Because of the announcements that have been made over the last few years, research on the hazards of cell phone radiation in the US has dropped to almost zero. Interestingly, though, research in other countries is still going on, and it is showing that the problem is, indeed, worthy of a closer look, particularly in light of the recent increases in brain tumor rates in the US. They have increased by over 25 percent since 1975; by 2001, in fact, 185,000 Americans had some form of brain cancer, and it has been estimated that this will increase to 500,000 new cases per year by 2010, and to one-million by 2015.
Why are cell phones dangerous? To answer this it is best to begin by looking at how they work. When you receive a call, an electomagnetic signal is beamed from the nearest cell phone tower.(These towers now dot the landscape, so you're never very far from one.) This signal is picked up by the antenna on your phone. (As an aside I should mention that this signal is 10,00 times stronger at the antenna of your phone than it is if you were standing 35 feet from the base of the tower with the transmitter 35 feet up.) And of particular importance, the antenna on your phone is only a few inches from your brain so that 70 to 80 percent of the energy of the signal is absorbed by your skull, with much of it penetrating through to your brain. Furthermore, if you happen to be in a car, the intensity of this radiation is much greater.
One of the main arguments against the dangers of cell phone radiation is that the signal is low energy radio frequency (RF) radiation, and this energy is too low to have any effect. Although the signal is in the radio frequency range, it's actually microwave radiation -- the same type that is used in your microwave oven, and it also very close to the frequency of radar radiation.
The central argument along this line is that although these waves are used for heating (as in a microwave over) the energy of the phone waves is too low to heat tissue. And that is true; they are at least a thousand times weaker than microwaves oven radiation. But it's important to remember that low energy microwaves are chosen for cooking because they easily penetrate food, not because they are highly energetic. Another argument on their safety is that they are not ionizing, so they cannot knock electrons from atoms and cause such things as free radicals (which can do a lot of damage). Again, that is true, but as any physicist will tell you, you don't need ioizing radiation to do a lot of damage. Non-ionizing radiation is quite capable on its own.
This section may sound a little technical in places but it will help you understand the electromagnetic waves a little better so I hope you'll stick with me. Electromagnetic waves (or radiation) range from very short-wave gamma and x-rays through to very long wave radio waves. In between we find ultraviolet, visible light, infrared and microwaves. Radio waves have a wavelength from a few meters up to hundreds of kilometers (or miles, if you prefer). Microwaves have a wavelength of the order of one to ten centimeters; x-rays, on the other hand have a wavelength of approximately one nanometer, which is a billionth of a meter. So it's obvious that the range is exceedingly large. In the same way, the frequencies (vibrations per second) of the waves also vary by a large amount. The short wavelength waves have high frequencies and the long wavelength ones such as radio waves have low frequencies. As it turns out, frequencies are also related to energy: the higher the frequency, the higher the energy. This means that X-rays have lots of energy while radio waves are low energy.
Microwaves, which are the ones we are interested in, have relatively low energies. They are, in fact, right next to infrared in the electromagnetic spectrum (the spectrum of all radiations) and as you likely know, infrared radiation is heat. The infrared radiation from the sun supplies us with the heat we need to exist.
When we talk about microwaves we usually use their frequency rather than their wavelength. It is given in terms of Hertz (Hz), which is the number of vibration per second, or more exactly, in megaHertz (MHz or a million Hz). The range of frequencies that cell phones use extends from about 850 MHz to 1900 MHz. And let me emphasize that there's no doubt that high intensities of microwaves are dangerous -- extremely dangerous (they will fry you). So the question we need to ask is: are the microwaves in a cell phone powerful (energetic) enough to cause damage? They are, indeed, low power devices. The early analog devices used about 1.3 watts and the more recent digital phones use about .2 to .6 watts. This is obviously a lot less than the 60 watt bulbs you have around your house, and miles less than the 600 to 1100 watts that your microwaves oven uses. But is it enough less?
Another unit that is important in relation to cell phones is the SAR, which is short for Specific Absorption Rate. It is defined as the relative amount of microwave energy absorbed by the head of the user of the cell phone. The FCC limits the SAR elvel in cell phones to 1.6 watts/Kgm, which is relatively low (but there is some evidence that it is too high).
This is obviouly a central question? So let's get to it. As it turns out, different types of radiations are dangerous in different ways. Everyone know that x-rays are dangerous. They are highly energetic, highly penetrating, and can easily pass through your body. And while they're passing through they also pass through a lot of the cells and DNA in your body which is, of course, bad news as they can easily break up DNA and even if they don't, they can cause "mutations" or defects that change the "code of life" contained within the DNA.
