It’s the myth that simply won’t go away. Since the introduction of mobile phones and related technology, it has been held responsible for a wide range of ailments and afflictions. Men’s testicular cancer, brain tumours and heart cancers in particular have been linked, incorrectly to increased use of mobile technology and the radio frequency electromagnetic radiation (RF) it depends on. This is despite very simple physics which shows that the type of signal used by mobiles, can’t cause cancer.

The latest media report of the mobile/cancer link comes from the Observer in the story ‘The inconvenient truth about cancer and mobile phones’ published on 14th July. To tackle exactly what the story gets wrong and why mobile phone radiation is extremely unlikely to be carcinogenic it’s important to break the analysis of this concern into two parts.

The report focuses on a study by the National Toxicology Program of the US Department of Health and Human Services, which concerned the exposure of rats and mice to radiation similar to that produced by mobiles. So an investigation of this study and highlighting what the reporters may have misunderstood is vital.

But before tackling this, it’s actually helpful to first lay out the groundwork of what mobile phone radiation, RF, actually is and in doing so, what makes it fundamentally different to forms of radiation which are known to cause cancers. A difference that isn’t even touched on in the article.

#Not all radiation

Put simply, the type of radiation used by mobile phones and wi-fi signals is non-ionising. It doesn’t have the required energy to strip electrons away from atoms. This is what distinguishes it from ionising radiation like ultraviolet radiation, x-rays and gamma-rays, which do meet these energy requirements.

Ionising radiation is associated with nasty ailments like cancers because of how electrons fundamentally determine chemical interactions. These interactions are crucial in the folding of proteins, thus if the interactions are ceased or changed, mutations are caused. It’s these cell mutations which can cause cancer.

Claims surrounding such forms of communication normally concern the ideas of “radiation” and the negative connotations surrounding that word that have been lingering since the atomic age.

In reality, we’re constantly surrounded by electromagnetic radiation. Most of it non-ionising. A simple understanding of physics dispels any idea that electromagnetic radiation of the type used for Wi-Fi and mobile phone signals could cause cancer, even in cases of prolonged exposure. To understand why such things as Wi-Fi and mobile phone signals are not to be feared it’s necessary to take a look at the electromagnetic spectrum.

Figure 1: The electromagnetic spectrum

The electromagnetic radiation used in Wi-Fi and mobile phones exists in the long wave section of the above diagram, between radio waves and microwaves. As an electromagnetic signal’s wavelength shortens its frequency increases according to equation 1 (below) where c is the speed of light, f is the frequency and λ is the wavelength.

You’ve likely been told that light is both a wave and a particle, but a nit picky physicist will tell you that’s only loosely true. Light can be described by both a wave model and a particle model, and a wave-packet, or a quanta (hence quantum physics) of light more commonly called a a photon. The energy of this packet is given by equation 2, where E is the energy and h is Planck’s constant.

As both the speed of light c and Plank’s constant h are unchanging (constants) it should be clear from the above that as the wavelength ( decreases the frequency increases. In turn, as the frequency increases the energy of the light also increases. So clearly the right side of the figure 1 represents high-energy, high-frequency electromagnetic radiation. This is high energy radiation is also known as ionising radiation. When photons interact with an electron in an atom, they are often absorbed and the electron, which can only occupy an allowed orbit with an associated energy value, moves up to an excited state. If the supplied energy is sufficient the electron escapes the atom altogether, the atom is ionised in other words.

Figure 2: The required energy of ionise a atom of hydrogen.

So you can see from figure 2, the ionisation energy of an electron in the ground state around a hydrogen nucleus is 13.6 eV. Larger atoms have larger ionisation energies, which is simple to understand, more protons in the nucleus mean a stronger positive charge and therefore a stronger “pull” on the negative electrons ( for simplicity I’m ignoring an effect known as shielding which prevents this from being a strictly linear relationship). Electrons are far more likely to be found in a ground state than an excited state, as electrons in such a state quickly emit photons of the necessary energy to drop down to a lower excited state or the ground state.

So let’s see if a photon of the electromagnetic radiation found in Wi-Fi signals is sufficient to ionise hydrogen.

This is the photoelectric effect discovered by Einstein and explained why increasing intensity of light shining on a metal doesn’t increase the yield of electrons despite the increase in photons. Not just any photon will do. It has to have the correct energy value. Ionising radiation can indeed lead to cancer and other health problems arising from damaged DNA, but we’ve seen above, Wi-Fi signals are far from ionising.

