Modern technology uses a lot of electrical and field energies. Mobile phones, phone masts, power lines, wireless networks are all human technologies that involve field-effects. All these technologies use the electromagnetic spectrum. All energy, in fact, exists somewhere on that spectrum, including visible light, micro waves, and dangerous high-energy gamma radiation. Some people fear the effects of electromagnetic radiation on the human body (I assume they are not afraid of light, though), and this text is about that fear.
Fear about mobile phone masts, power cables, and communications equipment in general is generally misguided, but, perpetuated by sensationalist newspapers, and occasionally by mass hysteria. Partially as a result of these fears, scientists have investigated the effects of electromagnetic radiation in great depth. EMF radiation connects all forms of radiation - X-Rays, ultraviolet rays, gamma radiation, radio waves, microwaves: these all have different frequency ranges, and scientists have studied the effects of all of them on living things. Over 25,000 articles have been published in the last 30 years and no risks have been found to result from exposure to fields associated with everyday human technology. Major scientific bodies including the World Health Organisation, the EU, and the American FDA and CDC have all come to similar conclusions.
We know exactly which areas of the electromagnetic spectrum are harmful (ultraviolet rays, gamma radiation, extended exposure to x-rays), and much of the rest of it is safe and has no effect on our health. The energy in the photons that make up a mobile phone's (and mast's) radiation is a million times lower than the radiation you are bathed in from natural yellow light from the sun, and, are also much less likely to interact with anything in your body. Ultraviolet rays from the sun cause skin disease as they are absorbed, but, mobile signals travel through walls and everything else, so do not get absorbed by the body - and when they do get absorbed, the energy is still 1 000 000 times lower than the energy of yellow light.2
A continuous fear of something, or expectation that it is bad, can cause symptoms that are called 'psychosomatic' because they are caused by the mind. Such symptoms most prominently include headaches, nausea and rashes. These are also the most common symptoms suffered by those who believe that radio masts, mobile phones, etc, are causing them harm1. Neophobia is an additional psychological factor that comes into play, where people fear new technology. Evidence for neophobia is that people protest against putting mobile phone masts near schools (which is safe) but happily take their children to a beach under the sun (where ultraviolet rays cause skin cancers). Scientific reassurances don't tend to work with some people, because they lack understanding of the underlying physics. The best cure for psychosomatic illnesses and neophobia is education and understanding, a process that is unfortunately hindered by sensationalist papers and general scientific ignorance.
These links contain further discussions on some of the concepts alluded to above:
These negative feelings are not only the result of mass hysteria, neophobia or other subconscious patterns. Sometimes they are the result of public relations campaigns and politics. An article in the Skeptical Inquirer traced the history of a few hoaxes concerning mobile phones:
“In June 2009 a new urban legend was born - that the power generated by cell phones can cook popcorn. A series of videos on YouTube appeared to show four users popping a table full of corn kernels simply by points their ringing phones at them. [...] The media has been reporting for years on alleged links between cell-phone usage and brain tumors, and alarmist headlines continue to excite the public regardless of the facts. As far back as 2000, spoof videos were being created of eggs being cooked by cell-phone power. The creator of the first of these, electronics expert Charlie Ivermee, created his video to poke fun at media scare stories but was surprised when it was taken seriously. [...]
So who would benefit from pandering to public concerns? [...] The brains behind the popcorn video had another motive: profit. Cardo Systems describe themselves as "an established world leader in the field of wireless Bluetooth communications." In other words, they make the wireless headsets that help you avoid putting your mobile phone to your ear. [... The creative team at Cardo] exploited existing concerns about cell-phone radiation and made them legend. [...] Cardo claims that traffic to its Web site doubled in the days the videos were active. [...] For those wondering, the secret of the video is mundane. Popped kernels were dropped onto the table as the phones rang, and the unpopped kernels were simply edited out. [...] Viewers may have their own motives for purchasing a headset, but if reducing cancer risk is one of them they should perhaps consider themselves misled.”
Tracy King (2009)3
A whole host of weird and wonderful products always manifests itself around irrationality, and mobile-phone-radiation fear is no exception. Because the symptoms are caused by the mind rather than by reality, 'cures' that work simply by reassuring the user that they are protected tend to work to reduce and remove those symptoms. Tricks of the mind can cure tricks of the mind, but the result is that quack remedies often have followers who go around telling everyone else that some ridiculous product actually works.
“A growing industry of fraud artists is taking advantage of the fact that many of the supposed symptoms of EMF appear to be psychosomatic. They are offering a broad variety of quack remedies that will absorb "harmful" EMF or otherwise shield the user. These products range from pendants worn around the neck to a patented $727.50 "i-H2O activator" that "structures all the water you use."”
