, again depending on the food and the quantity.

The microwaves cook even faster than boiling water, because they penetrate inside the item and heat ‘from the inside out’, rather than needing to pass in through the outer layer of ‘insulation’.

So if you can burn yourself almost instantly with boiling water, what do you think the effect of microwaves would be?  The microwaves instantly penetrate in through your skin and tissue too, and heat up tissue and organs inside you.  The only delay is the time it takes for the microwave energy to accumulate inside your body and cause a temperature rise to the point of having impactful effects.  Unlike your skin, your ‘insides’ generally don’t have nerves that are sensitive to heat, so you don’t necessarily realize that you are harmfully heating up your insides.

Our point here is that microwave (ie radio wave) energy and heat is silent but potentially deadly.  How much of a change in internal temperature is needed before it starts to seriously impact on our wellbeing?

Even Small Temperature Differences Can Quickly Kill Us

Consider the impact on your well-being and health that even a very mild amount of overall heating can cause.  Our bodies struggle to keep themselves in a very narrow temperature range, around 98.6°F/37°C.  Most of the calories we burn every day goes into a never-ending struggle by our bodies to keep our internal temperature close to this magic number.

If that temperature varies by much more than one degree F or half a degree C, we start to feel malaise and the onset of fever, and if it is an externally induced temperature change and exceeds only a very few degrees, we quickly move into the dangerous territory of hyperthermia (too hot) or hypothermia (too cold), and very shortly after that, the body ceases to be able to regulate its temperature, we fall unconscious, and death quickly follows.

So we know that keeping our temperature close to ‘normal’ is important.  Our skin tells us if the outside environment is too hot or cold, but our body has no easy way of telling us if one localized internal area is getting too hot or too cold, it can only tell us in vague terms if we’re completely too hot or cold.  In other words, just because we don’t sense anything impactful while using our phone doesn’t mean that nothing is happening.

How Much Heat is Too Much Heat?

Thermal imaging vividly shows how our brains absorb heat when we use our phones.  So there is no question but that measurable amounts of heat are being transferred from our phones and into our bodies and in particular, into our brains.

There are even studies which seem to suggest a propensity for tumors to form more on the side of our head where we usually hold our phones, but these studies have been criticized by some people as being insufficiently conclusive.

We now start to move into a speculative realm.  Given that some heat is being absorbed, how much heat is too much heat?  How much can the body handle?  No-one really knows, and this zone of ambiguity is what has allowed us all to ‘look the other way’ and hope that cell phones and other radio signals are all safe.

Cell Phone Dangers – Analogous to Cigarette Dangers 50 Years Ago?

Overall, there’s a very strong feeling of deja vu about the debate about cell phone dangers.  It is spookily similar to the debate over cigarette smoking/safety and the links between cigarette smoking and lung cancer.  It took many decades and much controversy to end up with sufficiently overwhelming a body of evidence to establish what some people immediately appreciated – a link between smoking and cancer.  Similarly now, it is taking many decades to come up with similarly incontrovertible proof, and we’re again in an interesting scenario where safety is assumed and danger has to be proven.

This is of course completely the opposite to how most new drugs need to be approved – they have to prove their safety.  One could ponder why it is that cell phone radio frequency emissions are assumed to be safe for extended contact at low levels, even when it is accepted that the same radio frequency emissions are definitely dangerous at high levels for short periods of exposure.

Most of us are as addicted to our phones as any of us ever were to cigarettes, and we truly don’t want to now discover that our wondrous new electronic companions are dangerous.  The cell phone industry too is keen to take full benefit of the doubt when it comes to inconclusive studies and lack of hard absolute proof, and for every study that purports to suggest a link between cell phone use and cancer, there are plenty of people eager to criticize some aspect of the study, often being people who benefit from the support in some form of the cell phone industry.

So, if there might be some dangers, is there anything you can do to minimize your risks?

The Importance of Distance

It takes a lot of energy to shift the core temperature of our entire 200 lb body up or down a couple of degrees, and no-one is suggesting that normal levels of radio frequency exposure would do that.  But – time for another analogy.  Think of a bare 40 W light bulb in the middle of a large room.  It provides even light all around the room, but nowhere is bright.  Now go and stand next to it.  Right next to it – no more than an inch away.  All of a sudden, that light has become so powerful that you can actually feel the heat radiating from it, can’t you, although that heat is only affecting a small part of your body.  But do your cheeks care that the rest of your body is normal if they are being roasted by the lamp immediately next to them?

We know that if we get very close to even a weak light, it becomes so bright and powerful as to dazzle us and causes us to feel the heat radiating from it.  It is the same with a radio transmitter.  Light and radio waves are essentially the same thing, just at different frequencies.

If you think about your lightbulb experiment, you know that if you almost touch the bulb, it is very hot.  If you hold your hand an inch away, you can feel the heat.  But by the time you’re a foot and more away, the perception of radiated heat drops way off.  Again, it is the same for radio waves.