So what about mobile/cell phone signals? They tend to have a wavelength of roughly 30 cm or 0.3 m so have a corresponding energy of 0.000004 eV, even further away from ionising even the loosest held electron.

Everything I’ve listed above is resolutely ignored in the Observer article. The author doesn’t mention non-ionising radiation once. Thus, there’s no attempt to ensure that readers understand the distinction between ionising and non-ionising radiation.

“Lack of definitive proof that a technology is harmful does not mean the technology is safe, yet the wireless industry has succeeded in selling this logical fallacy to the world. The upshot is that, over the past 30 years, billions of people around the world have been subjected to a public-health experiment: use a mobile phone today, find out later if it causes genetic damage or cancer.”

From the above statement it seems clear that for this author, physics doesn't even seem to be a consideration. Before citing a lack of evidence, one must first consider the wealth of evidence there is regarding the underlying science, of which there is a lot. Our understanding of electromagnetic radiation is extremely comprehensive. Comprehensive and ignored here.

So what does the author concentrate on?

So why did the Observer conclude that mobile phones can cause cancer?

Firstly, it’s vital to point out that the study which forms the foundation of the Observers report concerned rats and mice not human subjects. Whilst the paper is correct in pointing out that there are many biological similarities between ourselves and rodents, they fail to point out that there at least as many dissimilarities.

In a 2009 study published in the Journal of the Royal Society of Medicine Michael B Bracken points out that studies using animal cohorts are often extremely poor predictors of health effects in human beings. This is especially true when the studies concern environmental and medicinal agents. Bracken states that studies should not be considered evidence of similar effects in human beings until they have been replicated successfully with human subjects.

In the specific study that the Observer cites , the rodents were subjected to extremely high doses of non-ionising radiation for nineteen hours a day, for every day of their two year lives. This this far higher than even the most phone dedicated human being would be exposed to. The chambers that the rodents were kept in also ensured that their whole bodies were also exposed to this level of radiation.

An examination of the study this report centres around reveals that it was only the male rats who were exposed to the highest levels of RF who displayed a higher incidence of cancers than expected. There was no statistically significant effect in the female rats or any of the mice exposed to the low-frequency electromagnetic radiation. In those groups, the tumour incidence was the same as that shown in rodents not exposed to the radiation.

“The levels and duration of exposure to RFR were much greater than what people experience with even the highest level of cell phone use, and exposed the rodents’ whole bodies. So, these findings should not be directly extrapolated to human cell phone usage,” said John Bucher, Ph.D., NTP senior scientist.

Yet, the Observer directly ignore the advice from the study’s senior author instead focusing on a peer-review group which concluded that the study showed “some evidence” that non-ionising radiation may have led to an increased incidence of heart-cancer in male rats. They also ignored several other peer-review panels that examined the study and concurred with the conclusions of the study’s authors. It should also be noted that the designation “some evidence” is equivalent to the dreaded “more research is required”. It basically tells the reader that no solid conclusion as been reached.

The Observer article implies that groups that have previously examined this and other studies and found them inconclusive or no cause for concern, have been strongly influenced by the “wireless” industry. A paranoid claim that is unsupported by any conclusive evidence.

The article points out that absence of evidence is not evidence of absence. Just because there isn’t conclusive research that shows a causal link between mobile phone use and cancer, doesn’t mean it isn’t there. This isn’t how science is done, if “mobile phones cause cancer” is the alternative hypothesis laid out by a study then the null hypothesis is “mobile phones don’t cause cancer”. If significant evidence is not found for the former, then the latter is held to be true.

Also, what the author ignores here is the fact that there is no known mechanism for non-ionising radiation to cause cancer. This should be weighted against studies that seem to have found a weak causal link.

What we also have to consider is that if there was a causal link between cancers of the type identified in the article and wireless technology, we should be seeing a similar increase in incidence of these cancers as we are to the proliferation of this technology. Tumour rates in the heart and brain are tracked carefully in Europe and the United States and are not significantly increasing.

In fact, the rate of brain cancer rates in western countries has been extremely stable over the past few decades and remains extremely low. For example, the rate of brain cancer in the US is 6 in 100,000. Compare this to breast and prostate cancers which have incidences of 125 in 100,000 and 20 in 100,000 respectively.