So x-rays aren't something we want around us. What about the other types of radiations? In the center of the electromagnetic spectrun we have ordinary light (it may be a surprise to you that ordinary light and x-rays are basically the same thing, but with different wavelengths), infrared and ultraviolet. For the most part they aren't terribly dangerous, but high intensities of infrared can burn you and ultraviolet... well, it can be dangerous, and you can get a pretty good dose when you get a suntan (so be careful). But we're mainly interested in microwaves so let's get back to them.
As I mentioned, microwaves are used to heat things (as in a mocrowave oven) so let's look at this first. Our first question, then, is: Are the microwaves from a cell phone powerful enough to seriously heat the region near the ear where the phone is placed? It's easy to show that it isn't, and it would be great if that was the end of the story. But it isn't. It is possible that damage can occur in other ways, and because of this we have to look at the effect of microwaves on three things in our body:
Our DNA
The cellular function of our cells
The neurons and so on in our brain
Let's look at our DNA first.
DNA is a long complex molecule that is composed of two strands, one wound around the other like a spiral staircase. The backbone of the DNA chain is made of phosphate and sugar, and projecting out from this backbone are one or other of the base units adenine, thymine, guanine and cytosine, which we usually refer to by the letters A, T, G, and C. The two stands of DNA are held together because A bonds only with T, and C bonds only with G. This means that when they are separated and you look down one strand you see a sequence such as ATTGGCTAA and so on. This is the "code of life," and it contains all the information that is need to sustain and duplicate the cell that the DNA is in.
Cells divide only when they receive a signal from a growth factor that circulates in the blood stream, or from cells they came in contact with. When a cell receives a message to divide it goes through what is called "mitosis." Many reactions are involved in this process and everything has to take place correctly for the cell to divide properly. All in all, it's a complicated process, and if the DNA becomes damaged or mutated, it will not occur properly. Several types of mutations are possible: breaks, electrons or protons getting in the way and so on. One of the major problems is what are called free radicals; they are oxygen atoms that are lacking an electron, and are looking around to steal one. If they get near a DNA molecule while its strands are separated and steals one it can cause problems; even worse, it might decide to attach itself to one strand of the molecule, and if it did, the code of life would be changed at that point, and it would stay changed for all future copies.
All of the above are caused by radiation, but not necesarily by microwaves. The probability that microwaves could cause strand breakage is small; it usually takes more energetic radiation. Furthermore, microwaves can't create free radicals; ionizing radiation is needed for that. But that isn't the end of the story. For now, though, let's look at cellular function
The DNA within the cell also controls the various functions of the cell, and one of the most important of these functions is how the cell reacts to objects and other cells that come in contact with its surface. To deal with them it has "receptors" on its surface; they determine whether or not to let something pass through. Nutrients are, of course, needed to sustain the cell and keep it healthy and they must pass through. But there are millions of dangerous things such as bacteria, toxin and viruses that try to get in continuously. The receptors have to make sure they don't get in. And as long as they are in good shape they do a good job.
These receptors also play another important role: they can shut down cell division. Normally, cell division will continue until something tells it to stop. One of the things that stops it is when the dividing cell comes in contact with another cell (maybe of a different type); the receptors on the cell sense that the division should stop and they send a signal to the cell. Stop and start signals are contolled by certain genes (a stretch of about 100,00, DNA unit that are associated with one another). As long as the receptors and this gene are working well, everything goes along smoothly, but if either becomes damaged... I don't think I need to draw you a diagram of what might happen.
So, what has all this have to do with microwaves? Plenty. Studies have shown that micowaves (even though they are of relatively low energy) can trigger the receptors on cells, causing a series of biochemical reactions. And this can cause the cell membrane to become less permeable. We're still not sure how great the effect is, but it is possible that it might restrict the nutrients that are coming into the cell (and the the wastes that are suppose to go out). Furthermore, it might also trap free radicals inside the cell where they can do even more damage than they normally would. I should mention that the body has a mechanism for getting rid of free radicals and most of the time it does a good job. It usually manages to get rid of 99.99 percent of them, but it's the few that are left that are the problem.
Not only can the few that are left cause mutations in the cell, but they usually also attack the mitochondria of the cell. They are the "power stations" of the cell; in other words, they generate the energy needed to run the cell. So we obviously don't want things disrupted by having too many free radicals inside the cells.
