There have been a number of exhaustive studies over the years looking for a link between the electromagnetic radiation emitted by cell phones and other wireless devices, and cancer, especially brain tumors. So far they’ve been inconclusive at best, and almost all of them have found no evidence for a link at all. But now a new, long term study in rodents has reportedly produced a possible statistical correlation, it’s being taken seriously, and needless to say, just the possibility has plenty of people alarmed:
About 2 to 3 percent of the male rats in many of the dose groups developed malignant glioma, a form of brain cancer, while none in the control group did. Up to 3 percent of the rats in the different exposure groups developed precancerous brain lesions, while again none in the control group did.
The authors said the trend toward higher risk was statistically significant for the CDMA radiation but not for the GSM.
The evidence of risk of cardiac tumors was somewhat stronger. In the groups given the highest dosage, 5 to 7 percent of the male rats developed schwannomas, compared to zero in the control group.
CDMA or Code Division Multiple Access and GSM or Global System for Mobiles are widely used, competing encoding formats for wireless devices. If your phone has a SIM card, it's probably GSM. But there are zillions of different phones on the market. If you do not have a SIM card, it does not necessarily mean your phone network uses CDMA.
To repeat: there have been multiple studies on this and so far no link has been found between cell phones and cancer. To put this study in that context, imagine you had a dozen well-calibrated thermometers all reading 50 degrees on the nose and one lone thermometer that read below freezing. It’s possible something is wrong with the dozen reading high, but the accuracy of that one thermometer would be far and away your first suspect, right? In much the same way, this new study must be viewed with a big dose of healthy skepticism. No doubt submissions are being made and studies are being commissioned at this very time to see if any of these results can be reproduced or nullified.
Frankly, I’m skeptical a link will be found. But this is a new study and so far it appears to have been carried out diligently, so it deserves fresh discussion and consideration. An abbreviated version of this post is scheduled for the front page. Due to emails received by registered members, I’ve created this diary to pursue deeper discussion below the fold.
Looking purely at brain and nerve cancers: neurons don’t reproduce, that’s why spinal cord injuries are so serious. If a cell doesn’t reproduce, it can’t cause a disease defined by uncontrolled reproduction, like cancer. But nerve tissue is way more than neurons. There are supporting cell types threaded through and intertwined with the neural component. One of those is called a glial cell, as the image shows there are several types of them, and they do reproduce. So it’s not surprising that many brain cancers are gliomas, tumors caused by a glial cell that went malignant during reproduction at some point. Another is called a Schwann cell, which is just a glial cell found only in peripheral nerve tissue, outside of the brain. Tumors caused by Schwann cells breaking bad are called schwannomas.
The two types of tumors reported in this new study were gliomas and schwannomas. Oddly, these tumors only occurred in the male subjects. That right there makes me suspicious of a methodology error, though I can’t say exactly what it might be.
When we hear the word radiation we think of atomic bombs, rads, mutants, etc., produced by fissile material like uranium or plutonium. We call it ionizing radiation because it’s strong enough to kick electrons loose from atoms. That kind of radiation includes fast moving particles like neutrons and protons which can rip through DNA in cells like machine bullets through a human body, leaving all kinds of damage behind. Rip through enough cells and the chances the “off switch” for cellular reproduction is damaged in one or more cells grows to a certainty. If some of those cells otherwise survive the onslaught and reproduce, they won’t ever stop, and that’s one way to cause cancer.
But cell phones don’t use that kind of radiation, not even close. They use electromagnetic radiation, which includes everything from radio waves to visible light to UV. Calling radio waves or the color yellow “radiation” is technically accurate, but in this case it’s almost pejorative thanks to things like post apocalyptic sci-fi movies. We call this kind of radiation non-ionizing.
The image right shows the EM spectrum and some of the characteristics at various wavelengths. Note how the visible portion, what we think of as a big part of the EM band, is really just a tiny little section of wavelengths. You can also see that radio and TV — at least old fashioned, non cable TV that floated through the air for free! — uses wavelengths measured in centimeters to meters.
Cell phones and related devices use wavelengths just above TV and radio, roughly between 30 and 40 cm. Short enough that we call them microwaves, but huge compared to anything that can cause tissue damage like gamma rays. In fact, due to the vagaries of quantum mechanics, cell phone waves can’t in effect, even “see” DNA. It might as well be perfectly clear glass as far as those wavelengths are concerned.
So how could these microwaves interact with cells and cause cancer? The short answer is, they can’t. Which is one big reason researchers think that cell phones can’t cause cancer directly. The reasons we think they can’t cause cancer indirectly comes from a number of independent sources.
For starters, the National Institute of Health (NIH) and other organizations like the American Cancer Society maintain large databases of all kinds of health related attributes. They are among the most robust data sets in all of science. Since cell phones are a relatively new creation, and if they caused an increases in cancer of any kind, you would expect it to show up there regardless of how it happens. If the link was straightforward, there would be a jump in cancers lagging behind cell phone usage. We’ve had cell phones in wide use for over 20 years now, plenty enough time for a clear statistical link to appear. The logical conclusion is, If cell phones cause brain/nerve cancer, it’s either 1) extremely rare or 2) some other factor[s] would have to be cluttering the picture and masking an obvious connection.
Secondly, multiple studies have been conducted looking for a link. To date, no clear link has been found -- notwithstanding the study at hand. And lastly, no plausible physiological basis put forward for how it would work has survived experimental scrutiny to date.
So sure, we should be open minded to an extent. We can speculate, and this is pure unfounded speculation. There is a remote possibility of a more complex cause and effect at work. Just as an illustration of that, maybe some specific wavelength juggled in some specific way could cause minor internal damage to living tissue. A tiny bit of heating for example, so subtle the patient doesn’t even feel it. It could be caused by a specific model of phone or one type of circuitry common in phones. As long as we’re clutching at straws, it would be when a specific phone using a specific frequency and specific chip-sets gets wet or dropped too many times and has glitches. If that turned out to be the case, and adult stem cells swing into action to repair or scar, then there might be a plausible pathway to a tumor.
But to avoid clear detection in data sets and a multitude of studies, it would probably have to be a rare thing indeed. The rarer something is, the less you should worry about it. And we’re going to find out the answer: because of this one lone study, you better believe more will be funded and carried out quickly. Let’s wait and see if any of these results can be reproduced, before hitting the panic button.