The industry is fuelled by confusion and irrational fear, but, the existence of these gadgets furthers public concern. Some of the producers might also think their own gadgets work, but it would be better for all if industries such as these shut-up shop. The surest way to achieve this aim is to educate people about the futility of their products, and educate people more on the physics of electromagnetic radiation, and of course, improve sceptical thinking in general.
There are three ways that electromagnetic radiation can cause harm within to living bodies. Each effect is particular to a certain range of frequencies1. Our main exposure to dangerous electromagnetic radiation is from direct sunlight.
|Induced voltage gradients|
|Low frequencies (0-3 KHz)||Magnetic fields might do weird things to our bodies.||Normal human technologies do not produce frequencies in this range, and, the Earth itself has a magnetic field.|
Absorption causes heating
|30 MHz - 300 GHz|
|Absorption of energy causes heating, which if enough happens at once, can damage tissue.||Energy has to specifically and intentionally focused to have an effect.|
Molecules are damaged
|Ultraviolet light, X-rays, gamma rays||Carcinogenic due to occasional DNA damage.||We are exposed to these from space and from the sun, but not from human technology.|
“Extensive scientific testing has been used to measure these effects and to establish safe limits. [...] In the U.S., FCC regulations set limits on permitted exposure for the public at 1/50 the level at which harmful heating effects may occur. Actual exposures are hundreds to thousands of times lower. The photon energy of a cellphone EMF is more than 10 million times weaker than the lowest energy ionizing radiation.”
In order to understand more deeply the fact that damage from these types of radiation is not due to chance but due to near impossibility, more needs to be explained about the nature of radiation and photons. I would rather quote from a suitable expert rather than attempt to explain the physics myself, so, firstly, understand that all forms of electromagnetic radiation is made from photons, which are the fundamental waves/particles that make up all energy:
“All electromagnetic radiation consists of small particles called photons. The energy of a photon is determined by a formula called Planck's law: the energy of the photon increases as the frequency increases. Now consider a photon of yellow light. This has a frequency of some 5x1014 Hz. The energy of such a photon is approximately 2 electron volts [...]. If there is an increase in the power, only the number of photos increase, not its energy. Thus, a standard yellow sodium lamp with higher power rating provides more light with more photons, but each photon still has exactly the same amount of energy.
A typical cell phone uses a frequency of 1x109 Hz. The frequency used in a household microwave oven is 2.45x1012. Therefore, the energy of photons in these sources will be lower than that of yellow light by a factor of a thousand for the microwave oven and a million for the cell phone. The frequency of a standard 60 Hz power line will be further lower by a factor of one million. Roughly one million photons in a power line together have the same energy as a single photon in a microwave oven, and a thousand microwave photons have the energy equal to one photon of visible light. [...]”
These photons, which en masse make up electromagnetic radiation, are absorbed by the atoms that make up all biological matter. The frequency of the radiation determines what method of interaction is important.
If the frequency of electromagnetic radiation is high enough, photons will have enough energy to ionize atoms, i.e., to interact with electrons or protons and therefore interfere with molecular structure. This becomes possible at a frequency just above that of visible light - ultraviolet light, and includes gamma radiation and x-rays. None of them are produced routinely by human technological gadgets.
Gamma rays are found in space, and as the result of radioactive decay and nuclear reactors and atom bombs.
X-rays, like radio waves, pass through most material without any interaction at all, and are unlikely to cause any cellular damage. This is why they are safe to use on patients in hospitals. There is the chance, however, that rare interactions could damage cells or DNA (something that radio waves cannot do), which is why medics (and dentists) who use X-ray equipment frequently have a screen they stand behind to reduce constant exposure.
What we are exposed to all the time is ultraviolet light. The sun produces this and the Earth's surface is bathed in it. It has a slightly higher frequency (and therefore higher energy per photon) than light, and is absorbed by most substances, including skin. It is one of the most common causes of cancer and skin problems.
The way that ionizing photons cause cancer is as follows. DNA is the famous double-helix chemical strand that controls how our cells manufacture proteins. It is a delicate process. DNA is held together by chemical bonds, the same as all other molecules are. High energy photons can knock electrons out of their orbits, or sometimes interact with the nucleus of an atom. To do this, the frequency of the radiation has to be high enough. It can then damage the DNA. If the frequency isn't high enough (mobile phones and radio waves are not), then, the radiation cannot cause ionization no matter how much of the radiation there is. Even when it is absorbed it is rarely cancerous. Most the time, because of the double-helix structure and various cellular mechanisms of DNA monitoring, the damage is repaired. It is very unlikely that photons happen to hit DNA in a cell (a cell is very large compared to the size of the DNA in the nucleus). It is also rare that when a photon hits DNA that it causes any lasting damage. And if a cell goes wrong, it is also rare that this causes the cell to turn into a cancer as most genetically damaged cells are either destroyed or self-destruct (apoptosis).
