I had an interesting conversation with a friend today about electromagnetic fields (EMFs) and the potential health risks they represent. This is just the type of topic which interests me so I decided to do some research on the subject.
What are EMFs?
Prior to my research, I was under the impression that EMFs were magnetic fields created by electricity. After doing some research, I think my understanding was technically correct, I've learned that there is definitely more to the story.
The National Cancer Institute at the U.S. National Institute of Health define EMFs as "Electric and magnetic fields", not "electromagnetic fields" [1].
I had previously thought that since magnetic fields have been around since the dawn of time, we'd know by know whether or not they present a risk to our health. While I can't say the same about electricity, I still have to question my logic there, as the sun has been around as long as the sun, but we still question how much exposure to it presents a risk.
Anyway, back to EMFs, electricity and magnets. I've heard rumors that some people believe that exposure to magnets has health benefits, and am under the impression that some medical procedures involve electric currents and even electric shocks. What about the two together?
Magnetic Fields
Now that I am reading up on the topic, I'm starting to get the notion that the term "magnetic field" has a broad scope. To explain this notion, I'll compare magnetic fields to light. The fields created by a magnet might be similar the light of a firefly. Both are natural and as far as I am aware, don't cause harm to humans.
While the light of a firefly doesn't pose a risk, there are types of light which do pose more serious risks. Lasers, for example, can cause harm to humans. At low energy, they are mostly harmless, but they can cause eye damage and at high energy levels be very harmful.
So are there magnetic fields that can harm us? Well, back to the Cancer Institute website. They differentiate electric fields and magnetic fields as separate types of fields, but I think its important to note that the magnetic fields they discuss on their website are created by electricity, even if they are separate and different from the electric fields which are also created by electricity. I also find their explanation that electric fields are easily shielded and that magnetic fields are not. With that in mind, I'll ignore electric fields and focus only on the magnetic fields caused by electricity.
So are magnetic fields caused by electricity different than the magnetic fields caused by magnets (as well as the earth)? If I understand correctly, yes, they are are different, but its not the electricity factor. The differentiating factor is the type of electricity.
Electricity can be alternating current (AC), which we have wired in our homes, and direct current (DC), which is commonly found in batteries. (As a side note, I've always preferred direct current. I find it more manageable and easier to work with.)
EMF-Link [2] says that magnetic fields created by AC electricity cause electrical current to flow in humans and animals that are exposed to them. They also state that magnetic fields caused by DC electricity does not [3]. Whoa! That's very interesting to me.
It looks like my guess that magnetic fields caused by electricity is a broad category is turning out right. The EMF Safety Superstore states:
"EMF (or ElectroMagnetic Field) is a broad term which includes electric fields generated by charged particles, magnetic fields generated by charged particles in motion, and radiated fields such as TV, radio, and microwaves. "[4]
Sources of EMFs
Now that I know a little bit more about EMFs, I'd like to know where they come from. As previously mentioned, EMFs are generated by electricity, but there are some places which have much more EMFs than others, like the areas under high tension electric wires. (A side note about AC electricity: I believe that one of the reasons that AC was chosen over DC as our common electricity was because it travels over long distances better than DC.)
Thankfully, I don't live nearby any high tension wires, and I think the jury is agreed on that matter so I'll instead focus on other sources of EMFs.
Some common home appliances which generate a lot more EMFs than others. Examples include:
- Microwave Ovens
- WiFi Networking Equipment
- Cellular Phones
- Hair Dryers
- Electric Blankets
I don't use a hair dryer or an electric blanket, but I do use a microwave, wifi networking equipment, and a cellular phone. Of those, the only one I use regularly is my wifi. Fact is, however, even if I didn't use my own on a regular basis, I'd still be exposed to the great majority of wifi networking equipment which is found in my neighborhood. Its also interesting to note that these devices are typically on twenty four hours a day, whereas I don't know of anyone who uses any of the other appliances listed twenty four hours a day. I'm certain that some people use their cellular phones way more than I do though. Still, not twenty four hours a day!