In general terms, the strength of a radio signal declines in proportion to somewhere between a square and cube of the distance (depends on the antenna design).  So if you move from one inch away from the transmitting antenna to one foot away, that 12-fold increase in distance will see somewhere between 144 and 1728 times less radiation.  (To be ultra-accurate, the reduction won’t be quite this great, but it will still be substantial.)

That’s a huge difference, isn’t it.  Hold your phone away from your head (ie use a headset or speakerphone), and try not to carry it in a pocket close to your body.  These minor changes will massively reduce the amount of radio frequency energy your body absorbs.

Higher Frequencies Might be More Dangerous than Lower Frequencies

If you look up at the chart, above, you’ll see that the higher the frequency radio wave, the more likely it is to be capable of knocking electrons off molecules.  This shouldn’t be a surprise – there is a formula (E = hf) that was established by Einstein back in 1905 that describes this effect (Energy is directly related to the frequency of the radio wave, multiplied by Plank’s Constant).

For non-ionizing frequencies, there is a different effect – the lower the frequency, the larger the size of the radio wave that is created.  At 2.4 GHz the wavelength is about 5″, which means that all the energy is going into us.  At, say, FM frequencies such as 100 MHz the wavelength is almost 10 ft and so each wave is only partially absorbed by a person in its path.

What About the Electric and Magnetic Fields?

Radio waves are a combination of an electric and a magnetic field.  Our bodies in turn rely on electricity for things such as sending messages down nerves, and for brain activity.  A strong electric field can create related electric fields in other objects – that is how transformers work, for example.

Are the electric fields in the radio waves impacting on the electric fields in our bodies?  And if so, what does this mean?  The answer seems to be that no-one is very certain about this.

Even less is understood about magnetism.  You may have seen magnetic bracelets being sold as a cure for rheumatism and other ailments, and possibly for other disorders too, so possibly there is some impact on our body by external applications of magnetic fields.  Who only knows if a constant magnetic field is good or bad for us.

Even More Unknown Effects

We are moving into speculative realms here.  But that works both ways – should we assume that something we don’t know is dangerous is therefore safe?  Or should we assume that something we don’t know is safe is therefore dangerous?

There are some observed and some not observed issues that should be considered.

For example, we know that if you increase the heat in an environment, things within that warmer environment will typically grow faster – at least until the point where the heat becomes too hot.  So are we encouraging some things in our body to grow more quickly than other things?  Does this mean we’ll become comically lopsided?  Some studies again purport to show some lopsided growth perhaps as a result of where our cell phones are.

Or might it mean that we are selectively encouraging some things to grow faster than other things?  Some chemical reactions speed up with the application of heat, and some paradoxically slow down.  Are we altering the chemical make up and functioning of our tissue and cells by altering their ambient temperature?  Do some types of tissue absorb radio energy and heat up faster than other types of tissue?  What about cancer tumors – do they like to grow at a faster rate if they’re given a bit of extra warmth?  What about our brain – does it work better, or differently in some ways, if it is selectively warmed on the side of our head we’re holding our phone but not on the other side?

Another point of ambiguity is that the differentiation between ionizing and non-ionizing radiation is overly simplistic.  It isn’t like a light switch, either on or off.  The point at which radiation becomes ionizing is itself imprecise, and there are other effects that non-ionizing radiation can cause, beyond simple heating.

For example, various food items are sensitive to light and will age or ‘go off’ more quickly in light than in dark, even though visible light frequencies are not considered ionizing radiation.  Might there be other as-yet unguessed at outcomes?

If one wished to become fanciful, one could point to the apparent increase in the rates of all sorts of illnesses in society – Alzheimer’s, ADHD, autism, immune disorders of various types, and of course, cancers of all types.  The official answer is that we see more of these diseases because other diseases have been eliminated or can be cured, and because people are living longer, and because we are now diagnosing diseases more accurately.

Some analysts suggest that although autism rates have increased perhaps ten-fold in the last generation or two, this is just due to diagnosis and how we categorise the disease.  They might be right.  Or they might not.


So, we really don’t know.  The cell phone industry tells us that just because we can’t formally prove the presence of any dangers, we should assume there are none.

I’d love to think that is true.  You probably feel the same way.  But are you willing to bet your life on it?  The life of your children?  Because that’s what you’re doing at present, every time you turn your phone on.

2 thoughts on “Radio ‘radiation’ Explained”

  1. Pingback: Is Bluetooth and Wi-Fi Dangerous Too? - The Travel Insider

  2. thank you for sharing this informative article. i was considering buying a keyboard to use with my ipad and was surprised that almost all were bluetooth. i have not yet used bluetooth and have turned it off on my phone & ipad. i think i shall not purchase a bluetooth keyboard. also, i had recently considered plugging my child’s computer directly to the cable internet as opposed to wifi… this i was considering for connection issues but i am now much more motivated. honestly, i had stopped even worrying about wifi and only started the search today based in vague feelings of suspicion concerning bluetooth. i think i just got so used to not thinking about it. that is not a responsible attitude on my part, to be willingly ignorant. there are many subtle things in life that I have learned to routinely consider and this should be one. Again, thank you.

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