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FORA.tv Series: Exploring Women's Health

Nancy Snyderman: Medical Myths That Can Kill You

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Francisco J. Hernandez Avatar
Francisco J. Hernandez
Posts: 2
Posted: 12.09.08, 03:36 PM
I would like to ask Ms. Snyderman if she would consider electromagetic contamination to be a kind cancirogen.
Periergeia Avatar
Periergeia
Posts: 142
Posted: 06.08.10, 10:17 PM
I am not a physician, but I can chime in on your question.

The trivial answer is: yes, electromagnetic radiation is a carcinogen. But that answer is pretty useless, because the kinds of radiation that we know for sure to cause cancer are near UV and, X-ray and gamma rays. I have not heard of any research suggesting that visible green or red light causes cancer (but would be interested to see research if someone knows a link!). This means that in all likelihood a mere factor of two in photon energy (between green and near UV) will therefor change the answer. And then, of course, the type of exposure is also of importance. Low doses of UV (and ionizing radiation of higher energy) will cause cell damage but that damage can be repaired by the body (after all, we have evolved in a natural radiation environment, so basically natural selection has given us a pretty good mechanism to deal with the problem). High dose exposure (severe sunburn, radiation sickness) will overwhelm the cell repair mechanisms and lead to non-linear responses (twice the radiation will not cause just twice the likelihood of cancer but a much higher incidence). There is relatively solid research on these things for the case of ionizing radiation and it makes sense to pay attention. No amount of tan is worth skin cancer.

At the other end of the spectrum, there is a pretty good consensus about the thermal and chemical effects of lower frequency electromagnetic radiation (including DC currents) at high field strength. But these effects concern only those who are exposed to known electrical hazards professionally.

Where there is close to no research whatsoever, are the twelve to fifteen orders of magnitude in frequency (depending on where one starts counting) between near DC to line frequency and near UV. The reasons for that are partly experimental. It is extremely hard to actually measure such a wide frequency spectrum with anything approaching the necessary scientific accuracy to draw reliable correlations between exposure and biological effect. Putting the difficulty of determining biological effects aside, just measuring the actual electromagnetic field near a human body reliably is a huge technical problem. Nearfield measurements close to lossy dielectrics are an absolute pain and hardly reliable because the interaction between the antennas and the "body under test" are non-trivial.

And, of course, nobody will put volunteers into a Faraday cage and sweep them with increasing doses of electromagnetic waves over the useful communication bandwidth for weeks, months or years. It's just not practical (let alone ethical). Sadly, as with most substances we are exposed to, long term effects can not be demonstrated with statistical significance except with enormous statistical numbers. That's why we understand the danger of smoking so well (we have tens of thousands of lung cancer patients a year) and have much less reliable data about less common carcinogens.

I had people in the past ask me about the issue because I work with electromagnetic radiation in the frequency range of electronic devices professionally. My usual answer is that nothing that has not been tested exhaustively can be scientifically ruled out (but that's merely a tautology which defines the scientific method and offers next to now help in this case).
At that same time that does not automatically mean there is disproportionate danger. My personal take on it is that if you or your parents were born during or shortly after the atmospheric nuclear tests in the 20th century, I would say that you can forget worrying about your cell phone... you probably got the really big hit already. And that's not hearsay but hard science. There are physical reasons why they stopped testing... the politicians back then certainly didn't just try to win the Peace Nobel Price with that move!

Technically one can do relatively little to reduce the electromagnetic fields that the human body is exposed to in our typical life. Except for putting on "something more metal", the only way to reduce the exposure is by knowing the typical sources and trying to minimize them. Staying away from high voltage lines is, I would say, in general a great idea for all kinds of reasons, not just fear of cancer.

Concerning cell phone use, nobody "needs" to have a 1W transmitter next to the ear for most of the day. One can always use a headset. It's much better for the posture, anyway and that alone will reduce field strength near the brain and most sensitive tissue by nearly an order of magnitude or more.

Just based on geometry and technology, I would guess with some confidence that the next kinds of electromagnetic devices most people deal with all the time (wireless routers etc.) have another order of magnitude lower emissions than a cell phone at full power output.

I believe that the Wifi standard prescribes a software interface which your wireless device uses to communicate the power level of its transmitter to your computer. There are software tools which can display this power level, if the device allows this kind of diagnostics. While this wouldn't tell you how much energy is absorbed in your body, it will, at least, give an indication of how much power is being transmitter close to you.

Beyond that there are the actual computer circuits (which are pretty well shielded, however) and power supplies, which radiate not because they have to but because total shielding is expensive and bulky. These devices are all standardized in their emissions, they are being tested and designed to stay within certain spectral masks and you can dig into the relevant standards of the US, Europe, Japan and China, if you feel like it. Those standards are, of course, designed to make the devices compatible with each other... they are not physiological exposure limits.

Based on anecdotal evidence, an entire industry of physicists, design engineers and technicians working with unshielded devices under benchtop conditions and in the testlab which are exceeding the legal limits for consumer devices, by far, I would not be too concerned. I do know of cases of exposure where people died or got seriously sick from handling electronics, but all of them made some trivial but near lethal mistakes by willingly or accidentally disregarding obvious safety rules when handling or being around power devices with known dangerous power levels. None of that happened next to a consumer device's circuit board or power supply.
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