Because I work in technology and am generally interested in networking equipment, I'll focus only on wifi equipment from here on. I already knew a little bit about the radio waves (radio waves are indeed magnetic fields created by electricity) created by wifi equipment: its the same type of wave used by microwave ovens, only at a much, much lower intensity.
As I understood it, the IEEE (Institute of Electrical and Electronics Engineers, the standards group which created the wifi specification) decided the acceptable microwave levels for consumer products. Product manufacturers are required to abide by the limits. That sounds fine, but what about the fact that when I go to select the wireless network I am connected to, there are about 20-30 choices available. Does this mean that I am getting exposed to 20-30 times the EMFs? I hope not! I'd hope that the IEEE would have thought of this circumstance and I suspect that EMF exposure levels are not cumulative, meaning that if one wifi transmitter creates ten levels of exposure, two transmitters do not create twenty levels of exposure - but again, I don't know if that is true or not. Even if it is true, I have to wonder why? Is it due to antennas (antennas can greatly affect the distribution of radio waves) or is it due to the probability that the transmitters are on different frequencies? (I've heard about radiation therapy, yes another type of electromagnetic field, where multiple non-lethal rays of radiation are united at a point where cancer resides to kill it and not the surrounding tissue - interesting, no?)
Obviously, I've got more research to-do, but I'll save that for my networking blog. For now, let me conclude with some findings on what the health community thinks about EMFs.
What does the scientific and health community think about EMFs?
Like many health related studies, most of what I've read is "inconclusive".
The Cancer Institute seems to think that EMFs are not their greatest concern [1], even when it comes to cellphones [5]. Reading a little bit deeper, it sounds like they are saying that there isn't enough evidence for them to take a strong stance one way or the other, and that they are leaving the door open for more scientific evidence.
Wikipedia also says that studies conducted on the subject have not indicated that EMFs cause health risks, and again states that more testing and evidence is needed [6][7]. Wikipedia did go so far as to say that power transmission can lead to health problems:
"
childhood leukemia, adult leukemia, neurodegenerative diseases (such as amyotrophic lateral sclerosis), miscarriage, and clinical depression." [8].
The American Council on Science and Health website has an article that suggests to me that they think the whole idea of health risks caused by magnetic fields is hogwash [9].
Based upon the very limited research I've done in the past hour or so while writing this blog post and my fairly conservative position when it comes to health and altering otherwise relatively healthy lifestyles of the past several hundred years (yes that is coming from someone who writes software for a living!), I'll play it safe and try to minimize my exposure to EMFs.
I'll go on to say that I think it would be unwise for governing bodies and research groups to not rigorously pursue further investigation into this matter. One of the more frightening potential risks caused by EMFs included DNA fragmentation - yikes! I'm not a scientist or a doctor, but that sounds scary. Another freaky sounding risk is the potential for EMFs, especially from cell phones because we hold them to our ears, to break down the "brain-blood barrier" [10]. Again, the research study I reference here says:
"More studies are needed to demonstrate the effects of RFR on the permeability of BBB and the mechanisms of that breakdown."
In closing, to play "Devil's Advocate", I'll also state that there is a possibility that the benefits (increased understanding, better health education, etc.) that cellphones and communications technology present outweigh the health risks. I also got the impression that while some health and science boards are leaving the door open to more studies about the health risks, they feel that there are well understood and even glaringly obvious health risks which plague our civilization: smoking, car accidents, alcoholism, obesity... the list goes on. Clear and present dangers, one might say.
References:
- http://www.cancer.gov/cancertopics/factsheet/Risk/magnetic-fields
- http://infoventures.com/private/federal/q&a/qa-intr6.html
- http://infoventures.com/private/federal/q&a/qa-intr7.html
- http://www.lessemf.com/emf-news.html
- http://www.cancer.gov/cancertopics/factsheet/Risk/cellphones
- http://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health#Mobile_telephones
- http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health
- http://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health#Health_effects_of_electric_power_transmission
- http://www.acsh.org/factsfears/newsid.570/news_detail.asp
- http://www.ncbi.nlm.nih.gov/pubmed/19811403?dopt=Abstract
