Electromagnetic Fields & Cancer Myths
Posted by mattusmaximus on April 2, 2009
Every year when I teach my students about electromagnetism, I take some time to discuss with them the physics of electromagnetic waves (a.k.a. “light”). EM-waves go by another name common to scientists, electromagnetic radiation, and it’s that second word – radiation – which scares the hell out of so many people and makes them vulnerable to all manner of woo.
Case in point, there is a lot of bunk out there concerning EM-radiation and cancer. Specifically, there is a group of folks who try to push the idea that cell phones, power lines, and wi-fi are emitting radiation (called EMFs, or electromagnetic fields) which will give people exposed to them all manner of cancers. I’m here to tell you that this is just plain b.s. – people who make these pseudoscientific arguments do not understand the physics of EMFs, at all.
First off, the physical mechanism which creates an electromagnetic wave (or “EM-radiation” or “light” or “EMFs” – they’re all the same thing) is basically wiggling an electric charge back and forth. This process generates a self-reinforcing set of electric & magnetic fields which form the wave, and the frequency of these waves (which matches the frequency at which the charge is wiggled) is what determines exactly what kind of EM-radiation is created. Depending upon the frequency of the wave, it will fall along what is called the electromagnetic spectrum…
So everything from radio waves to visible light to x-rays is a kind of EM-radiation. The only difference between these kinds of radiation is the frequency of the wave.
Here’s where the trouble starts. As I mentioned earlier, some folks think that the EM-radiation emitted by cell phones & power lines causes cancer. The problem with this argument is that the radiation emitted by devices such as cell phones is not what is called ionizing radiation – which is EM-radiation that is energetic enough to smash into DNA, break it apart, and cause cancer.
E = hf
where E is energy, f is frequency, and h is called Planck’s constant. Note that as the frequency of the photons increases, so too does the energy – and this is the critical detail.
In order for EM-radiation to break the chemical bonds of DNA molecules (and thus cause cancer), there must be a certain minimum level of energy provided by the incoming photons. It ends up this is not physically possible for photons of energies less than the ultraviolet (UV). Note that when you hear warnings about getting skin cancer, it is because you may be getting too much UV from sunlight; when you go to the dentist for an x-ray, they make you wear a lead apron to dilute the x-ray exposure; and you don’t even want to mess with gamma radiation, which is so high energy that sufficient exposure will kill you due to radiation poisoning.
Looking at the diagram posted above (the EM-spectrum), note that all of these nasty forms of dangerous, ionizing radiation exist on the high frequency, high energy section of the spectrum. This is important because when you talk about the emissions coming from cell phones, power lines, wi-fi, and so on, these forms of EM-radiation are in the radio wave region, which is the low frequency, low energy band. And because of the formula governing the energy of photons (shown above), it doesn’t matter how many of these low-energy, radio-frequency photons emitted by cell phones hit you in the head, you still won’t get cancer.
In addition, if you want to go past the fact that there is no known physical mechanism by which cell phone, power line, and wi-fi radiation could cause cancer, there are the medical studies. For example, as the Skeptic’s Dictionary states…
Many people fear that EMFs cause cancer; however, a causal connection between EMFs and cancer has not been established. The National Research Council (NRC) spent more than three years reviewing more than 500 scientific studies that had been conducted over a 20-year period and found “no conclusive and consistent evidence” that electromagnetic fields harm humans. The chairman of the NRC panel, neurobiologist Dr. Charles F. Stevens, said that “Research has not shown in any convincing way that electromagnetic fields common in homes can cause health problems, and extensive laboratory tests have not shown that EMFs can damage the cell in a way that is harmful to human health.”*
In closing, I wanted to leave those who still fear cell phone and similar radiation with this thought: you are constantly bathed in electromagnetic radiation of higher frequency & energy every time you turn on a lightbulb or take a walk in the sunlight. It’s called visible light (wavelength 400-700nm), and if you are honest in your fear of EM-radiation, then you might want to be certain to live the rest of your life in the dark. You know, just to be safe in keeping with the Paralyzing Precautionary Principle.