Whilst the fact that brain cancers are not on the rise yet mobile phone and wireless usage is, doesn’t prove that non-ionising radiation can’t cause such cancers, that there has been no rise during the explosion of wireless technology should at least be considered then weighting the possibility of a causal link.

Oh Yeah… but other scientists disagree!

One of the other interesting elements of the article is the allegation that the wireless industry are using their influence to keep the question of the health risks of mobile technology open.

“ Funding friendly research has perhaps been the most important tactic, because it conveys the impression that the scientific community truly is divided. Thus, when studies have linked wireless radiation to cancer or genetic damage — as Carlo’s WTR did in 1999; as the WHO’s Interphone study did in 2010; and as the US government’s NTP did earlier this year — the industry can point out, accurately, that other studies disagree.”

The difficulty with this insinuation is that the studies that show a causal link are the outliers, the majority of studies show no link between low-frequency radiation and cancer incidence. The author in the above statement attempts to poison the well. The studies that found no causal link must be “friendly research”. And if it’s funded by the industry, well it should be dismissed entirely apparently.

This is an insult to science in general and the researchers involved in those studies in particular. If they obtained results the author didn’t like, they must be in collusion with “Big Wireless”.

The fact of the matter is the vast amount of studies into the connection between mobile phone usage and brain cancers have shown no causal link. When a paper does come out which implies there may be a link, it receives a disproportional amount of media attention and has undue significance placed on it.

The author implies that this interference creates the illusion that science is divided, when in fact it is united in the belief that wireless radiation is dangerous. To support this point he points to a petition launched in September last year to oppose the launch of new 5G technology.

The author seems to think that the 236 scientists who have signed the petition (it’s actually closer to 180) represent a major ground swell against wireless technology. To really consider how much support this idea has in the scientific community, bear in mind that there are approximately 7 million working scientists in world. CERN estimates that there are at least 24,000 particle physicists alone. That means that even using the Observer’s inflated estimate, less than 1% of just the particle physicists have signed this petition.

So if this is meant to show there is consensus about non-ionising radiation and potential cancer links, surely it demonstrates that the consensus exists very much in opposition to the author’s position.

The petition argument is similar to that once used by the creationist movement to oppose the theory of biological evolution by natural selection, which they refer to as ‘Darwinism’. The Discovery Institute first published their ‘Dissent from Darwin’ list in 2001 and it quickly rose to 514 signatures from working scientists and PhD holders. Currently it has over 1000 signatures.

Support for the idea that dinosaurs lived amongst men and even travelled on Noah’s ark has more support in the scientific community than the idea that RF causes cancer. That’s if we take petitions seriously… which we shouldn’t.

Now, science should never be done by popular vote, so a petition amongst scientists shouldn’t really mean anything. But…if we place as much importance on surveys and petitions as the author of the Observer piece does, then over four times the number of working scientists oppose Darwinian evolution as believe wireless technology to be a hazard.

What about WHO? WHO? Yeah WHO? WHO?

There is of course, the small matter of the World Health Organisation (WHO). They categorise mobile phones and wireless technology as a ‘Category B’ or ‘possible carcinogen’ cancer risk. Surely this means there must be some validity here?

WHO classify electromagnetic radio frequencies as a category 2B carcinogen. This means that they hold the position that it could be a carcinogen and that more research is needed to explore a possible causal link.

When WHO reviewed the body of work into the subject they decided there was limited evidence to suggest a link between RF and certain types of brain cancers and inadequate evidence to draw a link between RF and other forms of cancers.

It may put your mind to rest to hear some of the other substances that share the category 2B classification with RF radiation. These include piercings, coffee, gasoline, dry-cleaning and one for the ‘all natural’ advocates, aloe-vera!

I don’t see an Observer piece demanding to know why the cancer risks of aloe-vera are being covered up by ‘big nature’ coming any time soon.

Cutting through the hysteria

Moving through all the studies, the interpretations, the accusations, the money, governing bodies, the fear and the hysteria and focusing solely on the physics laid out at the start of this article, there is no physical mechanism by which low-frequency radiation can cause cancer.

Authors of articles such as this often neglect to reach out to the scientific community for differing opinions to their own and they almost never stop to ask a physicist. My advice, pick up the phone and call someone who studies physics to ask them about this.

As they will likely advise you. It can’t hurt.