Electromagnetic Radiation at Home

Given the various household technologies that people have come to embrace, there’s a growing concern over the electromagnetic fields that household appliances emit. And since household appliances are consistently in use, the common apprehension is that people’s exposure to electromagnetic radiation (EMR) is also as consistent, sadly without the victims knowing it. The biggest fear is for EMR exposure to cause cancer.

Household EMR doesn’t make you ill or give you cancer. Here’s why: People suffering from electromagnetic hypersensitivity are ill. But when you look at the evidence, it’s not electromagnetic radiation that’s the problem.

There are few phenomena as ubiquitous or vital to human existence as electromagnetic radiation or EMR. It permeates everything we experience, be it the visible light illuminating all we see, or the broadcast media transmitted across the globe by radio wave. In medicine, X-ray and gamma rays have revolutionized both anatomical imaging and treatment for cancer.

In the era of wireless communication, our phones and routers take advantage of microwave radiation to rapidly convey virtually the entire repository of human knowledge to our fingertips at staggering velocity.

But while EMR is an inescapable part of our universe, there are many who worry about potential detrimental effects. In particular, the propagation of personal communication devices has been a source of concern to many. There are those who claim to suffer from a condition called electromagnetic hypersensitivity (EHS or ES), whose symptoms include everything from fatigue and sleep disturbance to generic pains and skin conditions. More still fixate on idea that today’s increasingly wireless offices and homes might amplify people’s cancer risks. Such narratives are common and understandably disturbing. But should we be concerned?

It’s important to clarify a few potential sources of confusion. Radiation itself is a deeply misunderstood term, frequently conjuring up worrying associations with radioactivity in the public consciousness. But radiation simply refers to transmission of energy through a medium. In the context of EMR this means radiant energy released by an electromagnetic process.

The electromagnetic spectrum is the range of all possible frequencies of EMR, where energy is proportional to frequency. Some of these have sufficient energy to eject electrons from an atom or smash apart chemical bonds, which renders them capable of causing DNA damage. This is known as ionizing radiation, and this ionizing potential is exploited when X-rays are harnessed to kill tumor cells in radiotherapy.

This fact can make people uneasy – if light can be used to destroy cells, could our heavy usage of wireless communications perhaps induce this kind of DNA damage and ultimately lead to cancer? This is reasonable to ask, but we have to keep in mind how unbelievably vast the electromagnetic spectrum truly is. Modern communications, from our Wi-Fi networks to phones, are firmly rooted around the microwave end of the scale, consisting of relatively low frequency and low energy. To put this in perspective, even the lowest energy visible light carries roughly 1430 times the energy of the most energetic microwave photon. Microwave radiation is undisputedly non-ionizing, and completely incapable of direct DNA damage.

In spite of their low energy, microwaves are remarkably effective at heating certain substances through a process known as dielectric heating. Domestic microwave have an electric field that cause polar molecules to rapidly bump off each other as they try to align to the rapidly changing field. The friction from these rapid collisions is converted to heat, which is precisely why microwaves are so efficient at cooking our predominantly waterbased food.

This seems to get many people confused. Selfprofessed experts assert that microwave cooked food is harmful by being exposed to radiation. But this is wrong-headed: microwaves are not radioactive and do not “irradiate” food – they merely harness vibrational energy to heat it.

Other lines of dubious reasoning rely on misguided extrapolation: if microwave ovens can cook meat, then our Wi-Fi routers and cell phones are therefore cooking us too. But while thermal effects are certainly possible with microwave radiation, the power output of our communication technology is many orders of magnitude below that of ovens, with typical home routers outputting less than 100mW. On top of this, ovens are designed to concentrate high power microwave radiation using specially designed waveguides, magnetrons and reflective chambers, a situation neither encountered nor desirable in our conventional communication technology.

It’s important too to note that the intensity of an approximately spherical source of electromagnetic radiation has an inverse square relationship with distance. For example, the field intensity a meter from an EM source will be 4 times greater than the intensity 2 meters away, and 9 times greater than a measurement taken 3 meters away from the source. In practice, this means the strength of an EM source diminishes enormously even over modest distances.

Of course, our cell phones by definition come into very close contact with our heads, and so avoiding thermal ill-effect is a major consideration. The heat energy absorbed by tissue exposed to an EM field is given by the specific absorption rate (SAR). In the European Union, the maximum exposure to EM fields is tightly regulated to a maximum of 2W per kilogram, averaged over the 10g volume receiving the most direct heating to circumvent thermal effects. Importantly, dielectric heating only increases tissue temperature and will not by itself cause any damage to DNA bonds, so SAR should not be taken as a proxy for cancer risk.

To date, there is no evidence that mobile phone usage increases cancer risk – The World Health Organization states that “no adverse health effects have been established as being caused by mobile phone use.” Even long-term studies of radar workers show no signs of increased lifetime cancer incidence, despite their exceptionally high levels of exposure to microwave radiation.

But cancer fears are only one aspect – claims of allergic-like responses to EMR are commonplace, again expounded by self-professed experts. Such is the extent of belief in EHS that there are numerous dedicated support groups, and inevitable legal action. Yet despite the sincerity of these beliefs and the discomfort experienced by sufferers, the inescapable reality is that there is zero evidence supporting their position.

In provocation trials, sufferers have been completely unable to identify when sources of EMR are present. Subjects also reported negative effects even when exposed to fake EM sources. These results have been replicated in a number of trials, strongly suggesting that the illness sufferers feel is psychological rather than physical, and that for some the belief one is allergic to EM radiation is enough to trigger an unpleasant psychosomatic reaction, although sufferers experience a very real discomfort.

As always, we have to be wary, and be guided by best evidence rather than panic. Most EMR is invisible and inescapable, and apprehension over what we cannot see is completely understandable. But if we are to make informed decisions on health and technology, misplaced fear of the unknown or dogmatic convictions are simply no substitute for evidence and understanding.