This brings us to the question: Can microwaves cause cancer? And it's obviously a very important question. As we saw, several other types of radiations definitely can cause cancer, but what about microwaves? If you've followed the news over the last few years you've no doubt seen reports that there is no evidence that cell phone radiation can cause the dreaded disease. There is, however, a problem with most of these reports. As any scientist (who has worked on cancer) or statistician can tell you: there is no way that you can prove that microwaves, such as those emitted by cell phones, do not cause cancer. (One of my favorite books, in fact, is "How to Lie With Statistics," and most of the evidence is from statistical surveys). Microwaves may be low energy and incapable of ionizing atoms, but they are very penetrating and at high enough intensity, they can easily fry tissue. One of the major problems is that cancer takes so long to develop after it is initiated. It can easily take 20 years or more to make itself known. Although it may seem so, no one "suddenly" gets cancer. It has been festering and developing in their bodies for years.
Another problem is that the process that leads to cancer is very complicated (and I'd like to emphasize the word "very"). A single mutation within a DNA molecule in your body will not lead to cancer. If it did, you'd be in serious trouble, because thousands of mutations occur every day; fortunately most are repaired by your body --but not all of them by a long shot. Cancer is caused by a certain sequence or array of mutations, and unfortunately we don't know exactly what this array or sequence is. Certain genes are obviously more important than others in this respect, and they are the ones that turn cell division on and off. Basically, cancer is cell growth that has somehow got out of control, probably because a gene that was suppose to control it became mutation (but remember that each gene has approximately 100,000 DNA units in it).
It took years to show that smoking, and various carcinogens such as asbestos, caused cancer. Tobacco companies argued for years that if cigarettes were bad for your health the effects would show up within a few years, and there didn't appear to be any serious effect. Well we all know what happened to that argument. The effects did come -- it just took a little time. What is time going to tell us about cell phone radiation? And I'm not finished yet ... some of the most serious effects may come in something I haven't mentioned yet.
From what I've said so far, it might seem that the weak spot in our body for microwave damage is our DNA, but this is not necessarily true (but, of course, almost everything in our body is made up of DNA). Cell phone users hold their phones to their ears, with the antenna only a few inches from their brains, and everything that goes on in our body is controlled by our brain. Furthermore, it is controlled by electrical signals and to some degree by electromagnetic waves similar to microwaves. And one of the first things anyone learns in a physics class is that when electromagnetic signals and electical currents come together, they interact (and change).
We normally refer to the main signals in the brain as electrochemical signals because part of the transmission is a result of chemicals, nevertheless, most of the signal is electrical. Within the brain there are billions of nerve cells, with each of them reaching out to other cells to create an unbelievably intricate and complex network (much more complex than any electrical network in man-made electrical devices). Electrical and chemical impulses travel along these cables and allow us to think, learn, move, and sense the world around us. These nerve cells are called "neurons," and inside the neuron cell body is a nucleus and various types of biochemical machinery for maintaining the cell. Fibers called axions and dendrites extend out from the cell body; they are the cables that carry the electrrical messages.
But I said there are also waves similar to microwaves in the brain, and indeed, there are. We usually refer to them as "brain waves." They can be monitored using an electoencephlograph; it records what are called EEG's. The frequency of these brain waves depend on whether we are awake or asleep. They are named after the letters of the Greek alphabet: alpha, beta, gamma and so on, and their frequency varies slightly. When you are awake, your brain emits beta waves; they have a frequency of 8to 25 Hz. When you start to fall asleep your brain emits alpha waves; finally as you fall asleep, they change to theta waves of frequency 6 to 8 Hz. With deeper sleep they change to delta waves of frequency 1 to 3 Hz.
The one we are mainly interested in are the beta waves that are emitted when we are awake. As I mentioned earlier, electromagnetic waves interact, so we have to ask: Do microwaves interact with them? It's easy to see that there is a big difference in frequency (microwaves have a frequency of 850 to 1900 Mhz), so any interaction would be small (but it shouldn't be completely ignored). On the other hand, as it turns out, there are waves about the same frequency as brain waves that are emitted by cell phones. The first type is referred to as TDMA (Time Division Multiple Access) waves. All cell phones have a system that allows several users to share the same frequency channel by dividing the signal into different time slots. In this system the users transmit and receive signals in rapid succession, one after the other. In this way, more people can communicate with the base station simulataneously. The result is a low frequency pulsing of the signal at 8.34 Hz (which is very close to that of beta waves). The second type is referred to as DTX (Discontinuous Transmission) waves; they occur because cell phones use an energy-saving pulse transmission; when you are listening to someone, your transmission mode is turned off. It has a frequency of 2 Hz.
In recent years much of the interest in the brain and microwaves has been in relation to the blood-brain barrier. To understand this barrier we have to begin with blood vessels, in particular, capillaries. They are made from thin, flat cells called "endothelial cells;" these cells join together and roll themselves into long tubes that become arteries, veins and capillaries. Because of their structure, they are "permeable," in other words, they allow molecules of various types to get through (and restrict others). This is particularly important in the case of capillaries, which deliver nutrients to all parts of the body, and also carry toxins, bacteria and viruses away from the cell for disposal. In the brain the endothelial cells overlap each other creating a very strict barrier that allows light weight molecules through, but restricts all heavy molecules. This barrier protects the brain from chemicals and other harmful substances in the blood, but lets the light-weight nutrients and other needed molecules such as oxygen through. If problems occur in this barrier, the brain is susceptible to many different types of infection that can be serious.