Because of the negating factors, it requires continued exposure to high doses of appropriate radiation in order for cancers to be caused. The sun, being a massive nuclear reactor (333 thousand times more massive than the Earth), is one such source. Compared to everyday exposure to ultraviolet light from the sun, no everyday human technology poses a comparable risk, and in addition, the frequencies used by telecommunications equipment is simply not high enough to be ionizing, no matter what strength of signal you are exposed to.
Ionizing radiation can be dangerous due to the occasional chance of molecular damage to cells. Some other (lower) frequencies of the electromagnetic spectrum are dangerous not because they knock electrons out of orbit, but, because they are absorbed by liquids and cause heating. In a microwave oven, it is generally water that absorbs the emitted photons. The temperature required to do damage to us is generally rather high because in our bodies, liquids are generally full of long and heavy biological molecules that raise the heat capacity of the liquids.
European worry-worts are often criticized for their hindering of European industry with health and safety red-tape. It sometimes seems that these beaurocrats, and those staffing international bodies, go out of their way to find unlikely dangers in products. Yet despite their best efforts (over 25 000 articles have been published), the scientists have found that this time, there is no threat. Communication masts, mobile phones and power lines do not interfere with human health.
The World Health Organisation in its 2004 report "What are Electromagnetic Fields: Health Effects" recorded that 25 000 articles have been published on the effects of EMF radiation in the last 30 years. It stated authoritively that there is no evidence from these studies that the electric fields we are exposed to by masts have any negative effects on health.1
The European Parliament's scientific advisory body (SCENIHR) released a comprehensive new report in 2009 entitled "Health Effects of Exposure to EMF" and concluded that not only is there no likely risk from the new uses that we find for radio waves, but, modern base stations are more efficient and emit lower-intensity radiation than old-style broadcast transmitters on which extensive tests have already been done.1
The FDA and the CDC in the USA have come to similar conclusions, as have "most of the world's major national public health organizations"1.
One collaborative report has found that there are serious health risks, but this report is itself considered to be poor quality science:
The Bio-Initiative Report was composed by "a minority of scientists [who] have helped fuel the hysteria. Yet the Bio-Initiative Report has been widely criticized in the scientific community for promoting only poorly conducted studies that support its alarmist views while ignoring far more rigorous and comprehensive studies that show no danger"1.
In order to have any chance of causing cancer, electromagnetic radiation has to be of a high enough frequency so that it can ionize atoms, as I have explained above. Even if such a photon is absorbed, the chances of it causing cancer are miniscule, but, it still does happen. The frequencies used by human technological gadgets are well below the frequency at which ionization occurs. The frequencies used by mobile phones are one million times too low to have enough energy to cause ionization. If you stood next to the world's most powerful mobile phone or mast, you would merely be exposed to a larger dose of non-ionizing radiation. The risk does not come from the power levels of the signal. To make a mobile phone's radiation ionizing, you need to increase its frequency by a million times, not just boost its power (which leaves the frequency the same). Obviously, no mobile phone is powerful enough to do this (and it would no longer be using radio waves). In fact, no gadgets use frequencies that are ionizing.
Is this all really true? We know that we have the physics right, because, in the last century we started pumping out massive signals from broadcast antenna at a strength many times higher than mobile phone masts have ever used. Also, we are all exposed to a constant and dense fog of electromagnetic radiation from telecommunications equipment (some call it 'electrosmog'). And as our use of radio waves has diversified and increased in the modern world, cancer rates have fallen. Modern telecommunications technology does not cause cancer.
Another way to look at it is to consider the efficiency of mobile phone to mast communication:
“The easiest way to recognize this extremely poor interaction between very low-energy photons associated with the radio frequency (RF) in cell phones and molecules is to remember that the small amount of power being transmitted by the phone is traveling several kilometers to the tower. [... It] passes through several walls and other obstructions, even people, without impeding the communication. This explains that usual statement that the power levels in these situations are well below the limits set for exposure to RF sources. As for the typical 50-60 Hz power lines, the photon energies are too low for any meaningful interaction with atoms. [...]
It is simply not possible for the photons associated with either a power line or a cell phone to cause cancer. [...] The presence of power lines can spoil the view, can lower market value, or even psychologically irritate one, but there is simply no reason to worry about cancers of any variety from their presence.”
Skeptical Inquirer. Pro-science magazine published bimonthly by the Committee for Skeptical Inquiry, New York, USA.