A typical mobile phone base-station aerial systemZyra's front page //// Radio //// Cellphones //// Health //// Mobile Phones //// Site Index

The Dangers of Radiation from Mobile Phone Masts


There are fears that mobile phone masts present a threat to health. The emissions of energy from these towers is considered hazardous by some people. The fact is that mobile phone masts look pretty scary. They are big high-tech things that look like something ingeniously created in science fiction. Also, they're all over the place, like satellite dishes, and give the whole scene a "no longer last century" feel to it. Also, they often get conveniently situated on schools, churches, hospitals, etc, because like cats they like to have a good vantage point of the surrounding territory. With these great arrays of antennae you'd expect the amount of radiation to be given off would be something really astonishing, and that anyone quite close would be fried by the electromagnetic flux density. Pigeons, on landing on the deadly arrays, would drop dead Kentucky-fried*. Also, as commercial interests and authority spin have sometimes got a bad reputation because of safety assurance in the past which later turned out to be false, for example they said atomic energy was safe, it brings the whole scientific pronouncement business into disrepute! So, mobile phone masts, they must be dangerous, mustn't they? They Look dangerous, and I heard that someone who once went near a mobile phone mast one night a month later caught the flu, so, these things aren't safe, are they?

Well, it all depends on whether you want to look at things by guesswork and look-and-feel, or whether you look at the actual facts. I'm not going to tell you whether mobile phone masts are dangerous or not, but I am going to explain what the danger is in relative terms to other things. The thing that makes mobile phone masts a bit different to broadcast radio transmitters and pager transmitters and television transmitters, is the fundamental fact that the mobile phone masts have to transmit to mobile phones and receive from them! It is by its very nature a Two-Way communication. Also, all the phones the mast is in two-way communication with are within a short distance of it. There's no point in the tower communicating with phones hundreds of miles away when there are other towers inbetween.

Now, this is the key feature: The two-way nature of the system means that a mast will only talk to a phone if the phone can talk to the mast. Therefore the actual power output of the mast in its communication with a particular phone is similar to that of the phone it's in contact with. It's like being in the street shouting to someone standing on top of the tower, and them shouting back to you. If you were further away, there's no point in the person on top of the tower shouting ten times as loud if they can't hear your reply.

So, the actual power of the transmission is similar to that of an ordinary mobile phone. It's actually slightly more, but it's not vastly more. The mast is communicating on a two-way basis with a set of phones in its zone. There are typically a dozen channels and four time-slots, so in effect the actual total power is fifty times that of a phone. But because of the inverse-square law, the bottom line is this: If your head is seven times further away from a mobile phone mast than it is from a phone, you are being bombarded by more radiation from the phone than from the mast!

A typical mobile phone base-station aerial systemSo, if you are right underneath a mobile phone mast in a school playground, you are probably 40ft from the mast aerial, but if you use a mobile phone anywhere at all, you've got the phone right near your head, which is very considerably nearer than 7 times. So, if phone masts are dangerous, then using a mobile phone is reckless and lethal. (I've recently seen a tabloid sensationalist article in which someone said mobile phone masts should be banned within a mile of schools. This is badly informed, and such a move would actually increase radiation exposure!**)

However, no-one thinks of the phone as dangerous because it's just a small neat gadget that you can carry around and besides everyone's got them and they don't suffer from it. Meanwhile the mast looms dark in the distance as if some sinister sci-fi threat is upon us. The fact is that because of the two-way communication, if there's any danger it's the phone that's the more dangerous!

The other thing is that there are much more powerful transmitter masts around all over the place, but you can't see them. Therefore they don't appear so threatening.

Also, the type of radiation involved is important. It's not radioactive or ionising radiation, it's radio waves. It's like light in lots of ways. If you could see the radio waves coming off mobile phones and off the mobile phone masts, the phone would glow like a bedside light, and the mast would be a combined set of lamps which in total would amount to approximately as bright as a 100 watt lightbulb. But as it's right up on top of a building it would not be as blinding as if you stared right into the bedside light of the phone.

The conclusion: Mobile phone masts; if they're dangerous, then using a mobile phone is much more dangerous. You receive a small dose of radio waves from a phone, but an even smaller amount from a mast, even if you are quite close to it.


A few extra notes:

It is true that even if a mobile phone mast is emitting a power similar to that produced by a mobile phone, the cumulative dose over a period is higher than this initially suggests, because the mast is powered up all the time, whereas a mobile phone is in use for less than 24 hours a day. Yes, I know some people seem to be on their mobile phone all the time, but at least they don't make calls in their sleep.

If anyone says "cumulative dose", don't panic! Only a very few things are dangerous as a cumulative dose, for example mercury vapour, x-rays, etc. In contrast, you shouldn't expect to suffer deafness even though your cumulative dose of sound is higher long-term from birds whistling in the trees than it is from going to a rock concert every few months.

It's important to understand, when estimating how dangerous (or otherwise) radio masts are, that there are many different types of radio masts. Often the ones that give off the highest amounts of electromagnetic radiation are the least obtrusive. An almost covert aerial can be the main source of radio in a region where it goes unnoticed, even though campaigners are petitioning to ban a nearby phone mast tower.

Another good point that has been made by a contributor goes something like this: Why should we the people who don't have a mobile phone have to put up with the presence of towers that are for the purpose of other people's mobile phone communication? This idea, which is a bit like the issue of passive smoking, is relevant, but with this kind of thing it's best to "live and let live" wherever possible. I, as a diabetic and a coeliac, generally succeed in tolerating the annoying chimes of ice cream vans driven by purveyors of glucose-filled wheat-laden cones. Good luck to them in pursuing their business interests!

I also agree with a point raised by another contributor who suggested that a radio intensity survey contour map be created for a proposed development when a new radio emitter is to be put up. However such data shouldn't be considered in isolation. A wide variety of sources contribute to the background radiation, and this can easily be higher than that from a particular mast. We survive quite well despite wide-band radiation from the sun, highly energetic cosmic gamma particles from distant exploding stars, stuff left over from early nuclear tests, and the combined output of many high powered terrestrial radio transmitter towers.

* Kentucky-Fried Pigeons? Now the thing is, please Read the stuff carefully and see what is actually being said! Don't jump to conclusions, and don't take other people's word for it if they have made mistakes interpreting it. To be clear about this: It is a hypothetical scenario which is obviously productio-ad-absurdum, as you Do Not see dead pigeons because of mobile phone masts! Mind you, You never see Baby Pigeons, either do you?

** If you ban mobile phone masts near schools, this will increase radiation exposure. This is because the mobile phone itself adjusts its power level to an appropriate amount to communicate with the nearest mobile phone tower. If that tower is near, the mobile phone will run at a lower power. If the tower is more distant, the phone will "shout louder" to communicate with the tower. As the mobile phone itself is the higher source of radio emissions as it's near your head, moving the towers further away will increase the total amount of radiation which children are subjected to.