Can micowaves affect this barrier? Studies in Sweden have shown that they can. In particular, one study showed that they can increase the permeability of the capillaries enough to allow albumin through (it normally doesn't get through). Other studies have verified the results.
Before I leave the brain I want to mention some studies briefly (several others will be discussed below). Several studies have been made on whether brain tumors occur more frequently near the ear where the cell phone is used and the result is that there is a definite correlation. Brain tumors do occur more frequently here.
As I mentioned earlier, there is still considerable controversy as to the danger of cell phones, and this is to be expected (the cell phone industry is huge -- hundreds of millions of cell phones are sold around the world every year). Many reports of studies have been published emphasizing that cell phones are safe, but in most cases they admit that more study is needed. The FCC, for example, issued the statement, "If there is a risk from these products ... it is probably very small." Other reports say "They appear to be safe ... but the final word is not yet in." On the other hand there are a large number of reports that indicate there may be a serious danger. The following is a sample of some of these reports.
In 20002 F. Marinelli of the National Research Council in Italy reported that microwaves similar to those from cell phones appeared to promote the growth of cancer cells. In particular he showed that after an exposure of 48 hours (which should have been a lethal) the exposed cells began replicating furiously. He suspected tht the radiation was damaging the DNA, which in turn, was causing the rapid increase in growth.
Dariusz Lesjczynski of the Radiation and Nuclear Safety authority in Helsinki, Finland, showed that one hour exposure to cell phone radiation caused human cells to shrink. Lesjczynski believes this could have a serious effect on the blood brain barrier.
David de Pomeria, a molecular biologist at the University of Nottingham, showed that there was clear evidence of non-thermal effects of microwave radiation on nemotode worms. When exposed to the radiation their fertility was increased, opposite to what would be expected from heating. Dr. de Pomeria believes that cell phone radiation can damage DNA indirectly without heating the the cell it is in.
Dr. Gerard Hyland of Warwick University in England published a paper listing numerous studies that showed that microwaves have a large range of non-thermal effects such as DNA strand breakage, chromosomal Aberration, and the promotion of cancer.
A Swedish report in 2006 from the National Institute for Working Life stated that people with 2000 hours of time on a cell phone had 3.7 times the risk of developing brain cancer compared to those that did not use cell phones.
Dr. Henry Lai, a bioengineer at the University of Washington, who has studied the effects of microwaves on cells for years, reported that brain cells are definitely damaged by microwaves at levels far below the government safety levels. He stated that 'radiation from cell phones may also damage DNA and cause cancer."
In 2001 a research group in Australia led by P. Finch showed that cell phone frequencies well below that accepted safety levels could stress cells in a way that could lead to cancer.
Children are at much higher risks than adults, and the reasons are numerous. To make things worse, children and young poeple are the fastest growing group of cell phone users, and the main ones being targeted by telephone companies. Even very young children now us cell phones daily.
One of the reason for their increased susceptibility is that they have much thinner skulls, and as a result the radiation penetrates to the brain easier. Furthermore, the absorption of radiation is greatest in an object about the size of a child's head because of "resonance." In addition, the nervous system of a child is still developing, and therefore it is more susceptible to the effects of radiation. This also applies to their immune system.
Finally, children are more susceptible because brain tumors usually take at least 20 or 30 years to develop, and they will be using cell phones over much of their life. Most adults will only be using cell phones over part of their life. Most countries (other the the US) are now recommending limited use of cell phones by children.
1. When using a cell phone, keep the antenna as far away from your head as possible. Extend it out and hold it away from your head. (Intensity of radiation drops off rapidly with distance.)
2. Limit the time of your conversations on a cell phone. Use conventional phones for long conversations.
3. Do not use cell phones in a car (the power is amplified considerably).
4. Check the SAR level of your cell phone (it varies from company to company). Make sure it is as low as possible.
5. Stay away from cell phone communication towers.
6. Keep your distance from people talking on a cell phone (it's like second-hand smoke).
Background on Barry Parker Ph.D.
Taught electromagnetic theory for 30 years at undergraduate and graduate levels at university .
Research on quantum tunneling and mutations in DNA including several scientific papers.
Taught biophysics for several years at university.
Author of "Feel Great Feel Alive" and 22 other books.
website: BarryParkerbooks.com
